Sometimes when I apply the brakes the pedal is very hard and then all of a sudden the assist seems to kick in or it breaks free and I have brakes. The problem is is wont do it all the time, it did it quiet awile ago and then never did for about a month then started doing it again. I changed the brake fluid and I changed the hydraulic fluid and it didnt seem to help. Any thoughts on this would be helpful.


Thanks


Jason


2001 Quadcab 4x4

 

My guess is a sticky valve in the hydroboost. Unfortunately I don't have a testing procedure to prove it.

Chris

 

Check the vacuum lines, or booster may be going bad. I think it would be constant if the booster was bad. If you here a hiss at the pedal, this is a sign the booster is the problem too.

 

I have had and still do the same problem with my 2001. That funny feeling break pedal, at times you have to push really hard to stop and others just a light touch will do.

My house is the only one on the street, it is on a hill, I have to apply the break to stop at the bottom of the same hill with the same truck every day, one would think I would know how much pressure to apply.

At first I thought it was just my imagination in the feel of how hard I put on the breaks. But now I do believe it is a problem, this has been going on and off for about a year, but it could have only happened about one or two dozen times out of about 500 or so.

I did find out once if I start the truck shut the key off and then turn it right back on it will do it almost all the time. It will not power assist the break pedal, but while I drive after about 10 to 15 minuets when I use the break it works just fine and it will stay working, this only happens at start up. OverFueled

 

Anything else on this? I put the 1 ton rear wheel cylinders in and when the boost "kicks" in the rear wheels lock up. Not consistant either, usually after the truck sits for a while.

 

Under where the return line connects to the pump is a screen that could be clogged up that would cause this but you would lose power steering at the same time the brakes act up. If not suspect the hydo-boost unit. Someone posted here a few days ago about picking up a rebuilt unit for around $50.