2nd Gen Non-Engine/Transmission ABS & BRAKE LIGHT ON

[Herman8r]

I just did a search on"hydroboost" & found this site http://www.hydroboost.com/.



It described my problem--at least one of them.



It just all seems too coincedental--this started after I pressure bled the system!!



Herman

 

[DieselDoghouse]

Well, hope I helped - I only brought this up b/c after I had to replace Mr. Hydro(a leak) I found I had less rear tire spin at a green light - my fronts were dragging ever so slightly. Why didn't the back? maybe the difference between disc and drum in terms of grip and brake travel. Just wish the hydroboosts were testable by the regular guy. I can reconfigure a tractor hydraulic valve in the barn but we can't test these to see if spools, valves, and springs are hanging up. BTW - have you ever found your hydroboost to get REALLY HOT when you park the truck. That was one of my tip-offs. After a search here, I added the cooler to the P/S circuit - the older trucks had 'em!!!

 

[Herman8r]

I have not noticed the HB getting hot--although I have not checked it. Will do so in the am. The is a local brake builder in the area that I have known for years. He said he will test the HB -- no problem. He said the easy test is to pump the brakes (engine off) about 5 or six times --depress the pedal hard--start the engine--the pedal should have a slight drift downward & then rapidly spring back. I did this test & mine does not spring back. It stays in one place--down.



Also - I did a little testing today. I slighty pushed down on the E braked while driving forward & then pumped the brakes while in motion. The "dragging "effect seem to get worse. I beleave the rear brakes are dragging as well but the result is not noticed as much.



Tomarrow will be another story

 

[Herman8r]

Just had the hydro boost rebuilt. The tech said it was full os sluge & the seals were hard & ready to blow. Installed the HB & no change. The calipers still hang up during stop & go traffic. I am at a loss here. What else can it be???



Help !!!

Herman

 

[Willys]

(This is just a shadetree opinion/idea... FWIW)



When you were working on the calipers, did you ever force the piston in? It could have cocked it sideways a little, making it stick. I doubt it would have happened on both, unless they were forced in exactly the same way.



I hate that you've spent so much on parts and still can't find the problem. I know how frustrating things like this can be...



Andy

 

[Herman8r]

Hi Andy--I changed the whole caliper & pad assembly as a new unit so there was no reason to depress the piston.



Thanks for the thoughts.



I was wondering if the ABS system could some how affect this--as this situation (sticky calipers) started after I 'pressure' bled the system.



Herman