Been rebuilding the front end on the 97 Dodge 2500 ...replaced the steering box and power steering pump today and filled the reservoir and started the engine and turned the wheel lock to lock to bleed the system ...all seemed well on my first test drive but about 6 miles down the road the brakes started acting funny and the steering had no assist at all.

I haven't had much experience with hydro boost but I'm kind of thinking that's about all that I haven't changed.

Any ideas or suggestions would be appreciated.

Thanks

 

You might have shook some particulates loose in the system. There's a valve in the hydroboost that can get stopped up and there goes your steering and brakes, then a little while later it gets flushed through and everything is good again. I had it happen once, thought I needed a hydroboost but after a very hairy drive back to the shop it was back to normal again. That was about 60K ago and it's never done it again. Not saying you don't need a hydroboost, just saying you might not.
Also, your hydroboost essentially uses two things to function, the hydraulic pressure from your steering pump and vacuum from the vac pump. I'd check the vacuum line from the pump to the hydroboost and make sure it's still connected at the test fitting. You can put a gauge on it and make sure it's pulling at least 20-22psi of vacuum at idle, but I don't really know what the symptoms would be if it wasn't or if lack of vacuum alone is enough to crash the system. It's far more likely a hydraulic issue. Any good shop should be able to put a gauge on the hydroboost and see if it's healthy, worst case a dealer can but in my experience they can't usually find their way out of a proverbial box with a map when it comes to these trucks.

 

Definitely check for vacuum leak. there is obviously a hose that runs to the booster that helps assist with braking etc. I know you changed it probably but check that out.

 

After an hour or two of bleeding the system finally got it done......thanks for your replies