Power steering pump mod in a Nissan Hardbody D21 and Pathfinder WD21

updated 10/6/2011

The 93 and older rigs seem to have less POWER in the power steering than the 94+ rigs. King and Ben have found ways to modify the pump to increase flow and pressure. This mod just needs some drill bits and basic tools and a washer or small nut. The pump does NOT need to come off engine for this modification. This was done just for demonstration.

The modifications include the following:

  1. Add a spacer under flow valve spring to increase pressure.

  2. Enlarge hole in flow valve

  3. Enlarge hole in connector inlet

  4. Enlarge hole in connector outlet

First remove the High pressure hose at the pump. Large 24mm nut. Then unscrew the "connector", then remove the flow valve with a magnet tool. The spring does NOT need to be removed from pump.


You can see Nissan increased the flow increase in 94 connector. Note the larger output hole.

The flow valve is a piston that controls flow. I use some Dikes to remove end cap. I grabbed end with dikes and hit dikes with a hammer. Its a press fit.

I added a 3mm nut under spring. This increased the pressure at idle. WARNING I did cause my old hoses to start leaking shortly after this modification. I replaced the high pressure hose with a lifetime replacement one from Autozone and Oreilys. My 92 and 93 started leaking at the rubber part after the pump.

I also enlarged the hole in the flow valve. You have to disassemble by removing the pin. I had to use masonry bits. I burned up a few high steel bits first.

This is the parts breakdown for the 90-93 style pump. 94 is identical to my eyes. Only the enlarged holes are different.

The pump apart. Very nicely made. All steel parts and gaskets and a few o rings.

Update. I ended up burning up the idle circuit on 2 pumps. For some reason I lost power steering at idle but works great above idle. So I decided to install the w/d21 aluminum style pumps and are very happy with those. See more here: