another power steer pump question

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tasvalowna

tasvalowna

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Hi , im running an 07 truck 5.7 in a hotrod with a ford power steer rack.
the ram pump runs at 1700 psi and the rack needs 1000 psi.
Ive disassembled the pump and found nothing is adjustable .
Surely there must be a way to reduce the working pressure and or flow?
These type 2 pumps are similar to the GM item but are they actually the same?
Any help appreciated
Ben
 
There are adjustable valves available, but I don't remember the brand name. I would think you could google it. Actually, I think I may have bought mine from Reilly motor sports. I think Bill carries them
 
Since a power steering pump is a pump, it follows the "pump laws." And the output pressure varies as the square of the of the ratio of the pump speed. So I would suggest changing the pulley size on the pump. So doing the math, the square root of (1700/1000) = 1.3. So if you increase the pump pulley (belt) diameter by a factor of 1.3, a pump previously putting out 1700 psi will now put out 1000 psi.

But remember, the diameter for calculation purposes, needs to be measured to the outer edge of where the belt rides in the pulley, not the pulley diameter. This should get you pretty close. Have I totally confused you?
 
I had thought of slowing the pump down , then wasnt at all sure how to get hold of a polygroove pulley the right diameter and the right offset.....
maybe i can just run a pressure limiting valve set at 1000 and dump the rest back into the return line?
 
These are positive displacements pumps and output pressure is established by the relief valve setting. Increases in pump speed increases the volume of fluid pumped, but the pressre stays essentially at the rv setting. You need to get a shim kit to lower the pressure setting in the rv.
 
th
RealWing said:
These are positive displacements pumps and output pressure is established by the relief valve setting. Increases in pump speed increases the volume of fluid pumped, but the pressre stays essentially at the rv setting. You need to get a shim kit to lower the pressure setting in the rv.
Click to expand...
This^^^^ not sure which pump you have exactly but the old trick was to put the relief valve from a slant 6 pump in the v8 pump dropping the pressure to something like 850 I believe , lower pressures create a " firmer feel " or you can research the shim pack method and make a shim for the valve that gives you the desired feel .
 
Cuda SRT8 said:
There are adjustable valves available, but I don't remember the brand name. I would think you could google it. Actually, I think I may have bought mine from Reilly motor sports. I think Bill carries them
Click to expand...
Heidts is the brand of the valve I use for this. It is adjustable so you can set the pressure you want. Available from Summit Racing or direct from Heidts.com
 
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