Power Steering Problem

[Darius]

Symptomes: I have an RB25 swapped into an S14 and I have minimal power assist. Fluid in the reservoir barely moves whereas before it was a vortex of fluid. There is no squealing from the pump, no belt slipping, no air bubbles or foam, no leaks, and the rack does not make noise when turned all the way in either direction. The last symptom makes me wonder if something is wrong because it used to make noise at full turn either direction and now it does not.

I just disassembled/reassembled the RB25 pump. I had a small leak and thought air was getting into the pump and either air-locking it or preventing it from pressurizing the AT fluid. But no air shows up in the reservoir when the engine is running and the pump is theoretically pumping.

For a little background, I used to have working power steering with the swap. At that point I changed out the high pressure line for a teflon braided SS line. During turbo/manifold modifications, I relocated my PS reservoir to the radiator support and installed -AN fittings and SS lines. In order to do this, I tapped the PS pump inlet opening. The first pump I drilled out too wide and poked into the high pressure side of the pump. So I bought a different used pump and assembly has worked well.

Can anyone offer some insight as to whether this is a pump or rack problem?

[kouki munster]

If I remember correctly there is a pressure regulator valve in the pump, it may have s*** the bed, causing the system to not build full pressure, and thus causing the hard steering. Other than that check all the hard lines to make sure that they are not kinked.(the ones on the back of the rack under the engine especially)

It is a lot easier to replace the pump than the rack, so I would start with the pump.

[Darius]

OOH good point. I completely forgot that was inside the discharge of the pump. Does anybody know how to get that thing out of the pump? I couldn't figure it out by looking at it so I figured, meh, it'll be alright. The rest of the pump looked fine and none of the lines are kinked (kinda hard to do to ss lines), so I'm guessing it is either the rack or this valve you're talking about. Thanks for the help kouki munster!

[mixeds14]

man, i having the same symptoms/problems as u.. i think its the pump though.... im thinking i might just switch over to the ka pump n be done with it.. i read somewhere on here that the s13 dohc pump is the one that works with the rb but u have to modified the brackets or something, i goin to look for that tread again but will see how it goes..

[Darius]

If I remember correctly, the S14 pump works directly with the RB25. If you have an RB20, you need to get different brackets, etc. I'd double check that in the RB forum search though.

[Darius]

I pulled the flow control valve and there are a couple things that I noticed abou it. First, the screen on the inlet to the valve housing is very fine and appeared to be clogged? I dunno for sure because nothing really came off of it. Second, I noticed that there were polished-looking wear areas along the outside of the body where it appeared that fluid had been flowing past the flow control valve. I'm not exactly sure how this thing works, but here are some pics of it removed.

The flow control valve is the weird looking thing with the screen on it. It goes into the pump screen first. Then the fitting with the 2 holes in the bottom threads into the pump housing and the -AN adpater fitting threads into that with an o-ring (broken in this pic)






My questions are:
1) If I removed the flow control valve assembly (assuming it is bad), will the system still be able to pressurize the rack and provide power assist? Or will the pressure simply bleed off into the suction side of the pump and not create pressure?

2) Would replacing the flow control valve with something like this be a solution?? I am calling this shop on Monday to get their tech advice.
http://www.krcpower.com/flowvalves.html