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I have a medium duty 12V that has a LUK power steering pump. I think this pump is too powerful for my F250's hydroboost. My P.S. fluid it very burnt LOOKING/smelling. I have read that I need to get my hydroboost bypass valve teamed out. Does anyone know of a place that can do this work? I would like a place in San ANTONIO/AUSTIN AREA. But at this point I will ship it some place to get the work done.

Thanks
 

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does anyone know what the stock Ford PS pump puts out for pressure? I have a LUK PS pump with 163 BAR and the pressure says 14 I assume it is 14,000.
Thanks
 

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does anyone know what the stock Ford PS pump puts out for pressure? I have a LUK PS pump with 163 BAR and the pressure says 14 I assume it is 14,000.
Thanks
163BAR equals 2364.115 psi. I had my LUK pump reset at a local hydraulic shop that specializes in truck power steering boxes. cost me $45 to add the right shims and test for max pressure and flow(gpm). my pump stock had 2250 psi and 4.25 gpm. the pressure valve looks exactly like the one in a GM saginaw pump. you can do it your self, pull the valve out of the LUK pump, unscrew the hex ( it has a small screen in it) on the end of the valve and add 2 or3 shims along with the shims already there (if any)(he took the shims out of an old saginaw pump) ,do not loose the small ball or spring. reinstall the valve and test the pressure, I think he used 3 shims on my pump. it tested at 1650 psi. and 4.25 gpm. saginaw gear boxes and hydroboost can use up to 1800 psi. I talked to LEE Powersteering in LA. they build nascar gear boxes , pumps, and high performance off road stuff, and that`s what they told me . 1800 is max but set it to 1650 or so. put a "T" in the out let of the pump and put a high pressure gauge ( high side from an oxygen welding regulator) and with the engine running, turn the steering wheel all the way to right or left and read the pressure gauge. do not hold the wheel too long, 2 or 3 seconds will give max pressure on the gauge. after I saw how he did it, I know how to adjust the pressure in any saginaw or LUK pump. hope this helps capable people to adjust their own pumps. add shims to LOWER pressure, REMOVE shims to raise psi. changing the pressure will not change flow (gpm) LEE told me hydroboost systems can use up to 4.5 gpm. :) :) most stock pumps put out about 1200 psi more ore less
 

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Discussion Starter #4
Thanks a million.
I have tried to get ahold of lee but I have not had the time to try again.
I might just give it a go and try to diy it. I figure if I can put a cummins in this thing your write up sounds fairly simple.

Thanks again.
 

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Discussion Starter #6
Just an update. I took the PS pump off and removed the 1" IIRC cap and pulled the valve out. Added 3 shims to it and reassembled it. It was a piece of cake to do. I can even remove the valve without removing the pump. All seems to be working well.

Thanks again jtamulonis
 

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Just an update. I took the PS pump off and removed the 1" IIRC cap and pulled the valve out. Added 3 shims to it and reassembled it. It was a piece of cake to do. I can even remove the valve without removing the pump. All seems to be working well.

Thanks again jtamulonis
I`m glad you got your problem fixed, cheaply. that`s why I LIKE this forum ! we pass information back and forth for the benefit of the members. any one else can raise or lower the pressure on their saginaw or LUK power steering pump easily, and usually without removeing the pump from the engine. you`ve learned a new skill, and maybe others here will be encouraged to try this fix too. :beer: :beer: :beer:
 

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Discussion Starter #8
now that I have been driving the truck it still not right. the pump still groans and whines a lot now that I am taking the truck off the pavement it really makes noises when the road pushes the wheels left to right. It is the loudest thing I hear inside the truck. So I added a few more shims and it still does not feel or sound right the steering is better but the brakes feel funny I can feel it pulsating. Hopefully it is just air that needs to be bled out, but I don't know.
 

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now that I have been driving the truck it still not right. the pump still groans and whines a lot now that I am taking the truck off the pavement it really makes noises when the road pushes the wheels left to right. It is the loudest thing I hear inside the truck. So I added a few more shims and it still does not feel or sound right the steering is better but the brakes feel funny I can feel it pulsating. Hopefully it is just air that needs to be bled out, but I don't know.
Do you have seperate returns to the reservoir? Hydroboost units don't like backpressure. If you tee the returns from the box and hydroboost they act like you describe.
 

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Discussion Starter #10
I have the typical 2004 Ford F250 hydroboost set up but just with a LUK pump, no Tees. I think I am going to try adding more shims and see where that gets me. The first time I added a fairly thick shim so I removed a few of the existing shims (I was not thinking) the few more shims I just added were the ones that were on the pump to beguin with. I think I just need add a few more the pump is at 2350 psi and I need to bring it down to 1600 psi or so. It really is simple to add remove shims on this pump I can do it in about 5 minutes.

Thanks for your input.
 

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Oh yeah I added a cooler to it, the factory ford cooler was MIA when I bought the truck as I was doing the swap I added a cooler to it. It was a small tranny cooler, a double pass cooler. But that should only help things.
 

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Discussion Starter #14
another update.

After a little trial and error I got the problem worked out. It just needed one more shim I added 2 and I couldn't turn the wheels without rolling, so I removed a shim and we are in business. After the shimming was done I proptly took it to get my inspection. It is now legal.

Now to start driving it and tie up the loose ends.bounce
 

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did you ever figure out where the shims/washers go? i have the same valve set up
the shims go on the valve in the lower picture. when you put shims between the valve body and the cap screw with a screen in it, it lowers the spring and oil pressure inside the valve. removing the shims increases the spring pressure and oil pressure.
 

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I run two (2) p/s hydro coolers two (2) filters in hydro return lines & synthetic P/S fluid on a 1.5k psi setup and avoid higher pressures if I can.
 
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