Power steering fluid is foaming, why?

[Darius]

I relocated my PS reservoir last year and used crappy heater hose bends to get it to line up. This involved using about 8 clamps on the suction line alone. So this winter I decided to buy a simple aftermarket reservoir and replace the line with braided line and aluminum fittings. Got the lines installed and tightened up and the reservoir fit great.

Now when I turn the engine on, the fluid instantly starts to foam like air is being entrained into it. Very fine bubbles in solution. I took the reservoir out and sealed all the fittings with RTV instead of teflon paste and let it set up for a few hours. None of the fittings leak at all, but air is still showing up in the fluid.

The only other thing I can think of is the connection between the pump and the adapter fitting is seeping air past it because it is under vacuum from the pump. If sealing this does not work, could the foaming possibly have something to do with a smaller suction line causing the hydraulic fluid to form vapor pockets?

[slow s13]

just making shure but are you using ATF fluid right?

[Romeo_rus]

Can be a hole in a line... air gets in there... another guess is boiling.. do u have a cooler?

[Darius]

I'm using cheap power steering fluid from O'Reilly's. By ATF, do you mean Automatic Transmission Fluid or is ATF a brand?? Sorry for the n00b question, but I've never had issues with cheap PS fluid before.

And the weird thing is that nothing leaks when it sits overnight. Not a drop anywhere. It can't be boiling because it begins to foam within 15 seconds of cold-starting the engine.

[slow s13]

yeah man 240's use auto trans fluid for the power steering dump that stuff out and put the right stuff in there.

[leesredgt]

I use the cheap stuff from O' Reilly's aswell and have never had a prblem.

Your sucking in air from some were.

[leesredgt]

I got to thinking,what about a small crack in the PS fluid cap?

Maybe it dosent show up untill its under pressure?

[Darius]

The PS reservoir is not a pressure-tight unit, so it doesn't matter if the cap is on or off. I will try sealing the other fitting with some RTV tomorrow to see if that helped. If it did, then great. If that doesn't help, I will swap to ATF to see if that helps.

When I started this part of the project, I never dreamed that it would be such a PITA. For how janky my previous setup was, I can't believe that it actually sealed better than this one.

[Darius]

Alright, I tightened up the -AN fittings to make sure air wasn't sneaking past them, but I doubted it would help...and it didn't. I took some pics this morning and noticed that the front of the pump, where the pulley bearing is, has some fluid residue on it. Could this be a source of an air leak and if so, can PS pumps be rebuilt?

Here's a pic:

And a pic of the foamy fluid:

[adrianfromthecastle]

just an fyi, you're supposed to use automatic transmission fluid dexron type 2, as stated in the factory service manual.

I've never seen my PS fluid that color before... but then again, I use ATF dexron 2 which is a darker reddish color

[KFL]

yeah man 240's use auto trans fluid for the power steering dump that stuff out and put the right stuff in there.

T rue, use ATF only.. power steering fluid may contain something that will break down seals down the line and mess things up. A buddy of mine used power steering fluid on his s14 it squeals like a pig. It could be the ps fluid or pump going out or a combo of booth. Told him to flush it out..Factory service manual clearly states use ATF only.

[Darius]

Alright thanks fellas! I'll go pick some up right now and change that fluid out.

[Darius]

Changed the fluid out and the Dexron II fluid seemed to help quite a bit, but it is still foaming and the PS is not functioning. I took pics of the pump and it is definitely leaking from the front seal since this was taken after I completely wiped off the hub of the PS pulley and drove it around the block.

I just replaced it with another used one, so it is possible that the guy unknowingly sent me a bad part. Pics to come.


Modified by Darius at 4:24 PM 4/18/2009

[Darius]

I removed the pump and replaced the o-rings, front main seal, and pulley (with shaft) from a known good pump. The leaking and foaming are no longer issues but the power steering still does not work. It pumps the fluid around but it isn't creating any pressure. I have a small leak at the fitting on my high pressure line, so we'll see if it helps when I stop that. I have bled the system according to the FSM, but I think there still must be some air in the rack.
Modified by Darius at 6:34 AM 5/1/2009

[0wn3r]

Dexron 2 or 3?

[Papi Chulo]

Obviously your car has Rabies.

[thoughtless]

Obviously your car has Rabies.

^^lol

[PhopsonNY]

Hey... are you sure that none of your lines are kinked?

I had a problem like that and one of my low pressure lines was kinked.

[IanS]

You need to bleed the system.

Its normal any time you work on a PS system to have air.

Let the car idle, and turn the wheel from lock to lock very slowly. Hold at each full lock for 2-3 seconds.

I have seen cars, Toyota's, Nissan's, and Ford's, that take FOREVER to bleed. When I replaced the PS cooler on my S14 it took 30 or so repetitions of back and forth, shutting the engine off every 5 or 6 to allow fluid to settle.

[Darius]

Thanks for the tips guys. The car is pretty rabid, I admit. Rabid in a good way though

Thanks for the tips Ian. I did turn the wheel from lock to lock about 3 times thinking that might do it, but apparently I needed to do it more.

Since my last post, I rejacked the car up and had my gf turn the wheel lock-to-lock with the car turned off at least 10 times or until she got annoyed. I watched the reservoir and after quite a few turns saw a few large air gulps boil up in the reservoir. In between those, there were little 1/8" bubbles. I have had the PS apart before and never had a tough time bleeding it, but we shall see if this does the trick. We are in the monsoon season in Iowa so it has been raining all week and I haven't had the car out of the garage.