[Shotimes] BRAKE PROBLEMS (sorta long, but an easy read!)

[Leigh Smith]

Fronts:
Q: Are the pads wearing / grabbing evenly, or just one side?
One side would lead me to suspect pin issues.
My 89 SHO had original calipers & pins with 262 miles. But pin corrosion (in
NJ) caused me to find the pins needed cleaning more frequently than pad
changes, every 20-40k mi vs 60-80k for good $100 pads.
I found I had to emery cloth the pins, and grease them with silicone grease,
and replace the rubber seals occassionally. The pins should slide easily
under light finger pressure. The bracket holes I had to wirebrush /
sandpaper to clean. The pins should slide easily under light finger
pressure. I had one pin rust solid & lock-up in the bracket once.  Wear
clearances weren't the issue, it was rust build-up.

You can also test the front pistons for corrosion, open the bleeder valve,
and you should be able to move the piston with figer pressure, no sticking.
BTW the rear is different here. The rubber seal itself is all the pressure
there is that causes the piston to retract slightly from the rotor.

Rears: Make sure you check for restricted rear flex hoses. Open the bleeder
valve on a caliper and see if the e-brake works better. That brake that
won't grab should improve.

Lee

----- Original Message ----- 
From: "Jim Koper" <jkoper@frankgates.com>
To: <shotimes@autox.team.net>
Sent: Tuesday, February 24, 2004 5:56 PM
Subject: [Shotimes] BRAKE PROBLEMS (sorta long, but an easy read!)


> Hello all,
>
> I have a 92 SHO with 141,000 miles, several BRAKE-RELATED ISSUES.
>
> FRONTS: both are dragging. I already replaced the flex hoses and calipers
> about 1.5 to 2 years ago (Wagner rebuilts). Why do they go bad (stick) so
> soon? Any remedies I am missing? I bleed the brakes every year in
> preparation for the convention, so old brake fluid would not be a factor
in
> the 'return' of the brakes. MPG and performance are obviously down--hate
> running the car like this, as the engine is working much harder than it
> needs to. I cleaned and regreased the fronts, but it didn't make a
> noticeable difference.
>
> If the pins have even wear marks (a series of shinier rings around the
pin),
> do they need replacing or just cleaned and lubed?
>
>
> REARS: After about a year of NOT using the e-brake, I applied it last
week.
> (I know the e-brake adjusts the rear pads as they wear, but I didn't want
it
> freezing up in the winter.) Big mistake. I smelled burnt pads within a few
> miles.  I pulled the wheels to check it out.
>
> Applying and then 'releasing' the e-brake causes the RR caliper to 'lock
up'
> (the return spring on the caliper doesn't return caliper to the 'e-brake
> off' position. I use a pry bar to return the lever to its natural
position.
> Sound familiar?
>
> The LR e-brake cable does pull the caliper lever--however, I can still
spin
> the rotor freely!! How would THAT happen? The pads and rotor seem to be
> wearing, so the hydraulic portion of this work OK.
>
> BTW, I replaced BOTH rear cables 3 years ago. Moisture seems to get in at
> (1) the end near the caliper and (2) where that clear plastic sheathing
> surrounds the coiled cable (middle of the entire cable, near the rear
> control arms).
>
> Any way to recondition the e-brake cables? They are not that old! I've
tried
> PB blaster, a bit of heat, silicone spray, lithium grease on the cables.
>
> Have any of you found the front release cable (connects to the interior
> release handle) to be faulty?
>
> Are the return springs on the rear calipers too weak/bad design and has
> anyone modified them? It seems if they were of a higher tension that they
> could keep the e-brake cable functional.
>
> What do you guys and ladies do to fix such problems (or better yet,
prevent
> them from happening in the first place?
>
> Is the only real solution to replace all four calipers? The rears were
> replaced 3.5 years ago (new pins and boots last year).
>
> Would replacing the MASTER CYLINDER solve the fronts dragging? Anyone
BTDT?
>
> I am fed up with having to look at something on this car every other
> weekend!! I'd like to DRIVE the car for a change!!
> No, I won't trade it for anything else--yet.
>
> Thanks for your input.
>
> Jim Koper
> 92 red/black
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