Brake issue ?

[Joey0278]

My 97 k3500 started holding the front brakes like the hydraboost wasen't working right but wouldn't it hold all 4 instead of the fronts ? It has hard steering at times but it has a new ps pump so i think it needs a hyrdaboost ?

 

[stutaeng]

Wait, what do you mean, "holding the front brakes?" Does that mean not working or not what?

 

[454cid]

I'm trying to think what causes it.... there is a situation with the hydroboost where the brakes get activated automatically, or won't release. I'm thinking it might be if the return line doesn't work well enough..... some guys that Tee into the regular return line on a non-hydro pump have run into problems. I'm sure you probably have a hydroboost pump, but could you have a blocked line?

 

[TheAutumnWind]

Sticking calipers?

 

[thinger2]

It could be both calipers are sticking or both front brake lines are internally rotting.
But, since you are having steering and braking problems I'm gonna bet its hydroboost system related.
Is it leaking anyplace? Look at your power steering fluid after its warm and the has been turned a bunch of times.
If the fluid is all frothy full of bubbles, It's sucking air.
The system uses a valve to apply pressure from the ps pump to the brakes so if you get air in the pump, as soon as you hit the brakes that valve moves and can pump air or dirt ino the brake side of the system.
Any place fluid can leak out is a place for air and dirt to get in
If it's not sucking air, then the return is plugged or the rod in the master cylinder broke its bushings and is sitting in there wrong or the seals on the spool valve are wasted
Do you have ABS brakes?
On a non ABS you can check for air in the brakes by bleeding them but on ABS you need a dealer or a brake shop with a scanner to bleed them.
And, if you do have ABS did the light ever come on during any of this?
There are some ABS issues that can also cause a problem