Brakes locked up, need help diagnosing the problem FAST

[Lonesome7.3]

I just put a new hydroboost on out 96 F250. I did the same conversion to our 95 F350 with no problems. I installed everything yesterday and test drove the heck out of it last night. Everything worked great. I drove less then five miles today and started having problems as I idled through a parking lot the brakes began to engage on their on. I got on the road thinking it might clear up but the opposite happened. The grabbed full force and stopped me cold. I opened the hood and power steering fluid is everywhere. There does not appear to be any ruptures and everything is intact. The fluid appeared to blow out of the top of the power steering unit. What should I be looking for and how do I correct it? I have got to get this done today!

 

[bigtex]

Did you bleed the system? If you did, did you pump the brakes while turning the steering wheel from left to right at the same time? With hydro boost, power steering and the brakes are now tied together. With vacuum, steering wheel turnage while bleeding brakes is not needed.

 

[Lonesome7.3]

I did. But get this, the brakes let go after sitting in my driveway for a while. Why is that?

 

[bigtex]

Define "let go" Like not engaging?

 

[Lonesome7.3]

The completely locked up. A tow truck brought it home, then some time while I was out getting parts the brakes let go. I was able to back out of the driveway and drive it down the street. I did nto go far becuase I did not want to take a chance.

 

[bigtex]

There's got to be a valve sticking somewhere, the only one that comes to mind it the proportioning valve for the rear. Possible cause: too much pressure on old equipment. Ya never know.

 

[towcat]

without knowing if you used the correct f450 reservoir or not, my guess is you have too much pressure in the return hose.

 

[Lonesome7.3]

Why and how do I fix it?

 

[towcat]

Why and how do I fix it?

where is the return hose for the hydro hooked up to?
if you used a f450 res. the nipple is up top and provides no backpressure to the hydro. backpressure to the hydro causes the system to energize.

 

[Lonesome7.3]

I have a T on the return line. I have done this mod many times in the past and this is the first time I have had these problems.

 

[Lonesome7.3]

Update:

Okay, so I brought this on my self. I wanted to use pats I already had on the shelf and they did not work. The rod was too long and it was keeping pressure on my master cylinder once everything got heated up. So, I went ahead and installed a new store bought hydroboost that is intended for my body style. After a good test drive the brakes did not lock up. Now I have the opposite problem… The brakes will not grab like they should and the pedal will not return all the way. I bled the system more than once. SO now what am I to do?