Upgrading a 1988-93 W-body to 94+ rear brakes
This upgrade will give you totally different calipers and 11" rear rotors
(compared to the old 10.1" rotors). We'll attempt to reuse as many of the
original parts as possible. Before proceeding with this upgrade, be aware that
I have not yet figured out how to implement the park
brake! That's a project for another day. Also, be aware I will not
be held responsible if you damage your car in any way!
Suitable Donor Cars
- 1994-96 Buick Regal and Pontiac Grand Prix
- 1994-97 Oldsmobile Cutlass Supreme
- 1996 Chevrolet Monte Carlo Z34 (optional on LS) or Lumina LS with 3.4L DOHC
V6
- 1997 Chevrolet Monte Carlo/Lumina (all?)
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You will need to get all of the parts shown in the diagram to
the left. You'll need the parts for each side. You will not need #17 and
#18 right away if you are planning to attach the park brake at a later
time. In addition, you will also need:
- 2 rotors (11" diameter)
- 4 caliper-to-knuckle bolts
I purchased my calipers from a salvage yard, parts #2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, and 20 were all included with the calipers. I believe
you will also get all those parts if you buy a caliper from an auto parts
store. The caliper support bracket (23) was not included, but when I requested
the part from the salvage yard, it came with #1, 21, and 22 already attached
to them. They also included spring clips (14) and pads (15, 16). I bought
the rotors brand new from the auto parts store, and they were the majority
of the cost. If you're real frugal, you can probably pick some up from
a salvage yard for $5-10 a piece.
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NOTE: From this point on, anytime you see me referring to numbers
in parenthesis, they're referring to the diagram above.
Before you Start
Before you start the operation, you may want to clean up any used parts you
buy from a salvage yard, and you may also want to paint the parts regardless
of whether you bought them new or used. Most used calipers are a little rusty,
or at the very least, rather crusty. New calipers are usually unpainted cast
iron. A nice coat of paint on your brake parts will keep them looking nicer
for much longer. It doesn't take long for a new caliper and rotor to become
totally rusted in appearance. If you have those fancy open-spoke wheels, the
rusty brake parts will be easily visible. I bought my parts (with the exception
of the rotors) from a salvage yard, so they were rather rusty. I used a Wizard
rotary tool and its wire-brush attachment to remove the rust & crust, and
then used brake cleaner to remove any embedded dirt & crust. I also used
Naval Jelly to etch away some of the rust. Afterwards, I painted my calipers
and the part of the rotors that aren't in contact with the pads. I used Rust-oleum
Cold Galvanizing spray paint. I chose it specifically because it consists of
zinc and aluminum dust. I figure it will not inhibit cooling of the caliper
and rotor due to the fact that it is a metal dust and will also conduct heat.
It's also supposed to prevent rust. The caliper support bracket was originally
painted black. I removed any rust and repainted it black using high-heat Engine
Enamel. I originally wanted my calipers black too, but in the end I decided
it actually looks kind of cool to have light silver calipers and black brackets.
It'll be much easier to paint them now, rather than to try to paint them on
the car. Just something to consider. Before you start, assemble your parts to
look like the pictures of my parts below if necessary.
Caliper Support Brackets freshly painted
(1, 21, 22, and 23)
Calipers freshly painted (2, 3, 4, 5, 6,
7, 8, 9, 10, 11, 12, and 20)
These used brake pads still have a lot of
life left... hey, they were free, can't beat that! (13, 14, 15, 16)
Let's Get Started
- Jack up the car and remove the wheel.
- Remove the rotor dust shield by removing two 8mm bolts and discard it (you
will not be able to use it with the new rotors - newer cars do not have a
dust shield anyway).
[Dust shield removed]
- Loosen the two 18mm bolts that hold the old caliper on.
- Remove the park brake cable from the old caliper.
- Disconnect the brake line from the caliper by removing the bolt from the
coupling.
- Remove the two 18mm caliper-to-knuckle bolts and remove caliper.
[Everything removed]
- Remove the old 10.1" rotor from the hub by pulling it straight off.
It may be very rusted stuck, so you might need a large hammer, a lot
of penetrating oil, and a lot of patience.
[Old and New Rotor - see the
size difference and also the ineffectiveness of the old caliper]
- This would be a good time to coat the hub with anti-seize compound so that
you don't have such a hard time removing rotors next time! Be sure NOT to
get any anti-seize compound on the lug studs.
[Anti-seize on the hub]
- Slide the new 11" rotor onto the hub and use a couple lug nuts to hold
it down.
- Attach the caliper support bracket (23) to the knuckle using two support-to-knuckle
bolts.
[Rotor and bracket installed]
- Push the two spring clips (14) to the caliper support bracket (23).
- Lubricate the surfaces of the spring clips (14) with silicone brake slider
grease.
- Slide the brake pads (15 and 16) onto the spring clips (14).
[Pads and spring clips installed]
- Lubricate the pad outer surfaces and upper slider (22) on the caliper support
bracket (23) with silicone brake slider grease. Take care not to get any on
the pad's active surface or the rotor.
- Slide the caliper onto the caliper support bracket's upper slider (22),
and tilt downwards until the caliper rests on the pads and the support bracket.
- Insert the mounting bolt (1) into the caliper's lower slider (3) and torque
to 32ft-lbs.
- If you are reusing the original flexible brake hose you will need to:
- Remove the bracket that mounts onto the strut. I removed it using a
Wizard rotary tool and cutting attachment. Be very careful not to cut
into the hose itself!!!
- The metal pipe near the caliper end is curved to fit around the old
caliper. If you attach it to the new caliper as it is, the rubber hose
can rub against the sharp base of the strut. This could potentially cause
the strut to wear into the rubber hose, causing a dangerous loss of brake
fluid. You can remove this risk by straightening the metal pipe at the
end. I straightened it rather easily without removing the hose by placing
the metal part on top of base of the strut (where the bracket originally
bolted to), and hitting it with a hammer. It straightened out nicely and
did not collapse the metal pipe.
Alternate Solution: You can probably do a cleaner
install using genuine 94+ metal brake lines and brake hose. The reason I did
not go this route is because the metal brake line would need to be replaced
from in front of the fuel tank all the way to the wheel wells on each side.
This is because the metal brake lines terminate in a different place on 94+,
and that also allows them to use a different (shorter) flexible brake hose
from the brake line to the caliper. You will also have to find your own way
to mount the coupling between the metal brake line and the rubber flex hose,
as an 88-93 doesn't have a place for it. I felt it was much easier just to
modify the existing flexible brake hose.
- Attach the flexible hose to the caliper by tightening the bolt at the coupling.
Torque to 32ft-lbs.
[Finished install, whoopie!]
- Repeat on the other side.
- Bleed the brakes as normal.
- Test the brakes and make sure they work.
You are now ready to move onto Part II - Attaching the Park Brake... currently
not yet done!
My car is an automatic, park brakes are not required to pass inspection
in the state of Missouri, and I hardly ever have to use it. As a result, I haven't
spent much time figuring out a way to hook it up. If you want to take the incentive,
here's what I know about it:
- The park brake cable is completely different from 94+.
- On a 1989 (and probably 1990-93), the end of the driver side cable does
not even resemble the one from 94+.
- On a 1988, both the cable ends resemble that of a 94+ with the exception
that the 1988 cable has springs on the ends.
- The 94+ park brake cabling is routed differently than on a 1988-93.
- It might be possible to attach the park brake cable from a 94+ car
to the existing park brake lever (there is a coupling under the car that is
the same.
- It is not possible to use the park brake lever from a 94+ car. Here's
why.
The End