Power steering and AC problems

I have some power steering issues going on in my '99 Tacoma. After driving for a while I get a nasty whine when I turn and I've got a small leak in the rack. The leak is just enough to make the boot a little wet, but not enough to drip or even show up on the power steering dip stick.

Also, my AC is barely blowing cool. And, when I use the AC the power steering whine gets much worse. If I don't use AC I don't notice the steering noise very much at all.

Any chance the two are related? I know the belts all wind around together down there.

Any ideas for either/both issues?

Are rebuilt power steering racks the way to go?

 

Two seperation problems...IMO.

1. PS: are you sure it is a small leak? If you jack the front up and have someone turn the wheel to full lock on the wet boot side, does it spray fluid out? If you are losing fluid, then that is the whine from the ps pump. Also, pull the vacuum hoses from the PS high pressure line. If there is any fluid in the hose, replace that vacuum air control valve as it is pulling ps fluid into the intake and burning it (been there).

2. When your AC is on, there is increased tension on the belt and accessories. What size motor? May be a loose belt depending on what motor you have. May be a lot more expensive. I would have a shop test the AC system after you check belt tension.

 

Its a 4 cylinder, 3RZFE.

I'll jack it up and see if any fluid comes out when turned to lock out. I've never seen any on the ground or have had the dip stick come up low, but I don't typically turn to lock out either.

I know the belts are old and need replacing. Hopefully thats what's going on. I don't like the idea of the expensive AC repair.

 

I have the same leak out of the top of my steering rack, just too cheap to replace it rn

 

I spent some time with the truck on stands. No power steering fluid squirting or excessively leaking when the wheels are turned. Seems like the leak is inside the boot on the driver side.

All belts are tight, but need replacing.

I did notice that when I turned on the AC, the power steering fluid (ATF) would get foamy like air was in the line. I flushed the fluid (remove return hose from reservoir, turn wheels lock to lock till new fluid came out; keeping reservoir full) but it didn't seem to help. It's fine if I don't turn on the AC, but when I do its not long till the fluid foams again.

I don't know why this would happen, but it seems to be more than coincidence.

Could the AC be causing the PS pump to pump too fast and pulling air in the system? With the PS cap off, truck on, I noticed the fluid makes a whirlpool in the reservoir. I could see that getting air in the system. Is this how it's supposed to work? I've never looked in the open PS reservoir with the truck running before so I don't know.

Any ideas?

 

The PS fluid will spin when the pump is running. You will have to bleed the PS system a bunch of times to get all the air out. If you know there is no air, but you are seeing foaming/frothy fluid with the AC on, then you are definitely getting air in the PS system. The AC/PS are separate systems and do not share fluid, so it shouldn't be an AC causing PS issues, other than increased load on the motor. Is this a manual transmission? Did you check the air control valve on the high pressure power steering line to see if any fluid is in the two vacuum hoses?

 

Turning on the A/C does increase the idle-speed. That would affect the PS pump.
You could have a plugged-up PS filter screen (in the bottom of the PS reservoir).

 

It is a manual transmission.

I checked the hoses on the valve, both were dry with no evidence of fluid on either end. (should be dry right?)

My reservoir doesn't have a screen. I removed it (the reservoir) to try to clean out the screen after I saw a few posts about it causing issues. All the pain to get it off (one bolt is a pain) and no screen. I'm not sure why, because I'm the original owner of the truck and I never removed it. Way back, when my truck was under warranty, I had power steering issues and the dealer fixed it. Maybe they swapped out the reservoir with a screen-less version? Or maybe 99s didn't have it. Not sure.

I wouldn't have mentioned the AC, but it's fine till I turn it on. After flushing and bleeding the PS I drove around for 15 or 20 min, no issues. Flipped on AC and within 20 seconds stiff steering and PS whine. Weird.

 

They should be dry.

If it only happens when AC is on, i'm betting AC is the problem. AC clutch maybe? If it is AC, it is probably time to see a mechanic. Even if you get a used compressor, you won't be able to recharge the system... May even be worth the $100 bucks to let the dealer diagnose.

 

The AC system is a wholly separate system from the PS. The increased load may cause you to notice the rack leak (air getting into system from the rack leak), but it is honestly just a SWAG.

 

Did a little more looking into this and with the AC on, truck on the ground, wheels being turned, the fluid in the reservoir draines so quickly you can see the bottom of the reservoir, down into the neck leading to the pump. This has to be how air is getting in.

I mentioned it to some old timers and they recommended using a thicker fluid and/or adding stainless steel pot scrubber to the reservoir. I looked online for the scrubber recommendation and saw some post about using them with some luck in older cars. I decided to go with another suggestion, mentioned in one of the scrubber posts, and put a piece of a hose clamp in the reservoir to disrupt the flow.

It seems to have done the trick, no more foaming fluid. I drove around with the AC on for a few miles and no issues. Before, it was instant grinding. Hopefully it stays that way.

 

Thanks for keeping us updated on what did the trick for you. It makes me wonder if you had that screen at the bottom the reservoir, would that be enough to keep it from sucking in air?

 

Maybe. The screen should disrupt the flow as good as, or better.