I'm having a problem with the power steering pump- I'm running the pump for a 6BT on my 4BT. (I put the 4BT into a 92 F150 4x4).

This thing is driving me nuts. I was leaking fluid from the pitman arm shaft of the steering box, so I replaced the seal/washer. No leaking there now. I knew I was also leaking somewhere around the reservoir. Had my gal get in and turn lock to lock, numerous times, and I didn't see a drop except for some seepage around the cap. Anyway, second guessed myself and took high pressure line out and replaced the o-ring. Still no leak around the line, etc. BUT, when I get her out on the interstate, at sustained higher rpm's, it leaks badly. Bad enough to get down the framerail and blow to the rear axle. When I look, it seems to just be coming from the cap.

After some research, I'm thinking of taking the bypass valve, etc out of the reservoir and clean the screen off. Maybe I have a blockage, which is increasing pressure? I don't understand completely how these things work, but if the bypass valve was defective, then I might experience high pressure into the reservoir also? Anyone dealt with this first hand?

I've read every thread I can find on this forum (as well as a couple others) and cannot find a definitive answer. The pump seems fine - no whining (when it has oil), and the truck turns fine.

I'm at a loss. I run ATF, but I don't think that's the problem. Has anyone experienced this "blowing out the cap", and cured it simply by running a certain type of fluid? And keep in mind that it's substantial in my truck (not just a little drop or two). If so, please share your experience...

Does anyone know where to get the valve assembly for this unit? I might buy one if I had any idea where to get it. I won't be able to tell if the valve is bad or not, but I might just put a new one in if I could find one... Any ideas?

I've read that some guys cure the issue with replacing the steering box. I guess it can suck air through faulty seals. Like I said, I replaced the seal/washer on the main output shaft (pitman), and no leaks there anymore. I can't see any leaks from the input shaft (steering wheel), but maybe it's sucking air through that seal? I'm just kind of at a loss.

Anyway, sorry to be so long-winded, but this thing is seriously pissing me off. I've been messing with this on and off for several weeks, and still don't know what the culprit is. Everytime, I change something, etc, clean it up, take for a test drive, and bingo, it's covered in red ATF again! HELP! Thanks,

 

It's a hydraulic system, so there's no air sucking involved. The only air issue is if it gets air in it after some type of maintenance it can cause foaming and possibly the symptom you describe. Also, possibly internal cloggage like you describe. have somebody cycle the steering back and forth slowly while running with the fr wheels off the ground to try and work out any trapped air. If that's not the case you'll probably need to R&R the pump. You could try flushing it to clear it out while doing the above with some type solvent or solvent mix (diesel?), but that's risky to the seals. If the pump's fried it don't really matter then anyway.

 

Wasn't sure about the air thing, but that's what I've read. The good ole' internet...

The pump seems to be working fine, just puking out oil at sustained high rpm's (puking it out the cap). Enough to have to refill every couple hundred miles. Would that be the pump? Or, more precisely, the valve? My guess is that I wouldn't be able to order a valve assembly, and I don't feel like crawling under every vehicle with 8" clearance at the local small yard to try to find one...

I'm at a loss on this one...

Any and all ideas will be appreciated!

 

mine used to do this.. at any rpm..

I just jacked up the front and took the cap off and worked the steering slowly back and fourth for awhile to get air out of the system.

have you checked your return line for blockage?

 

budgreen: I've done the bleeding thing, and it hasn't improved. It doesn't do it except for at higher rpm's, so that's different too. When turning lock to lock with the engine off, I was getting like one bubble when turning to the right, and 5-6 bubbles most everytime when turning to the left.

I haven't checked the return line for blockage - think I'll do that tonight. If that's not blocked, I might pull the valve out of the canister and see if that screen's plugged. If I cannot find anything, not sure what my next step will be...

Thanks for the input, and keep it coming guys. Thanks!

 

I'm not really wanting to be the one to say this after the other info but If you are sucking air into the return side then it will foam, but may not leak out of where ever you are sucking air. Think of it like the fuel supply, when we get an air leak at the heater gasket, the truck runs like **** and smokes grey, but not always will leak diesel out on the ground. Good Luck with finding it.

 

The more I think about this, I don't think having a leak on the return side would even result in what I'm seeing. I don't even think it would pick up any air, in a normal situation. I think one could cut that line, and, sure, other things would happen, but I don't think air would be interjected into the fluid enough to damage anything/show bad symptoms. Keep in mind that I'm talking about running the pump for a second, and not long term. I realize that, to operate properly, one couldn't cut the return line - I'm simply using that as an illustration. It isn't a completely closed system. And a pinhole that's not even leaking, on the return line, wouldn't cause a problem except for maybe some very mild foaming. Not what I'm seeing.

I took that valve out and the screen looked good. Had very little debris on it. Not the problem.

I guess I'll take all of the return line off and make sure things are flowing. It would seem to me that, even if that return was blocked pretty significantly, it wouldn't pressure anything except for the steering box - which would result in it blowing seals in the steering box. The pressure might back up to the discharge side of the pump, but wouldn't back through the pump and surely not all the way back into the reservoir. Intuitively, that would seem to make sense, although I might be way off base.

Still hoping to hear more ideas from you guys... Thanks.

 

mine foamed from the cap like that too. ended up being a bad pump

 

tltruck: did it overflow from the cap enough to get things seriously wet? Did it only overflow once the truck was shut off? Did it overflow primarily during higher rpm sustained running? I'm curious to know these things - that way, I can go from there...

Thanks

 

mine leaked a lot like that i found the bottom bolt that hooks to the motor bracket was loose its hard to see