Power steering problem

[Pax84]

So I’ve been fighting with my power steering for about 2 and half weeks now. I have looked up and researched all different ways to bleed it and still nothing. My issue is the lack of any power steering, I get no assist when I steer the wheel. I had bought a brand new Saginaw pump from BC Broncos because I have their serpentine kit and I also bought a brand new (said new) 2wd F100 steering box from Bronco Graveyard because it was what I had already and figured just unbolt the old and bolt up the new. Well I’ve hooked everything up and have no power steering. I’ve tried with the engine on and off and still get bubbles. I took of the return line to check if the pump was working and it shoots out fluid(and a lot of bubbles) so I’m guessing it’s working. I’ve got no leaks so if someone could help guide me in the right direction to get it going I would really appreciate it.

 

[DirtDonk]

You might have a wonky fitting that is somehow allowing air in but not showing a leak of liquid yet. Did you replace any fittings? Hoses?
Worth checking them all to make sure they are tight.

In all your reading have you found where it usually takes us a lot of repetitions before the air is all out?
I know most instructions say to turn the wheels back-and-forth three or four times, but over the years many of us have found that it can take up to 100 cycles!
Definitely lift the wheels off the ground however, or at least mostly so there is very little to no vehicle weight on the tires. And then just sit back, relax with a good book and turn that wheel back-and-forth without hitting the stops.
Do not hit or hold the system against the stops while you’re trying to bleed it. Just go back-and-forth almost to when it stops and then start over again.

Hopefully you haven’t done that already?

 

[Pax84]

I did have a small leak on the return line earlier in the week, tightened it down and no more leak, since then I’m not sure how much I turned it but I’ll get back to it after work. And should I have the engine on or off while I bleed the system? I’ve read both and I’m not sure what’s the correct (or better) way? Also I’ve have gone lock to lock, I didn’t hold it there but I did go till I started feeling resistance and then turned the other way. Is that bad or damaging in any way?

 

[DirtDonk]

I think the “while off” part is just in the beginning. You’re well beyond that now, so I would do all the rest with the engine running.

 

[DirtDonk]

As long as you don’t hold it on the stops you should be good. I don’t even remember what the reasons are, but I never push hard against the stops. And rarely even up to the stops once I know where they are for each vehicle.

 

[Pax84]

Well I’ve been at it for about 2 hours, no bubbles that I can see but still no power steering, is this a bad pump? Bad box?

 

[DirtDonk]

You said when you tested the pump it was flowing pretty good? I suppose it could flow good and not have much pressure. In that case you wouldn’t have much assist.
There’s also the chance that the pressure line is plugged a little bit I suppose. If it’s the same one as before that’s unlikely, but if it’s a replacement for the changed parts it’s a possibility.
I think if you had the lines reversed high pressure for low pressure, you would get some really weird funky reactions from the box.
I don’t think it would just be a simple is no power assist but if you want to verify, the high pressure from the pump goes to the port in the forward most position.

 

[Pax84]

The lines are in the correct spots, and I had popped the high pressure line off and it seemed to flow better than the return line did when I had it off. The lines are the same as before and they don’t seem to be plugged up. I still have no assist at all, the pump makes no noise but I’ve heard that’s a Saginaw thing.

 

[nvrstuk]

By a 1500# gauge and check the HP line.

Then in 15 minutes you can be 100% certain if it's box or pump. I've done this and it's worth it.

 

[Broncobowsher]

I'm leaning toward the pressure relief valve in the pump. It may not be in the pump. The new pump may be expecting you to use your old valve, that didn't get swapped in.

The pump will pump good volume, but any resistance and it will just recirculate. I know you don't have it, but for reference on how they can be touchy, Explorer pumps with a generic AN fitting that is a little too long are will known to press on the relief valve and you get no power steering. Neither the pump nor the box is bad, just the wrong adaptor fitting screwed into the pump.

Easier pump test than putting a pressure gauge on it. Just dead head it. The pump should moan like you are at full steering lock, the hose should get stiff from the pressure, and the pump should build heat really fast. That will show the pump and relief valve are working. If you look in the pump and see fluid circulating, the relief valve is open or missing.

 

[Pax84]

Well I ended up taking off the high pressure fitting and sure enough I did not have a pressure relief valve, so I’ll be getting one of those and I’ll let you know if it works. Thanks for everything so far hopefully this solves my problem.

 

[Tulsa76bronco]

Not to highjack but I too put on a new pump but have yet to turn it on should the saginaws come with a pressure relief valve? I bought my from CJ Pony where do I look for this in the pump still has the white cap on the back

 

[DirtDonk]

I think that’s a good hijack. Perfectly appropriate for this discussion.

 

[Yeller]

Not to highjack but I too put on a new pump but have yet to turn it on should the saginaws come with a pressure relief valve? I bought my from CJ Pony where do I look for this in the pump still has the white cap on the back

Post a pic of the area with a cap

 

[Pax84]

Should be behind the high pressure fitting where your high pressure line bolts into on the pump. Unbolt that and it should be behind there.

 

[Tulsa76bronco]

Here is a picture of the back with the white cap

 

[Yeller]

The relief valve is interenal, I would assume its in there unit you know its not, very unlikely that it is missing. Not saying impossible, things happen but highly unlikely.

 

[Tulsa76bronco]

Ok at least if I do have the issue Pax has I will know what it is

 

[Yeller]

And I probably have the parts to fix it laying around

 

[Tulsa76bronco]

Is this what I am looking for