Lesson with steering pumps and reservoir

496BBC

496BBC

Well-known member
Joined
May 13, 2008
Messages
210
Location
Deep in the marsh, South Louisiana
I learned an important lesson while working on my car and the steering system.

I installed a hydro boost on my car a while back and have been experiencing issues with it. When I would hit the brakes and turn the steering would lock up for a spit second. This has always bothered me and I have been trying to resolve this issue for a little while now.

I had been putting off tearing down the steering system for a while but I knew it would need to be done sooner of latter. I blew a steering hose so I had to work on the system anyway so I decided to tackle the steering issue while I was working on it.

I spent a good bit of time researching any info I could find on the internet and was able to narrow it down to 1 of three possible causes.

1) Air in the system
2) Hose leak on the suction side
3) Not enough flow from the pump

I found a post by Jim82, I think this is Jim Shea the one that helps with all the steering issues on the different forums. He indicated that if you turn rather quickly and the steering gets hard and than easy again than its probably not enough flow. I was able to pull the flow fitting and enlarge the orifice and increase the flow but this caused my problem to get worse. The one thing I noticed was the pump would wine anytime I hit the brakes or turned the wheel after I enlarged the orifice.

I called Zoops to find out if they may have any ideas on what may be causing my issue. They had indicated that the pump I had was a low flow pump for use with a Ford rack and pinion setup. I asked if they could send me the correct fitting and they said no but if I wanted to send them my pump they would change it for me at the cost of the fitting and shipping. I didn’t want to send my pump so I decided to increase the flow myself by enlarging the orifice.

I decided to tear the pump down and take a look at the pressure setting. The Ford rack is setup to work with around 800 psi, 2 gpm and the Hydro-boost and chevy rack and pinion is setup to work with around 1200 psi and 3 gpm.

I use a pump to remove the steering fluid so I don’t make a big mess while removing the hoses from the pump. When I removed the fluid I notice the diverter fitting on the return side in the remote reservoir had turned and was diverting fluid straight to the inlet of the pump. This caught my attention so I reached in and turned the fitting (Tee) so that it would divert the fluid away from the inlet of the pump. This appears to have taken care of the pump wine and the steering is consistent with no hard spots and the brakes work fine. I’m sure the increase in flow has resolved my hard steering while braking issues and the Tee fitting was my issue with the pump wine. I think the fitting was feeding the pump with turbulent and air-rated fluid causing it to wine.

Neal
 
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I dunno man, dumb luck? but I just put a 3/8 T in the return lines....even fed it rong according to some posts...the pump to one of the arms, the base fed by the rack the HB in the other arm.....works fine....same thing with the Motor Home project....

:smash::surrender:
 
For a discussion about PS pumps and how to plumb them for the hydrobeast, search for the thread by denpo on 01-29-2011. Jim82 discusses how to plumb for the hydroboost return line.

Also, as a result of that thread, I bought a Saginaw PS pump, 88985365, for $80 from RockAuto. It's a pump sold on GM trucks that had a hydroboost as standard equipment.
 
Most people think that a pump reservoir (either integral to the pump or remote) is just a holding tank for additional power steering fluid to compensate for fluid expansion with temperature.

The reservoir actually performs another important function. It allows air to seperate out from the fluid and rise to the surface of the fluid in the reservoir. This means that the design of the reservoir and the location of the spout coming back into the reservoir are all very important. Also, some reservoirs have baffle plates, screens, extra chambers, etc so that the returning fluid has a chance to let air escape. The worst thing would be for the returning fluid to enter the reservoir and then travel directly into the pump intake. The air in the fluid would then multiply with each circuit of the oil.

Saginaw actually designed their reservoirs by making prototypes from clear plastic and visually noting how the returning oil acted under operating conditions. These same prototypes were also tested at -40 F to see how the thick, cold oil acted in the reservoir.

I can tell you that all Saginaw designed reservoirs (i.e. integral sheet metal, remote plastic, remote sheet metal, integral plastic, etc) were all designed and tested as noted above. Unfortunately, I would guess that most aftermarket reservoir designs were never fully tested as above.

Jim
 
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