(updated per date of EDIT)
Allante Boch III ABS brakes - 1987 to 1992
Important note on GM.
- GM to date, has refused to recommend this procedure. Yet we, the Allante crowd, know
without any doubt whatsoever, that the BOSCH III decays rapidly without this procedure.
The system builds up crud, its effects magnified by moisture absorbed on the unsealed system.
The end result being a failed ABS Master Cyl, a very expensive item often exceeding the cost
of a car.
Important note on brake fluid, DOT-3 or DOT-4 -
The BOSCH III ABS - 24 months is the very max the fluid should be
in the system before FLUSHING. i practice 12 months.
- Fresh fluid has a cleansing quality that extends the life of master cyl ($900 rem, $3,000 new),
accumulator ($250 rem to $600 new), high pressure pump ($200). If your system is dirty, FLUSH
more often as that in itself will slowly clean the system. The first time I flushed I continued the process
until I used up the whole gallon. A lot of new clear fluid went in, a lot of dark cruddy fluid came out.
Also, FLUSH the lines.
- the BOSCH III is used in the '87 to '92 models. Not in the '93.
- If i'm wrong on the maint cycle, i will spend an xtra $15 / year, if i'm right i will save from a few $100's
to $1,000's in components.
HIGHLIGHTS :
- get a
FRESH and SEALED gallon of brake fluid, DOT-3 or DOT-4 - you are
going to need that much.
- Know that GM & FORD do NOT require machining of rotors in a brake job,
if the mechanic states that they do, ask for the instruction - there is none. - avoid machining rotors unless damaged and then it is best to
replace with new ones,
they are designed to be machined but you are at the mercy of the lathe operator ...
- DONT forget the anti-chatter clips
- Always OPEN the brake fluid drain valves
BEFORE you retract the caliper pistons,
- leave valves open until caliper and pads are back on rotor, bleeding air out is not anywhere as bad
as replacing a Master Cyl that got fluid reversed into.
- avoid at all costs back-pushing crud fluid, specially on the BOSCH III (1987 - 1992) ,
- FLUSH / BLEED brake lines at each wheel, same as any other GM car,
- IF lines are original OEM, they are OLD -
replace,
- FLUSH the master cylinder, high pressure pump and accumulator ABS,
(detailed instructions at Allantesource.com ) - know that the parking brake adjusts the REAR brakes ..
- know that the parking (e-brake) also sets the RED ABS Light.
CALIPERS:
FRONT calipers - the
C-CLAMP works well in retracting the
front pistons REAR calipers -
NO amount of pressing will move the REAR piston. forget c-clamps, you need a spanner wrench type of tool to retract the rear pistons,
tool # K-D 3163, which is a little metal cube that
attaches to a 3/8" drive and has lugs that fit into the slots on the pistons.
Calipers are the same as equip used in many Cadillac models.
*
PADS, $45 for PREMIUM semi-metallic (Ferro-Compound), $25 for organic - PER AXLE
expect to double that buying PADS at dealer
* soft pads are easy on rotor, make dust, and work well cold
* ceramic pads eat rotors, they dont make much dust, dont work so good cold
* pads, from soft to hard ==>
Organic, Ferro-Compound, Ferro-Carbon, Ceramic, Kevlar-metallic * new calipers, around $40 per.
* new rotors, around $40 per
machined thinner rotors may warp faster with lessened capacity to absorve heat.
Brake Pads:
"In addition to quality organic and semi-metallic brake pads, the ACDelco
DuraStop line offers ceramic brake pads for even better performance."
( be aware that these are exactly that, performance and they wear out rotors FAST )
these are some of what Delco offers:
BONDED
171-556 - PAD KIT,FRT DISC BRK
17D353M - PAD KIT,FRT DISC BRK DURASTOP SEMI MET
RIVETED
171-557 - PAD KIT,RR DISC BRK
17D354M - PAD KIT,RR DISC BRK DURASTOP SEMI MET
Anti-chatter/rattle clips:
The kit is Bendix part# is H5590, GM part# 18060057
approx $8 /wheel
DELCO PARTS SEARCH:
http://198.208.187.182/internet/Vehicle.jsp?application=Car%2FLight+Duty +Truck&year=1988&make=CADILLAC&model=ALLANTE&engine=&selectedfld=model
the DELCO BRAKE QUIZ:
http://www.acdelco.com/acdelcoapp/tech_quizzes/brakes.jsp
it is believed that the rattle in the Allante brakes is caused by a
change in size of the pads, including DELCO pads.
read on ..
quote:
Original by eldobro
I went through this with a 91 Seville, which has the same set-up in the rear. I replaced all the bushings, caliper bolts and clips, but the rattle was still there. I wound up smacking the caliper with a rubber mallet and poking here and there with a screwdriver until I found the problem.
The rattle didn't start until I replaced the original pads. I dug the old pads out of the shop garbage and measured them. I found that they were slightly narrower side to side. That and the wearing of the caliper bracket where they hang caused the rattle. There was room now for them to move around with the caliper when I would hit bumps with the car.
I tried an experiment Using the new pads as a gauge, I had a new surface welded up on the caliper bracket and then cut down so the pads still had clearance side to side, but not enough for the caliper to build up momentum when I hit a bump. I put it all together, drove down a rough road and the rattle was completely gone. after all this time, the rattle has never returned.
