How to Replace a Brake System Flex Hose
Every car has a brake flex hose
this hose is needed because the suspension's horizontal and vertical movement during
normal vehicle operation. This brake flex line is mounted on the frame of the car,
usually with two brake flex hoses in the front and one or two in the rear of the
car. Like any rubber based part these hoses are subjected to road conditions and
must be replace when signs of failure arise. When a brake hose fails it will leak
brake fluid and cause the brake system
to run low on brake fluid causing the brake fluid
Anytime you replace a brake system flex hose the brake system must be bled to relieve
any bubbles that are trapped. If air bubbles remain in the system it will cause
the brake pedal to feel spongy
Before we begin open the car's hood and observe the brake fluid level.
Park your car on level ground with the engine off and the
raise a car according to the manufacturers recommended instructions and secure with
jack stands. Also we will be dealing with brake fluid so be sure to wear protective
clothing, eyewear and gloves.
Tools Needed to Complete this Job
1. Lug wrench
2. Line wrench set
3. Large standard blade screw driver
4. Wrench set
5. Socket wrench set
Parts and Supplies needed to Complete this Job
1. Replacement brake flex hose
2. Shop towels
3. Brake fluid
Step 1 - First remove wheel cover or hub cap. (some cars have the lug nuts exposed,
if so skip to the next step)
Step 2 - Loosen one turn and (do not remove) the lug nuts of the wheel to be
Step 3 - Lift and support car in a safe position high enough to remove the brake
flex hose. A jack is used in most cases, supported by jack stands.
Step 4 - Now remove the remaining lug nuts and remove the wheel.
Step 5 - Loosen the hydraulic brake flex hose at the
block, do not remove.
Step 6 - Loosen the flex hose at the frame or body mount and remove the retainer
Step 7 - Continue removing the hydraulic brake flex hose by completely removing
the flange nuts or bolts. (note: in some cases a copper sealing washer is used between
the hose and caliper or mounting block).
Step 8 - Completely clean all mounting and sealing surfaces.
Step 9 - Re-install new brake hose using new copper sealing washers.
Step 10 - Tighten all mounting bolts and flange nuts to seal the new brake hose.
Step 11 - Bleed
the brake system
Step 12 - Inspect brake flex hose connection for leaks and repair as needed.
Step 13 - Reinstall wheel and lug nuts, lower the tire onto the ground the finish
tightening lug nuts to manufactures torque specifications.
Check the brake pedal operation, it should be normal. Do
not move the vehicle until normal brake operation has resumed
- Trapped air in the brake system.
- When replacing a brake flex hose make sure the copper sealing washer is
- If a brake flex hose fitting has seized, use an anti-rust solvent such as
wd40 or equivalent to help loosen.
If further assistance is needed, our certified car repair technicians are ready
to answer your car questions
. Also, gain manufacturer
specific instructions and information by clicking -
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Article first published 2009-07-28 (Updated 2015-01-02)