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© 2011 Pearson Education, Inc.All Rights Reserved
Automotive Technology, Fourth EditionJames Halderman
BRAKE BLEEDING METHODS AND PROCEDURES
97
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ObjectivesObjectives
• The student should be able to:– Prepare to take the Brakes (A5) ASE
certification test content area “A” (Hydraulic System Diagnosis and Repair).
– Explain how to bench bleed a master cylinder.
– Describe the proper brake bleeding sequence.
– Describe the single stroke manual brake bleeding procedure.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ObjectivesObjectives
• The student should be able to:– Discuss how to gravity bleed the hydraulic
brake system. – List the steps needed to perform a pressure
bleed procedure. – Discuss how to vacuum bleed a hydraulic
brake system.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
BRAKE BLEEDINGBRAKE BLEEDING
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake BleedingBrake Bleeding
• The Need for Brake Bleeding– Brake bleeding is removing trapped air
from hydraulic system– Air in hydraulic system results in “spongy”
brakes
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake BleedingBrake Bleeding
• The Need for Brake Bleeding– Brake pedal will travel farther than usual
before engaging– Air gets into system when brake line or unit
is opened
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake BleedingBrake Bleeding
• The Need for Brake Bleeding– Air gets into system through poor
connections or holes in lines– Absorption of moisture into fluid can result
in air
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake BleedingBrake Bleeding
• Bench Bleeding the Master Cylinder– Master cylinder located at highest section
of braking system– Some master cylinders have bleeder valves
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake BleedingBrake Bleeding
• Bench Bleeding the Master Cylinder– If no bleeder valve, loosen brake line
fittings at master cylinder– Bleed master cylinder on the bench before
installing
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 97-1 Bench bleeding a master cylinder. Always clamp a master cylinder in a vise by the mounting flange to prevent distortion of the cylinder bore. Bench bleeding tubes can also be used that route the fluid back into the reservoir.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake BleedingBrake Bleeding
• On-Vehicle Master Cylinder Bleeding– STEP 1: Fill master cylinder with brake fluid.
• Use fluid from sealed container• Fill to full level
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake BleedingBrake Bleeding
• On-Vehicle Master Cylinder Bleeding– STEP 2: Have assistant slowly depress
brake pedal as you open master cylinder bleed screw.
• Important: bleed primary section of master cylinder first
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake BleedingBrake Bleeding
• On-Vehicle Master Cylinder Bleeding– STEP 2: Have assistant slowly depress
brake pedal as you open master cylinder bleed screw.
• Before brake pedal reaches floor, close bleeder valve
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake BleedingBrake Bleeding
• NOTE: A proper manual bleeding of the hydraulic system requires that accurate communications occur between the person depressing the brake pedal and the person opening and closing the bleeder valve(s). The bleeder valve (also called bleed valve) should be open only when the brake pedal is being depressed.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake BleedingBrake Bleeding
• NOTE: The valve must be closed when the brake pedal is released to prevent air from being drawn into the system.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake BleedingBrake Bleeding
• On-Vehicle Master Cylinder Bleeding– STEP 3: Repeat procedure several times.
• Solid flow of brake fluid should be seen
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake BleedingBrake Bleeding
• On-Vehicle Master Cylinder Bleeding– STEP 3: Repeat procedure several times.
• If cylinder lacks bleeder valve, loosen outlet tube nuts
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
BRAKE BRAKE BLEEDER VALVEBLEEDER VALVE
LOOSENING METHODSLOOSENING METHODS
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Bleeder Valve Loosening Brake Bleeder Valve Loosening MethodsMethods
• Opening bleeder valve can cause sheering off of valve
• Bleeder valves are tapered• Can become wedged in caliper
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 97-2 Typical bleeder valve from a disc brake caliper. The arrows point to the taper section that does the actual sealing. It is this taper that requires a shock to loosen. If the bleeder is simply turned with a wrench, the bleeder usually breaks off because the tapered part at the bottom remains adhered to the caliper or wheel cylinder. Once loosened, brake fluid flows around the taper and out through the hole in the side of the bleeder valve. The hole is clogged in this example and needs to be cleaned out.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 97-3 Typical bleeder locations. Note that the combination valve and master cylinder shown do not have bleeder valves; therefore, bleeding is accomplished by loosening the brake line at the outlet ports.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Bleeder Valve Loosening Brake Bleeder Valve Loosening MethodsMethods
• Several methods to loosen stuck valves• Hit and Tap Method
– STEP 1: Apply penetrating oil to lubricate threads.
• Tap on end of bleeder valve with steel hammer
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Bleeder Valve Loosening Brake Bleeder Valve Loosening MethodsMethods
• Several methods to loosen stuck valves• Hit and Tap Method
– STEP 2: Using a 6-point wrench or socket, tap valve in clockwise direction (tighten).
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Bleeder Valve Loosening Brake Bleeder Valve Loosening MethodsMethods
• Several methods to loosen stuck valves• Hit and Tap Method
– STEP 3: Using 6-point wrench or socket, tap valve counter-clockwise to loose and remove.
• NOTE: It is the shock of the tap on the wrench that breaks loose the bleeder valve. Simply pulling on the wrench often results in breaking off the bleeder.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Bleeder Valve Loosening Brake Bleeder Valve Loosening MethodsMethods
• Several methods to loosen stuck valves• Hit and Tap Method
– STEP 4: If valve still frozen, repeat Steps 1 through 3.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Bleeder Valve Loosening Brake Bleeder Valve Loosening MethodsMethods
• Air Punch Method– Apply penetrating oil– Use air punch near bleeder valve– Simultaneously, try to loosen valve
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 97-4 Using an air punch next to the bleeder valve to help “break the taper” on the bleeder valve.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Bleeder Valve Loosening Brake Bleeder Valve Loosening MethodsMethods
• Heat and Tap Method– Heat area around bleeder valve with torch– Heat expands size of hole
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Bleeder Valve Loosening Brake Bleeder Valve Loosening MethodsMethods
• Heat and Tap Method– Usually bleeder can be loosened and
removed– Try turning valve clockwise (tighten) first
before turning counter-clockwise to loosen
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Bleeder Valve Loosening Brake Bleeder Valve Loosening MethodsMethods
• Heat and Tap Method– CAUTION: The heat from a torch will
damage the rubber seals inside the caliper or wheel cylinder. Using heat to free a stuck bleeder valve will require that all internal rubber parts be replaced.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Bleeder Valve Loosening Brake Bleeder Valve Loosening MethodsMethods
• Wax Method– STEP 1: Heat bleeder valve with torch.
• Heat causes valve to expand
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Bleeder Valve Loosening Brake Bleeder Valve Loosening MethodsMethods
• Wax Method– STEP 2: Remove heat from valve.
• As valve cools, touch paraffin or candle wax to hot valve
• Wax will melt and enter threads
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Bleeder Valve Loosening Brake Bleeder Valve Loosening MethodsMethods
• Wax Method– STEP 3: Allow bleeder to cool until it can be
touched.• Wax should be returned to solid form • Cooled wax lubricates threads
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Bleeder Valve Loosening Brake Bleeder Valve Loosening MethodsMethods
• Wax Method– STEP 3: Allow bleeder to cool until it can be
touched.• Try turning valve clockwise (tighten) first
before turning counter-clockwise to loosen
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
BLEEDING SEQUENCEBLEEDING SEQUENCE
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Bleeding SequenceBleeding Sequence
• Bleeding Sequence– Bleed master cylinder first– Then bleed combination valve, if equipped
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Bleeding SequenceBleeding Sequence
• Bleeding Sequence– Check master cylinder frequently; do not
allow to run dry– Start bleeding with wheel farthest from
master cylinder– Work toward wheel closest to master
cylinder
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Bleeding SequenceBleeding Sequence
• Bleeding Sequence– Sequence for most vehicles
1. Right rear2. Left rear
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Bleeding SequenceBleeding Sequence
• Bleeding Sequence– Sequence for most vehicles
3. Right front4. Left front
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 97-5 Most vehicle manufacturers recommend starting the brake bleeding process at the rear wheel farthest from the master cylinder.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Bleeding SequenceBleeding Sequence
• Bleeding Sequence– NOTE: If the vehicle has two wheel
cylinders on one brake, bleed the upper wheel cylinder first.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Bleeding SequenceBleeding Sequence
• Bleeding Sequence– If vehicle has diagonal split section or ABS,
follow procedure recommended by manufacturer
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Bleeding SequenceBleeding Sequence
• Bleeding Sequence– Two most common sequences for bleeding
brakes for diagonal-split system:• RR, LR, RF, LF
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Bleeding SequenceBleeding Sequence
• Bleeding Sequence– Two most common sequences for bleeding
brakes for diagonal-split system:• RF, LF, RR, LR
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
MANUAL BLEEDINGMANUAL BLEEDING
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Manual BleedingManual Bleeding
• Most commonly used method• Also called single stroke bleeding
method
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Manual BleedingManual Bleeding
• Items Needed for Manual Bleeding– Assistant to apply and release brake pedal– Bleeder screw wrench
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Manual BleedingManual Bleeding
• Items Needed for Manual Bleeding– Two feet of clear, plastic hose; small
enough to fit snugly over bleeder screws– Clean jar partially filled with clean brake
fluid
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Manual BleedingManual Bleeding
• Manual Bleeding Procedure– STEP 1: Discharge vacuum or hydraulic
power booster (if equipped) by pumping brakes with ignition off.
• Pump until pedal feels hard
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Manual BleedingManual Bleeding
• Manual Bleeding Procedure– STEP 2: Fill master cylinder reservoir.
• Make sure it is at least half full throughout procedure
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Manual BleedingManual Bleeding
• Manual Bleeding Procedure– STEP 3: Attach plastic hose to bleeder
screw of fist wheel cylinder.• Submerge end of tube in jar of brake fluid
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 97-6 Bleeding brakes using clear plastic tubing makes it easy to see air bubbles. Submerging the hose in a container of clean brake fluid helps ensure that all of the air will be purged by the system.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Manual BleedingManual Bleeding
• Manual Bleeding Procedure– STEP 4: Have assistant apply brake slowly
and lightly.• Open bleeder valve one-half turn
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Manual BleedingManual Bleeding
• Manual Bleeding Procedure– STEP 5: Tighten bleeder screw.
• Have assistant slowly release brake pedal
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Manual BleedingManual Bleeding
• Manual Bleeding Procedure– STEP 6: Wait at least 15 seconds to allow
tiny bubbles to form larger bubbles.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Manual BleedingManual Bleeding
• Manual Bleeding Procedure– STEP 7: Repeat steps 4 and 5 until no more
air bubbles emerge.– STEP 8: Transfer plastic hose to bleeder
screw of next wheel cylinder.• Repeat steps 4 through 7
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Manual BleedingManual Bleeding
• Manual Bleeding Procedure– STEP 8: Transfer plastic hose to bleeder
screw of next wheel cylinder.• Continue around vehicle until all brakes
have been bled
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
VACUUM BLEEDINGVACUUM BLEEDING
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Vacuum BleedingVacuum Bleeding
• Uses special suction pump that attaches to bleeder screw
• Advantages of Vacuum Bleeding– Requires only one technician– Easy and equipment is inexpensive
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Vacuum BleedingVacuum Bleeding
• Disadvantages of Vacuum Bleeding– Vacuum tool must be used– Air can be drawn into line between bleeder
valve and hose, creating bubbles– Bubbles can be interpreted as air in system
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Vacuum BleedingVacuum Bleeding
• Vacuum Bleeding Procedure– STEP 1: Fill master cylinder with new brake
fluid.• Make sure cylinder remains at least half full
throughout procedure
– STEP 2: Attach plastic tube from vacuum bleeder to bleeder screw of first wheel cylinder.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 97-7 Using a compressed air-powered vacuum bleeder.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 97-8 Vacuum bleeding uses atmospheric pressure to force brake fluid through the hydraulic system.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Vacuum BleedingVacuum Bleeding
• Vacuum Bleeding Procedure– STEP 3: Operate the bleeder to create
partial vacuum in catch bottle.– STEP 4: Loosen bleeder screw
approximately one-half turn.• Brake fluid and bubbles will flow into bottle
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Vacuum BleedingVacuum Bleeding
• Vacuum Bleeding Procedure– STEP 4: Loosen bleeder screw
approximately one-half turn.• When fluid is free of bubbles, tighten
bleeder screw
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Vacuum BleedingVacuum Bleeding
• Vacuum Bleeding Procedure– STEP 5: Repeat steps 3 and 4 until no more
air bubbles emerge from bleeder.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Vacuum BleedingVacuum Bleeding
• Vacuum Bleeding Procedure– STEP 6: Transfer the vacuum bleeder to the
next wheel cylinder or caliper in bleeding sequence.
• Repeat steps 3 and 4
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
GRAVITY BLEEDINGGRAVITY BLEEDING
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Gravity BleedingGravity Bleeding
• Gravity bleeding is slow but effective• Procedure involves opening bleeder
valve and waiting until brake fluid flows from open valve
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Gravity BleedingGravity Bleeding
• Trapped air will rise and escape• May take several minutes before brake
fluid escapes
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 97-9 Gravity bleeding is simply opening the bleeder valve and allowing gravity to force the brake fluid out of the bleeder valve. Because air is lighter than brake fluid all of the air escapes before the brake fluid runs out.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Gravity BleedingGravity Bleeding
• Advantages of Gravity Bleeding– All four brakes can be bled simultaneously– Bleeder screws on all four wheels are
opened– System allowed to drain naturally
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Gravity BleedingGravity Bleeding
• Disadvantages of Gravity Bleeding– Can take an hour or more– Cannot be used on brake systems with
residual pressure check valves
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Gravity BleedingGravity Bleeding
• Gravity Bleeding Procedure– Equipment
• Bleeder wrench• Four lengths of plastic hose that fit over
bleeder screws• Four jars to catch dripping fluid
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Gravity BleedingGravity Bleeding
• Gravity Bleeding Procedure– STEP 1: Fill master cylinder reservoir with
new brake fluid.• Ensure reservoir stays at least half full
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Gravity BleedingGravity Bleeding
• Gravity Bleeding Procedure– STEP 2: Attach plastic tubing to each
bleeder screw.• Place ends in jars• Open each bleeder screw approximately one
full turn
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Gravity BleedingGravity Bleeding
• Gravity Bleeding Procedure– STEP 2: Attach plastic tubing to each
bleeder screw.• Allow system to drain• Drain until fluid is free of bubbles
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Gravity BleedingGravity Bleeding
• Gravity Bleeding Procedure– STEP 2: Attach plastic tubing to each
bleeder screw.• If no brake fluid drains out, remove valve; it
may be clogged• Do not press on brake pedal
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Gravity BleedingGravity Bleeding
• Gravity Bleeding Procedure– STEP 3: Close bleeder screws.
• Fill master cylinder reservoir to maximum level
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
PRESSURE BLEEDINGPRESSURE BLEEDING
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Sometimes called power bleeding• Pressure bleeder attached to master
cylinder forces fluid from system
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Tools Required– Plastic hose– Jar to catch fluid– Pressure bleeder—source of air pressure
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Tools Required– Adapter to attach pressure bleeder to
master cylinder fluid reservoir– Some adapters use flat, plate-type
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Tools Required– Adapter seals against same surface as
reservoir cover• Some plastic master cylinder reservoirs
require adapters that seal against bottom of reservoir
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 97-10 A typical pressure bleeder. The brake fluid inside is pressurized with air pressure in the air chamber. This air pressure is applied to the brake fluid in the upper section. A rubber diaphragm separates the air from the brake fluid.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 97-11 Brake fluid under pressure from the power bleeder is applied to the top of the master cylinder. It is very important that the proper adapter be used for the master cylinder. Failure to use the correct adapter or failure to release the pressure on the brake fluid before removing the adapter can cause fluid to escape under pressure.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Metering Valve Override Tools– Metering valve override tool needed in
addition to other tools– Override tool deactivates metering valve
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Metering Valve Override Tools– Pressure of power bleeder within range
where metering valve will block fluid flow– Metering valve that requires override tool
has stem or button on one end
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Metering Valve Override Tools– To install override tool on GM vehicle,
loosen combination valve mounting bolt– Slip the slot in the tool over bolt head
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Metering Valve Override Tools– Push end of tool toward valve body until it
depresses valve plunger– Tighten mounting bolt
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Metering Valve Override Tools– Some Ford vehicles have metering valve
with stem– Stem must be pushed in to bleed front
brakes
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Metering Valve Override Tools– Ford does not have special tool– Assistant needed to override valve
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Metering Valve Override Tools– On older Chrysler and Ford vehicles, slip
one fork of tool under rubber boot– Slip other fork under valve step head
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 97-12 Metering valve override tool on a General Motors vehicle.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Pressure Bleeding Procedure– STEP 1: Consult manufacturer’s
instructions.• Fill pressure bleeder with proper type of
brake fluid
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Pressure Bleeding Procedure– STEP 2: Make sure bleeder is sealed and
fluid supply valve is closed.• Use compressed air to pressurize bleeder to
about 30 PSI (207 kPa)
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Pressure Bleeding Procedure– STEP 3: Override metering valve if
necessary.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 97-13 Pull-out-type metering valves being held out using a special override tool.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Pressure Bleeding Procedure– STEP 4: Clean top of master cylinder.
• Remove master cylinder cover• Clean around gasket surface
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Pressure Bleeding Procedure– STEP 5: Fill reservoir about half full of new
brake fluid.• Install pressure bleeder adapter
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Pressure Bleeding Procedure– STEP 6: Connect pressure bleeder fluid
supply hose to adapter.– STEP 7: Open fluid supply valve on
pressure bleeder.• Check carefully for fluid leans that can
damage vehicle finish
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Pressure Bleeding Procedure– STEP 8: Slip plastic hose over bleeder
screw of first wheel cylinder or caliper.• Submerge other end in jar of brake fluid
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Pressure Bleeding Procedure– STEP 9: Open bleeder screw about one-half
turn.• Let fluid run out until air bubbles no longer
emerge
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Pressure Bleeding Procedure– STEP 10: Transfer plastic hose to bleeder
screw of next wheel cylinder.• Continue until all four wheels completed
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Pressure Bleeding Procedure– STEP 11: Remove metering override tool.– STEP 12: Close fluid supply valve on
pressure bleeder.– STEP 13: Shut off or disconnect shop air
supply before removing master cylinder adapter.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Pressure Bleeding Procedure– STEP 14: Wrap end of fluid supply hose in
shop towel.• Disconnect from master cylinder adapter
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Pressure BleedingPressure Bleeding
• Pressure Bleeding Procedure– STEP 15: Remove master cylinder adapter.
• Adjust fluid level to full point• Install fluid reservoir cover
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
HYDRAULIC ABS HYDRAULIC ABS SERVICESERVICE
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Hydraulic ABS ServiceHydraulic ABS Service
• Check Service Information– Always check service information for exact
vehicle being serviced
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Hydraulic ABS ServiceHydraulic ABS Service
• Bleeding the Electric-Hydraulic Assembly– Sometimes brake pedal will feel spongy
even after four wheel cylinders have been bled
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Hydraulic ABS ServiceHydraulic ABS Service
• Bleeding the Electric-Hydraulic Assembly– Air can be trapped in ABS electronic-
hydraulic (E-H) assembly– Bleeding out E-H unit purges out older
brake fluid– Use only DOT 3 brake fluid in antilock
braking system
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Hydraulic ABS ServiceHydraulic ABS Service
• Bleeding the Electric-Hydraulic Assembly– CAUTION: Some ABS units require that the
brake pedal be depressed as many as 40 times to discharge brake fluid fully from the accumulator. Failure to discharge the accumulator fully can show that the brake fluid level is too low. If additional brake fluid is added, the fluid could overflow the reservoir during an ABS stop when the accumulator discharges brake fluid back into the reservoir.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Hydraulic ABS ServiceHydraulic ABS Service
• Manually Bleeding ABS Wheel Brakes– During brake service, avoid letting air enter
hydraulic system1. Do not allow brake system to run dry.
– Use brake pedal depressor or plug open brake line to keep fluid from flowing out of brake master cylinder reservoir
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Hydraulic ABS ServiceHydraulic ABS Service
• Manually Bleeding ABS Wheel Brakes– During brake service, avoid letting air enter
hydraulic system2. Check master cylinder reservoir often.
– Keep it filled with fluid
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Hydraulic ABS ServiceHydraulic ABS Service
• Manually Bleeding ABS Wheel Brakes– During brake service, avoid letting air enter
hydraulic system3. Bench bleed replacement master cylinder
to prevent introducing air into hydraulic system.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Hydraulic ABS ServiceHydraulic ABS Service
• Manually Bleeding ABS Wheel Brakes– Depress unit per manufacturer’s
recommended procedure– Bleed brakes using same procedure used
for vehicle without ABS
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 97-14 Special bleed valve tools are often required when bleeding some ABS units such as the Kelsey-Hayes 4WAL system.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 97-15 Two bleed valve tools are needed to bleed the Kelsey-Hayes 4WAL system, which attaches to the bleeder valves on the accumulator.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Hydraulic ABS ServiceHydraulic ABS Service
• Scan Tool Bleeding– STEP 1: Check service information for
specific procedure.• Usually involves manually bleeding wheel
brakes before using scan tool
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Hydraulic ABS ServiceHydraulic ABS Service
• Scan Tool Bleeding– STEP 2: Use factory scan tool or one
capable of performing automated bleed procedure.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Hydraulic ABS ServiceHydraulic ABS Service
• Scan Tool Bleeding– STEP 3: Connect scan tool to data link
connector (DLC).• Connector may be located under the dash,
in center console, or covered by a panel
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 97-16 To perform an automated brake bleed procedure on an antilock braking system, first connect a factory or enhanced scan tool to the data link connector (DLC) located under the dash on this vehicle.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Hydraulic ABS ServiceHydraulic ABS Service
• Scan Tool Bleeding– STEP 4: Enter vehicle information shown on
display.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 97-17 Access the menu that includes antilock brake system (ABS) functions.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Hydraulic ABS ServiceHydraulic ABS Service
• Scan Tool Bleeding– STEP 5: Select ABS automated bleed from
ABS menu.– Follow instructions on scan tool
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 97-18 Scroll through the menus and select automated bleed procedure and follow the on-screen instructions.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
BRAKE FLUIDBRAKE FLUIDREPLACEMENT/REPLACEMENT/
FLUSHINGFLUSHING
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Fluid Replacement/FlushingBrake Fluid Replacement/Flushing
• Flushing Procedure– Tools required
• An assistant to pump brake pedal• Bleeder screw wrench
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Fluid Replacement/FlushingBrake Fluid Replacement/Flushing
• Flushing Procedure– Tools required
• About 2 feet of clear, plastic hose to fit over bleeder screw
• Jar partially filled with clean brake fluid
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Fluid Replacement/FlushingBrake Fluid Replacement/Flushing
• Flushing Procedure– STEP 1: Using turkey baster, remove old
brake fluid from master cylinder reservoir.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 97-19 A turkey baster can be used to remove the old brake fluid from the master cylinder reservoir. A rubber hose was attached to the end of the turkey baster to get access to the brake fluid.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Fluid Replacement/FlushingBrake Fluid Replacement/Flushing
• Flushing Procedure– STEP 2: Fill master cylinder reservoir with
new brake fluid.– STEP 3: Slip plastic hose over bleeder
screw of wheel cylinder to be bled.• Submerge tube in jar of brake fluid
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Fluid Replacement/FlushingBrake Fluid Replacement/Flushing
• Flushing Procedure– STEP 4: Open bleeder screw approximately
one-half turn.– STEP 5: With bleeder screw open, have
assistant slowly depress brake pedal.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Fluid Replacement/FlushingBrake Fluid Replacement/Flushing
• Flushing Procedure– STEP 6: While assistant holds down brake
pedal, close bleeder screw.– STEP 7: Continue to bleed each wheel until
fluid from bleeder screw is free of discoloration and contamination.
97 BRAKE BLEEDING METHODS AND PROCEDURES
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Brake Fluid Replacement/FlushingBrake Fluid Replacement/Flushing
• Flushing Procedure– STEP 8: Repeat steps 4 through 7 at each
bleeder screw in recommended sequence.– STEP 9: Check brakes for proper operation.
• Re-bleed if necessary