TSTE Brakes - finally had a issue.

[twalt13]

After 3 TGP/TSTEs I finally had a near death experience with my brakes this A.M.

 

I think the ABS pump is failing as my front calipers have been dragging for a few days and this A.M. they failed (front brakes were smoking) and I had a high idle (3k until I shut it off when in Neutral). With the system depressurized pump runs for 25 seconds. Also it only takes 14 pumps of the pedal and the system is depressurized.

 

If its something simple I'll keep the ABS, if not its VAC brake time for me.

 

Last weekend doing some preventive maintenance I sucked out some of the old brake fluid, replaced it with some DOT III/ IV, didnt take enough out to need to bleed the Master Cylinder unit. Took out all the relays cleaned them up and reconnected them.

[White93z34]

What makes you think the pump is failing? Its usually a YES or NO thing.

 

Then you have 2 critical components that stand in between you and the motor, the pressure switch and relay.

 

With the system depressurized 25 seconds is perfectly normal for it to re-pressurize the system, IIRC 30-60 seconds is normal.

 

How often does the motor run? when was the accumulator last changed?

 

the 3k idle would have nothing to do with the brakes.

 

What condition are the front sliders in? Are the rear calipers even working? I could see unnecessary load on the front brakes if the rear calipers are inoperative. What conditions of driving lead to the brakes smoking.

[twalt13]

Chris,

 

I put my digital thermoter on the brakes once I nursed it back home;

 

FL 210 degrees FR 200 degrees

 

RL 90 degrees RR 80 degrees

 

Stock brakes all around

 

I have 2001 W-body rear knuckles to include aluminum Grand Am brakes & rotors for the rear

.

For the front I am getting brackets fabricated to run some F-body brakes.

 

New accumulator / motor doesnt run that often (shoudl run after 2 or 3 pedal presses - it doesnt).

 

Will take apart the fronts tonight after work. (to check sliders / inner pads etc).

 

Was normal driving in traffic (no hard stops)

 

Both front calipers seemed to be sticking.

 

Which relay runs the motor - the 5 prong one or the 6 prong one?

[White93z34]

its the 5 prong relay under the master cyl cap and to the driver side.

[White93z34]

On thing that dogged me for a long time was corrosion in the pressure switch plug, it created all sorts of intermittent issues.

[twalt13]

Thanks Chris I'll look into that.

 

The rear fluid section had "creame/ white" looking fluid in it when I checked at home tonight. I think I may have put DOT IV fluid in there instead of DOT III.... Trash was already taken out, to verify and that is what I run in my other cars (DOT IV).

Edited May 16, 2013 by twalt13

[White93z34]

My PMIII always does the same thing, let it sit for a little bit and it will clear up. I think it just gets aiirated when you depressurize the system.

[twalt13]

Ends up a piston on each side of the front was sticking (dual piston calipers). Replaced front calipers, and did a complete flush. Now everything seems normal again. Thanks for the assistance Chris.