Power Steering Mystery

[Benannah]

Hey all, I’ve been working on my power steering for a while and it is driving me nuts! I just replaced the old pump with a reman as the old one was badly worn. Shortly after replacing, it seemed to work alright, but within a few minutes of driving, the power steering was entirely ineffective. I checked and there are no leaks, and the pump is indeed pumping fluid. What could be the problem????? I’m totally stumped!

 

Happy Holidays!

[datzenmike]

Did you bleed the hydraulic system? properly.

 

Raise the wheels off the ground. Start engine and quickly turn full left and right quickly and turn off engine to reduce foaming. Check fluid level and fill if needed. Repeat till no fluid needed.

 

If reservoir is full of foam let sit over night first.

[Benannah]

I did not ever raise the wheels off the ground, but I did turn the wheel from lock to lock many times and drove it around for maybe half an hour. The steering only seemed to get worse until it got to the current point where the power steering effectively does nothing

[datzenmike]

Did you check the reservoir. If not bled of air, driving around will foam the oil and foam, like air in the brake lines, is compressible. Raising allows speedy lock to lock.

 

Let it sit and check in the morning.

[Benannah]

I’ll let it sit overnight, but the fluid looked perfectly free of any bubbles. I also put the return line in the fill cap to watch the fluid flow and everything seemed normal with no air

[datzenmike]

There may be flow but no pressure. There is a pressure relief valve to set the maximum pressure. Just like the oil pump it opens and recirculates excess oil to maintain the pressure set by the spring inside. If it were to be stuck slightly open????

[Benannah]

Okay, that seems like something worth looking into! Where would that be and how could I easily adjust that? Also, would that explain the issue of the pump working for a little bit and then stopping working? The old pump would never build up any substantial pressure so this is the first time in several years that the system has seen this much pressure

[datzenmike]

Two pumps with pressure problems is unlikely to happen and would indicate the problem is elsewhere.

[Benannah]

Kinda what I’m thinking. Especially since the pump seemed to work perfectly for a minute or so and sounds pretty quiet.

 

With that being said, what else could it be? I heard that it’s possible for something like a seal to fail in the steering gearbox? Any ideas?

[ElliotV]

27 minutes ago, Benannah said:

Kinda what I’m thinking. Especially since the pump seemed to work perfectly for a minute or so and sounds pretty quiet.

 

With that being said, what else could it be? I heard that it’s possible for something like a seal to fail in the steering gearbox? Any ideas?

The steering box will have seals on the shafts for pressure it is possible that the new pump finished off the 40 year old seals and now it wont build pressure

[Benannah]

Yeah, I’m worrying that may be the issue… is it reasonable to replace just the seals or am I looking at a new steering box? If a steering box will fix the issue for sure, I’m more than willing to do so, but would rather not spend that kind of money if I’m not sure it will fix it.

[ElliotV]

2 minutes ago, Benannah said:

Yeah, I’m worrying that may be the issue… is it reasonable to replace just the seals or am I looking at a new steering box? If a steering box will fix the issue for sure, I’m more than willing to do so, but would rather not spend that kind of money if I’m not sure it will fix it.

you can order a rebuild kit for a first gen nissan pathfinder which appears to have the same box from what I could find and then rebuild your current one or just fork out the 300 bucks for a reman

[Thomas Perkins]

Steering rack problems:

A worn or damaged steering rack (gearbox) can affect fluid pressure and steering response

[ElliotV]

I might be wrong on that though because I just looked again and the d21 box has 4 bolts while the 720 appears to have 3. I am not at home so I am unable to compare properly.

[Thomas Perkins]

Steering rack problems:

A worn or damaged steering rack (gearbox) can affect fluid pressure and steering response.For your 83

[Thomas Perkins]

Nissan has a seal kit.for 26.98.Here is the Nissan.part number.Nissan 49202-01C25 Seal Oil Sector

1983-1986 Nissan 720 Pickup 4920201C25.Easy to do.Look at the picture and you will see where the seals go at the bottom of shaft.Also go look at it and see if it is leaking there.It is also showing other seals too.

Edited December 25, 2024 by Thomas Perkins

[Benannah]

Good to know, where would I find that and how hard would it be to replace?

[datzenmike]

What does the seal do???? If holding pressure in and it lets it out where does it go???? If leaking where's the fluid leaking to??? Not on the ground or you'd see it.

[Benannah]

That’s my concern with this. I’m very sure there are no major leaks as I drove it for half an hour with no drips. I know there is a valve in the steering box though? Maybe that? Otherwise how hard would it be to test the pump pressure release valve?

[datzenmike]

Pump

 

You can put a pressure gauge on the pressure side between pump and steering box. Run engine at idle and turn steering all the way to one side til it refuses to turn further and get a reading. Idle pressure should be 1,200 to 1,200 PSI from the pump. You must do this quickly and get a reading to prevent over heating or damage to the pump.

 

 

Power Steering

 

Any replacement of parts requires the box be dismantled so I hope it's pump pressure as I have never taken one apart.

 

 

 

[ElliotV]

7 hours ago, datzenmike said:

Pump

 

You can put a pressure gauge on the pressure side between pump and steering box. Run engine at idle and turn steering all the way to one side til it refuses to turn further and get a reading. Idle pressure should be 1,200 to 1,200 PSI from the pump. You must do this quickly and get a reading to prevent over heating or damage to the pump.

 

 

Power Steering

 

Any replacement of parts requires the box be dismantled so I hope it's pump pressure as I have never taken one apart.

 

 

 

from what I have found that style of box isnt too bad to take apart but I still havent had the chance to take one apart you just have to keep track of your balls

[datzenmike]

The actual steering box has recirculating balls but the power unit does not I think. My manuals do not break this unit down.

[Benannah]

So uhhh… I drove it to family this morning and it still didn’t work right. Then I parked it for about 4 hours and then drove to other family. On the second drive, the ps worked perfectly and had been very good on a couple other rides today. Maybe air in the line, maybe a stuck valve, but I’m just going to accept it as a Christmas miracle 😂

 

Merry Christmas and happy holidays!

[datzenmike]

If air trapped, was released, the reservoir will be down slightly.

[Benannah]

The fluid did seem to be down ever so slightly, so I’m guessing that’s the issue. Guess I’ll remember the importance of a proper flush next time! Thank you all for the help!!!