Found something out yesterday about Ford P/S pumps (and their whine)

[Captain Ledd]

I had always figured Ford P/S pumps just whined. That was the way they were. The end.

I was riding along with my friend the other day in his Mercury Sable, we just changed the trans fluid and he was commenting on the test drive that he needed to bleed the P/S pump because it was particularly loud. I informed him it may be a wasted effort because all Ford pumps seem to have that dull whine.

Then he came right back and told me something that he had found out from one of his old mechanics teachers. That you have to bleed the pumps under vacuum, all ford pumps, otherwise it it literally impossible (by design) to get all the air out of them.

His teacher had another Ford (can't remember what) had it into 3 shops and a dealership to fix the horribly loud whine. could not figure it out, several new pumps, etc (warranty). So he sent my friend into the library area of the auto shop to see if he could find some way of fixing the whine that they haven't tried. And in some dusty old book it mentioned bleeding it under vacuum. He found some equally dusty clear plastic pieces that looked like they were made for sealing a hole the size of a P/S pump that had a fitting and could suck air out. Tried it on the car and sure enough, air came bubbling out and it eventually quieted down.

I guess you need to do this while it's running, and make sure you keep it under constant vacuum while turning the steering wheel lock to lock, make sure the fluid level stays where it should be.

He said anything will work so long as it can keep pulling a vacuum.

Hopefully this can be a cheap fix (or at least attempt) before people go replacing pumps or switching to the Saginaw style pump (which while easy still requires a new pump). Worth a shot I think.

 

[MAKG]

I don't see how vacuum can matter. The fluid is under pressure. You can generate many times as much pressure as you can vacuum, very easily.

I managed to get mine really quiet, but the trick was to remove the load by raising the front end (or popping the steering linkage off the Pitman arm), and running the steering wheel very slowly stop-to-stop with the engine off.

 

[Captain Ledd]

I'm not sure how it works. But it did fix that car. The rest is what the book said (and I think Ford used very similar or even the same pumps on all their cars).

My fluid probably needs changed (as it is black), and power steering fluid is not that expensive. It whines as it is because I let it get low a while back and noticed it was whinier than usual.

I'll try and build a jig that will work for cheap and see if I can change it out next week sometime.

 

[racinranger]

I'll tell ya how it works, MOST new cp3 style pump cars with remote resi's need to be bled under vacuum along with some sho taurus's and other vehicles that have issues. The shop manual for most fords atleast the EVTM says to bleed under vaccum and turn the wheel slowly lock to lock 20 times with the vehicle off. then resume the operation under vacuum with it running. I do it daily at work in the dealership. air is trapped in the upper pump housing cavitating before it gets pulled through the vains/diaphrams of the pump and made into pressure. so for once not to call you out MAKG is not correct in assuming it would be under pressure. because its not YET at the pressure point in the pump its trapped on the ambient side. just alittle FYI.,

 

[bobbywalter]

and also, if you have big tires and no big cooler forget it. you will have to bleed it constantly every time the tires get wedged and you manhandle it, it starts whinin again. rotten lil fliud smokin bastards...


i gave up 10 years ago. only time i notice it now is if i am watching a video of the truck moving.

 

[Sasquatch_Ryda]

My fluid probably needs changed (as it is black), and power steering fluid is not that expensive. It whines as it is because I let it get low a while back and noticed it was whinier than usual.

FYI, your truck takes Mercon ATF, not powersteering fluid.

 

[exbass94]

FYI, your truck takes Mercon ATF, not powersteering fluid.

Except if it's an older one (1983-1994?) it uses Type F ATF.

 

[Captain Ledd]

FYI, your truck takes Mercon ATF, not powersteering fluid.

oh......

well it's got some power steering fluid in it now

oh well lol.

*edit - actually I put straight power steering fluid into my '84 and it actually drove nicer than the stock '97. Never aligned except for a basic toe adjustment and a fresh 6" lift with 33's.

And to hijack my own thread, any one care to explain the difference or the damage it can cause?

 

[Yellowsplash]

Up to 95 uses ATF Type F. 96+ uses Mercon ATF.

Power steering fluid will make that pump whine much more than they already do...

 

[oughtsix]

I had an 83 F150 that had an interesting cocktail of fluid in the ps pump. PS Fluid, ATF, 20W-50, Lucas. Whatever I had on hand really. Could never hear it over the engine, but it would bark at either stop. Probably not good for it at all, but it worked for a long time like that.