Hydro Boost

I was wondering if any one can give me some input on a 1975 C30 that used to be an ambulance and then converted to a dump bed. It has a 454 and is an automatic truck with a hydro boost system. I drug it out of a fence row and got it running and used it for a whole summer, but I notice that it kept pushing steering fluid out of the top of the power steering pump. I changed the power steering pump and reservoir and did all of the bleeding steps that I have done on a lot of these trucks in the past and it is still pushing fluid out of the pump reservoir. I pulled the hydro boost off and sent off to a place that does rebuilds on them and reinstalled it and still have the same problem. I changed both hoses thinking that maybe the hose was collapsing inside and causing this issue. I'm open to any suggestions.

You said you replaced both hoses? Was that both the pressure hoses? Have you checked the spitter valve hose on top of the unit? The return lines? The pump could be going bad. The great thing about Hydro boost is... it is a pretty simple system.

PS pump cavitation can cause air to be introduced into the fluid. When vehicle is shut off the air expands, pushes fluid out of the reservoir. In other words pump could be bad.

I did not replace the return line.
Do you think they would have had a heavy-duty power steering pump originally with it being an old ambulance? Napa just showed a 1 pump for the 454

10 Squares said:

I did not replace the return line.
Do you think they would have had a heavy-duty power steering pump originally with it being an old ambulance? Napa just showed a 1 pump for the 454

Click to expand...

no

Rebuild your pump as quality of new parts went south.
Lots of information and videos on rebuilds.

https://www.classicwinnebagos.com/forum/index.php?topic=16885.0

My 1987 V3500 is currently at the body shop. I trying to remember if there is a cooler for the P/S system. I would check every hose and if there is a cooler make sure it is clear. Inspect all metal lines and make sure none are crushed or kinked.

You did not say if the system worked or not. If it works you have to have some flow.

ali_c20 said:

Rebuild your pump as quality of new parts went south.
Lots of information and videos on rebuilds.

https://www.classicwinnebagos.com/forum/index.php?topic=16885.0

Click to expand...

Agree parts are poor quality. However, last time I looked into rebuilding a PS pump internal parts were beyond expensive.

Welcome to the forum

Might want to check to see if your system was equiped with a filter in the power steering system. Mine did the same thing after replacing the steering gear. Looked it up on all data and found out it. When you bleed the system the engine should not be allowed to run, just pull the couple wire and crank on it.