Hi, I tried a search but it did not work properly tonight. Does anyone know an approximate pressure that the 5.3 truck power steering pump or even an ls1 pump put out? I have a custom 1950 chevy truck with a Mustang II IFS with power rack and pinion steering and I connected the lines properly tonight and tested the steering. It worked beautifully, but tried to blow out the seal (just leaked some) around the steering shaft into the rack and pinion. The ford pump uses about 600# line pressure. Thanks

 

About 1300psi I believe. Heidt's makes an adjustable valve that can be used to tame a GM pump to work with a Ford rack.

 

I really don't think the newer Type II power steering pumps put out 1300psi. I think you may be referring to the old box-style PS pump.

The new style pump I believe is about 900 or less. It usually works very well with a Mustang rack, so I'm not sure where your problem is (mine works great too). If you need to know a number, contact Detroit Speed and Engineering.

 

I've always heard that the LS1 pumps run at 1200psi. No idea if that is correct though. There is a long ongoing debate in the RX7 community about the proper way to lower the pressure down to the 900psi that our racks are designed for. Most simply trim a few coils from the bypass spring that is inside the high-pressure side fitting.

 

You can tweak the spring to get it down close to 900psi, but I don't think it's there stock. The RX7 guys seem to have problems with the LS1 pump and have to reduce the flow/pressure.