2nd Gen Non-Engine/Transmission Brake weirdness

[dan_gilson]

My driveway slopes down to the street. Friday going to work I popped the parking brake and the truck did not move. About 2 seconds later it seems like the parking brake finally released. At the 1st stop sign the brakes were a little grabby. And again I got some grab at the signal.



I pulled the rear wheels and drums off today and did not really find anything wrong. The left side did have a lot of brake dust. I gave everything a good shot of brake clean just because I had it opened.



I had reaplaced everything with new EGR stuff a couple of months ago. There seems to be very little wear on the rear shoes. They are working good though. I can definitely tell that they are there. I had a panic stop about a week ago and got all the way into the ABS. Both front and rear did their thing.



I have occasionally got a slight pull under initial hard braking. Someimes right and sometimes left. Most of the time it does not repeat itself. Also, occasionally I get a harder than normal pedal. It also is a no repeater.



Anyone out there have any thoughts/suggestions? I am kind of baffled. It is not like it is not stopping OK but it has just been a little weird.

 

[illflem]

In high humidity or rainy weather the drums rust and will grab for a couple of stops till the rust wears off. Modern low asbestos shoes will also swell when wet and can grab till they dry. Parking your truck with wet brakes before a below freezing night and setting the E-brake will sometimes freeze the shoes to the drum and cause them to not release.

 

[Clinton]

hard pedal...

Does either your ABS or Brake light on the dash light when you notice the hard pedal? I had the hard pedal after a brake job and my warning lights indicated something being wrong. I think my problems were associated with the booster's check valve. DC used a flapper-type valve until '98 (I think that's right, somebody correct me if I'm wrong) when they switched to a spring-type valve. Basically, I think my booster got low vacuum until my flapper check valve got on track. A few laps around the 'hood and it returned to normal. Every now and again right after I start the truck those lights will stay on (longer than a bulb check), but will go off after the system builds vacuum. I'd like to replace the check valve. Hard pedal is often a low vacuum (to the booster) situation. You would need a vacuum tool / guage to diagnose for sure. Sometimes if there is a leak, you can rev the engine up pretty good right before shutting it down and you'll hear the hiss of the leak (Illflem taught me that when I had my problem).



I would think your other weirdness is wet weather related.

 

[Bigramguy]

I think illflem is probably right,might also want to check for a sticking park brake cable.



The vacuum booster is only applicable on 94-96 trucks,in 97 they went to hydroboost

 

[dan_gilson]

It has not rained here for a couple of days but the ground is still really wet. There is high humidity. But has only been sitting over night.



No ABS light or MIL codes.



It is not that cold here were things freeze.



I did check the cables and they seem OK. I could probably do some more investigation here.



I did hit some of the internal parts with some anti-sieze which I forgot to do when I assembled. I never had to do this on other brake jobs but the book suggested it.



The temporary hard pedal I have had before. It is typically a low RPM's. I am assuming that the power steering pump is just not putting out a lot. It got a little better when I changed to synth fluid. This has been different. This was at a significant higher RPM and was not associated with a slightly harder steering that I normally get with it.



Things were better after I worked on it on Saturday. Same today going to work. I will keep a close watch on things for the next few weeks.



Thanks!