okay so ive been chasing this issue for about 3 weeks now, and its getting very frustrating. after I come to a complete stop between 5-8 times the brakes seize up and my pedal does not move at all, ive replaced one caliper (bout 5 weeks ago by firestone) due to it leaking, the past 2 weeks ive replaced the other 3 wheels caliper slide pins and one caliper bracket. 2 of the wheels one front and one back were sticking pretty bad so they got replaced, and i replace the other one just for good measure. MY BRAKES ARE STILL DOING THIS!! i guess the next thing to do is bleed the brakes to make sure theres no air in the lines. But what else could be causing this???? i am completely stumped on this one and need some help.

thanks,
Mitch

 

If the rubber hoses de-laminates inside, the inner layer could stop the release flow (back flow) and still allow pressure flow. Bad hoses?

Just a thought.

 

Not sure what the problem is but it's not sticking calipers. When the slide pins or caliper stick...the pedal still works as normal, in fact, the driver might not even realize there is a problem unless the brakes are inspected.

If your brake pedal is sticking, then you might want to look at the pivot assembly or possibly a problem with your hydroboost.

 

I am thinking about hoses its been in the back of my mind and maybe i just need to bite the bullet on those, but everything feels great for about the first 5 stops then you can feel the pedal get harder to push down and at the same time i can feel the truck has some resistance on it cause after about 3 stops after its started to get hard, i let off the brake and the truck stays there, instead of rolling forward, even if im slightly downhill. i can tell the brakes are locked up because typically my boost at 35 mph is 0-1 and when the brake pedal is really hard its between 2-4 and my egt's are higher than normal.

this really has me stumped.

 

okay so im going to be replacing my hydroboost tomorrow and it looks simple to get out but my question is after i get it back in, do i have to flush the Power steering system?

 

Don't know if these systems have a proportioning vale in them and even if they do if that could be the problem. Had a Bronco that had a problem with it but just the opposite. First shot of the brakes and you kiss the windshield, after that it felt like only half the system was working.

 

I didn't flush mine... but I was a newb when I did it. Enough fluid drained that I just put in Mercon V.

 

well i replaced the PS pump about 6 months ago and did a full flush so the fluid is still really fresh, also when taking the master cylinder off, do i have to bleed anything?

 

You have to bleed the hydrobooster. If you don't remove the master cylinder, you don't need to bleed it. You should be able to reposition it without removing it.
The PS pump provides the pressurized fluid to both the brakes and the PS system equally (no check valve). You do not need to bleed the PS system if you don't let it get empty (its' components are lower than the hydro system). Just don't start the engine until you are done with the Hydro, and make sure you refill the PS before you do.

Follow the instructions, and you will not hove to bleed the PS system.

 

alright got it in and havent bled anything yet and my brake pedal goes down and wont come back up. do i bleed the brakes or the hydroboost? or both?

 

also the new hydro did not come with a rod that goes into the master cylinder...do i need that rod?

 

Never did one but I would say yes. It should go back the way you took it out, rod and all!

 

alright got the rod from the old part and put the m/c back on and everything worked great!! no more sticking did 5 test stops from 60-0 and the truck stopped better than it ever has and the best part was my brakes didnt stick after. (you actually dont NEED to bleed it, ill post up a video of what i watched to see how to do it and the mechanic in it will explain why)
over all the job wasnt bad wouldve taken me about 3 hr. if i didnt have to troubleshoot for almost 2 hr. before i realized what was wrong.

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thats the new part installed w/o the master cylinder in there.

 

Glad it worked out. Thanks for posting the video.

 

no problem! i would like to add if you get a reman, it wont come with the new pin that goes into the m/c you have to use the old pin, spring and spring retainer from the original hdryoboost. (i shouldve taken a pic. of that before i took the core in.)