Filled with brake fluid the wheel cylinder is subject to heat and moisture. This
can create rust inside the wheel cylinder which will cause the cup seals (2) to
fail and leak brake fluid or seize up and not work at all, brake fluid on the shoes
can cause the brakes to grab and lockup. The front brake system will still work,
with a slightly lower brake pedal position and diminished brake operation. Once
this occurs the wheel cylinder and the
rear brake shoes will
need to be replaced due to the brake fluid contamination.
What Will it Cost?
Typically a wheel cylinder will cost between $11.00 and $25.00 (US) each on Amazon
and the shop time labor is approximately 2.0 hours. If exact labor times or procedures
are needed you can ask our experts to supply you with
the information (free), or consult an online resource such as AllData DIY (pay)
but this guide and video will be sufficient in most cases.
Let's Jump In!
When a wheel cylinder is being replaced it is normal for the
rear brake shoes
to be replaced as well. Brake shoes contain asbestos so avoid using compressed
air to clean, we use water from a hose which helps contain dust partials while
washing brake dust away, spray the drum and components, allow it to dry before
beginning. Wear a dust mask and gloves to help eliminate harmful contaminants.
In the example below the brake shoes have already been removed. This is what
the wheel cylinder looks like when it is ready to be replaced.
The first step is to loosen the brake line from the wheel cylinder,
using a line wrench will help you
avoid rounding the brake line fitting, center the wrench on the fitting completely
before applying pressure. Once loosened, brake fluid will start to drip out
so have a shop towel ready.
Quickly use a vacuum cap to stop the brake fluid from flowing once the line
is completely removed. This is necessary to stop the brake fluid from leaking
so as to not empty the
brake master cylinder,
if this does occur the brake master will need to be bled.
Use a wrench or socket to remove the wheel cylinder mounting bolts (2),
in this case the bolt size is 8mm, rarely wheel cylinders are held in place
by a snap ring.
Gasp the wheel cylinder firmly and remove it from the backing plate.
Watch the Video!
After the video please continue with the remainder of the guide to glean
additional information. Complete rear brake job video.
Remove the new wheel cylinder from its box to match up to the old wheel
cylinder to the new unit, they should match identically.
Insert the wheel cylinder into the backing plate and secure it by installing
the mounting bolts (hand tight).
Use a wrench or ratchet to tighten the wheel cylinder mounting bolts. The
torque setting for these particular bolts is 9 foot pounds.
Remove the dust cap which was installed by the manufacturer to protect the
fitting threads, the brake line must be straight into the wheel cylinder before
the fitting will thread in. Hand thread the brake line fitting into the cylinder
to prevent cross threading.
Use a line wrench to tighten
the brake line. There is no torque tightening setting for this, so a medium
snug will work, do not over tighten.
After the brake shoes and drum have been reinstalled use a small screwdriver
to remove the bleeder cap. This job is typically performed during a rear brake
job, we have broken out the wheel cylinder replacement to help simplify the
repair. Before the wheel cylinder can operate correctly the
brake system will
need to be bled. After the job is complete, recheck the wheel cylinder for