Engine Power steering pump advice

[ReefBlueGT]

Hi all, lately the power steering on my 93 5.0 has felt like it’s cutting out occasionally, resulting in a pull. Happens maybe once every couple days or so, when braking and coming to a stop, or when accelerating from a stop or near stop. It’s a daily driver, so it gets taken out twice a day at least 4 days a week, mainly surface streets. No strange noises or excessive whine coming from the pump that I’ve noticed.

Tonight I took the cap off the pump to check the fluid, and it looked pretty low. Still some in the reservoir, but not enough to hit the dipstick on the cap. Also smelled metallic and slightly burnt, looked like weak chocolate milk. I don’t have fluid leaking from anywhere in the steering system unless it only comes out while I’m driving.

Should I top off the fluid? Or drain out what I can and refill with fresh new fluid? Or is my pump probably toast?

 

[manicmechanic007]

If it is not whining your pump is not toast
However loss of assist (when full of fluid) means the pump might be shot
Chocolate milk? It should be red trans fluid darkened by the aluminum rack
That means I would try to replace the fluid and re evaluate the concern
Used to pull the return line off and plug the intake port
Add additional hose to the return line with a splice and run it into a bucket
Then add a ton of fluid and start the car
Keep adding fluid until you are satisfied it is coming out clean red
I turn the wheel back and forth some during this process
Good luck use mercon if you can find it

 

[limp]

I would be looking at a bad belt that is slipping... Has it been wet or raining when doing this?? Water splashing on it making it worse...
Simple things first....... Check/replace belt, flush fluid.......
Damn, I am thinking old school again.... Not a separate V belt is it....LOL......

 

[ReefBlueGT]

Update on this…while checking on a couple other things this morning, decided to take a closer look at the pump while idling and also turning the wheels while parked. Didn’t see the fluid circulating in the reservoir while the car was idling, it just sat there. Cranked the wheels back and forth a few times, and the PS whine seemed a little loud and also slightly metallic, almost like a light grinding sound. Could definitely smell a little burning in the area near the pump afterwards, but no visible smoke.

Serpentine belt was replaced within the past couple years. No rain or splashing into the engine compartment here in SoCal. Has definitely been dry when I’m experiencing the occasional PS loss. I found a couple of cracked vacuum fittings on the air system this morning so I replaced them. I know a vacuum leak could cause temporary PS loss under load, like when braking or accelerating. So maybe that explains that part of the equation.

But I’m thinking the pump may be barely working since I still have PS function, but is probably on its last legs with the grinding/burning and no visible fluid circulation? Maybe the fluid is really only getting moved around from the pressure of the wheels turning while driving? Or am I way off?

 

[limp]

I would still change the fluid and give that a try... Take off the belt and turn the ps pulley by hand..... See how it feels?

 

[ReefBlueGT]

Hand turning is a good idea. Guess I will give a fluid change a shot first.

 

[7991LXnSHO]

If it is not whining your pump is not toast
However loss of assist (when full of fluid) means the pump might be shot
Chocolate milk? It should be red trans fluid darkened by the aluminum rack
That means I would try to replace the fluid and re evaluate the concern
Used to pull the return line off and plug the intake port
Add additional hose to the return line with a splice and run it into a bucket
Then add a ton of fluid and start the car
Keep adding fluid until you are satisfied it is coming out clean red
I turn the wheel back and forth some during this process
Good luck use mercon if you can find it

Why Mercon vs Type F for PS fluid? I’m used to hearing about subbing Type F for Mercon/Dexron.

(For those not up to date, Mercon/Dexron 3 (and higher numbers) is a GM and newer Ford ATF with friction modifiers, while Type F has no friction modifiers. So Type F is more of a straight, quality hydraulic fluid than the little junk bottles of PS fluid on the shelf or the special trans fluids of Dexron X. Using Type F in a GM trans will be like adding Trick Shift fluid.)

 

[ReefBlueGT]

Thanks all for your help and advice so far. I drained and flushed the pump tonight, removing the return hose from the pump only, letting it drain into a pan, so everything could circulate through the rack, cooling tubes, etc. What came out was absolutely pitch black. It was so black I could see my reflection in the pan while it was still under the car as though I was looking in a mirror. And I put over a pint of fresh fluid through the system while turning the pump by hand to flush it. It was coming out clear and fresh when I stopped. I even let it sit in there for a few minutes halfway through.

Unfortunately, after running the car for a few minutes and turning the wheel back and forth a few times, the fluid was already murky again in the reservoir. Not quite chocolate milk like before, but getting close. I can also clearly hear the pump whining as the car is idling. Not super loud but it’s there. And it gets louder when I turn the wheels.

So the pump is clearly moving the fluid but doesn’t sound too good. I know the sound can be hit or miss depending, and it’s not so bad that it’s annoying me. But getting back to the murky fluid — it shouldn’t be like that, especially right after a flush with new fluid added. Can that be caused by the pump failing, or is it more likely something in the rack or the cooling lines that needs to be replaced?

Only other note is that the auto store didn’t have any Type F in stock, so I went with Lucas Oil PS fluid to flush and fill it. Said it had conditioners and is good for all PS systems. Can using PS fluid instead of Type F cause this problem or is that not a major concern? I’m pretty sure it had PS fluid in it prior to my flush because it was last done at an oil change place a couple years back.

 

[General karthief]

When I replaced my rack and pinion this is how I flushed the fluid, return line in a bucket, vacuum cap on the return line nipple on the pump, with the pump full I started the car and kept the pump full, after a quart through the pump I had someone turn the wheel lock to lock while running another quart + through it, I did use ps fluid but you can use ATF, I think it doesn't have to be F type but
I still have the original pump and it's pretty quiet.

 

[ReefBlueGT]

Thanks @General karthief. I used a vacuum cap on the reservoir tonight too. And the hose just went into a drain pan. But probably a good idea to move more fluid through there and while the car is running. Plus the wheels turning to make sure it gets worked through the rack and back out. Once I get back to the store again and pick up some ATF fluid I’ll have to give it another shot.

 

[General karthief]

Just make sure you keep the pump full, it pumps out pretty good.

 

[7991LXnSHO]

Thanks all for your help and advice so far. I drained and flushed the pump tonight, removing the return hose from the pump only, letting it drain into a pan, so everything could circulate through the rack, cooling tubes, etc. What came out was absolutely pitch black. It was so black I could see my reflection in the pan while it was still under the car as though I was looking in a mirror. And I put over a pint of fresh fluid through the system while turning the pump by hand to flush it. It was coming out clear and fresh when I stopped. I even let it sit in there for a few minutes halfway through.

Unfortunately, after running the car for a few minutes and turning the wheel back and forth a few times, the fluid was already murky again in the reservoir. Not quite chocolate milk like before, but getting close. I can also clearly hear the pump whining as the car is idling. Not super loud but it’s there. And it gets louder when I turn the wheels.

So the pump is clearly moving the fluid but doesn’t sound too good. I know the sound can be hit or miss depending, and it’s not so bad that it’s annoying me. But getting back to the murky fluid — it shouldn’t be like that, especially right after a flush with new fluid added. Can that be caused by the pump failing, or is it more likely something in the rack or the cooling lines that needs to be replaced?

Only other note is that the auto store didn’t have any Type F in stock, so I went with Lucas Oil PS fluid to flush and fill it. Said it had conditioners and is good for all PS systems. Can using PS fluid instead of Type F cause this problem or is that not a major concern? I’m pretty sure it had PS fluid in it prior to my flush because it was last done at an oil change place a couple years back.

I will confirm If you did not turn the rack side to side several times while doing the flush that not all the fluid was changed. Run the wheel side to side with the pump spinning with the current fluid, then do the flush again with the extra help to turn the wheel during the flush.

The conditioners in Lucas Power Steering Fluid are seal softener. I trust Lucas products to be premium priced copies of good products. It should be a fully functional hydraulic fluid. Other PS fluid on the shelf that’s not marked as meeting a brand or industry standard will have questionable viscosity and other issues.

@manicmechanic007 ‘s Mercon/Dexron (insert number) suggestion is likely an acceptable, cheaper and high quality substitute for Type F in this system. I have not heard if the friction modifiers for the auto trans clutch bands/plates help with PS pump noise.

PS fluid needs to be able to take high temp at least as well as an auto transmission. It has a small volume of fluid that is worked the whole time the engine is on, and few systems have a cooling loop or finned cooler, or a filter.

 

[ReefBlueGT]

Excellent info @7991LXnSHO. Thanks!

 

[7991LXnSHO]

Excellent info @7991LXnSHO. Thanks!

I hope it helps.

 

[90sickfox]

I usually use mercon iii ( if I can fimd it ) or mercon v in customers or my normal foxes. My pumps have always been quite. My current set up takes European Pentosin due to using the Volvo electric PS pump.

 

[limp]

My current set up takes European Pentosin due to using the Volvo electric PS pump.

I have one of those too..... That stuff is expensive....

 

[manicmechanic007]

Which Vulva did you get the pump off Sic Fox?

 

[ReefBlueGT]

@General karthief you weren’t kidding about the pump spitting that fluid out. Tried it with the engine running first, but it got slurped down and spit out faster than I could refill it. But was able to turn the wheel a few times. Then switched to cranking the engine only and also turning the wheel. Much easier to manage. After putting over two quarts through and seeing only the ATF fluid come out, I was satisfied that I got all the old stuff out. Cleaned everything up and reconnected, let it idle for a bit and turned the wheel some more to try and bleed any leftover air out. Still a bit of a whine when turning the wheel, but not as bad as before, and no audible whine at idle. So I’m happy — except for the huge mess on the driveway from some splashes that missed the drain pan.

@7991LXnSHO the auto store didn’t have any Type F but I went with Valvoline Maxlife synthetic ATF as a substitute. So far so good. Fluid has kept its color and doesn’t look burnt or murky yet so that’s an improvement.

 

[7991LXnSHO]

If that is Dextron VI, it is a good upgrade. I need to post a tech note about what I confirmed with an industry insider. But you did good.

 

[General karthief]

I used a 5gal bucket with a big nut zip tied to the end of the hose, no muss, no fuss.
Guess I could have mentioned that..