HMMWV Power Steering Whine

[daedna]

Hello,

I'm relatively new to this site, so go easy on me...lol

I bought a M998 a few months ago, it had some mechanical issues one of which was that the power steering pump had been partially removed...basically no belts and loose bolts. So I figured somebody was in the middle of changing out a pump and didn't finish, so I bought a pump for a Chevy pickup (typical canned ham style pump) and installed it. Bled the system and the truck came back to life, ie. had power steering, power brakes, generator worked, etc..and I don't have any leaks except from the reservoir cap. But there is an whine that is not there at idle, but starts just off idle and increases with rpm. I don't have the typical moaning sounds if turning when you are low on fluid...just this constant whine...sometimes quite loud. So far over the past month or two I have tried:

replaced all low pressure lines and installed with double clamps at each connection
Pressure tested PS fluid cooler including hoses leading to it @ 15psi...no leaks
Tried bleeding with procedure found on this site, wheels in the air, engine off, 40 times left-right, etc....
Tried same procedure engine running

Nothing has gotten rid of the whine, most of the time it gets worse after messing with it.

Trying to bleed with the engine off leads to the fluid level rising until it spills out (a lot of fluid, not just a few drops)

If you observe the fluid when the truck is running, it is pink and frothy. After engine is shut off, bubbles surface while the fluid settles.

Does anybody have any suggestions? I'm assuming air is getting in somewhere but I don't know where to look or how to evaluate the hydroboost or fan clutch setup...other than to look for leaks (which they don't leak)

Thanks in advance....this is really kicking my butt

 

[daedna]

m998 with power steering whine

Hello,

I tried to post this earlier but it looks like it didn't work so here goes again with a little less detail....

I have a terrible whine that sounds like it coming from the power steering pump....

I have tried bleeding the system multiple times using several methods, I replaced all hydraulic return lines, leak tested the cooler and some of the lines, and replaced the pump. There are no leaks anywhere and brakes and steering more or less work normal.

If I try to bleed the system with the engine off, the fluid rises (while turning the wheels back and forth with front end off the grounds) until it spills all over the floor

If I observe the fluid with engine running, it is pink and frothy. Turn the engine off and it bubbles until the "froth" settles back into red fluid.

Is this an issue with the hydroboost? Can it be repaired or do have to replace it?

Thanks in advance!

Dave

 

[Bravojmc]

Hello,

I tried to post this earlier but it looks like it didn't work so here goes again with a little less detail....

I have a terrible whine that sounds like it coming from the power steering pump....

I have tried bleeding the system multiple times using several methods, I replaced all hydraulic return lines, leak tested the cooler and some of the lines, and replaced the pump. There are no leaks anywhere and brakes and steering more or less work normal.

If I try to bleed the system with the engine off, the fluid rises (while turning the wheels back and forth with front end off the grounds) until it spills all over the floor

If I observe the fluid with engine running, it is pink and frothy. Turn the engine off and it bubbles until the "froth" settles back into red fluid.

Is this an issue with the hydroboost? Can it be repaired or do have to replace it?

Thanks in advance!

Dave

sounds to me like you still have air in the system if it's frothy...

 

[Rmtaunton]

PLEASE Help with HMMWV Power STeering Whine

You def have air somewhere


If it's a winch truck make sure to bleed it as well ,, it should naturally get the air out with minimum turning of the wheels.

Sent from my iPhone using Tapatalk

 

[doghead]

Merged your threads, and changed title to conform to our site rules/etiquette.

 

[3jacks]

Hello,

I tried to post this earlier but it looks like it didn't work so here goes again with a little less detail....

I have a terrible whine that sounds like it coming from the power steering pump....

I have tried bleeding the system multiple times using several methods, I replaced all hydraulic return lines, leak tested the cooler and some of the lines, and replaced the pump. There are no leaks anywhere and brakes and steering more or less work normal.

If I try to bleed the system with the engine off, the fluid rises (while turning the wheels back and forth with front end off the grounds) until it spills all over the floor

If I observe the fluid with engine running, it is pink and frothy. Turn the engine off and it bubbles until the "froth" settles back into red fluid.

Is this an issue with the hydroboost? Can it be repaired or do have to replace it?

Thanks in advance!

Dave

In addition to above, check your return lines from hydroboost and Cadillac valve...they may be reversed. I did this and it was an awful noise.

https://www.steelsoldiers.com/showt...h-outlet-on-PS-Pump-is-the-line-to-hydroboost

 

[tage]

Air, or fried pump.
Is it hard steering?

 

[Sintorion]

I had an issue with my power steering a few weeks ago. Mine lost all fluid and I drove it about 5 miles home. I tried to bleed it on the ground with the engine running. I end up with a massive over flow of angry fluid probably similar to what you experienced. The pump whined like crazy. I thought I had toasted the pump. As a last ditch effort I followed the bleeding procedure exactly. In the air, engine off, left right, left right, keeping a constant eye on the fluid level. Started it and it whined a little then went away. There are more steps if you have noise, but mine was quiet.

There is a possibility that it could be the pump. The stock gm pumps are supposedly different than the AMG pump. I couldn't find any definitive proof, but there is enough info out there that it scared me away from a GM pump. If you decide you want to go with an OEM pump, let me know because I have a brand new OEM AMG pump that I will make you a good deal on.

 

[Action]

Is the non original pump you installed supposed to spin the other way to operate properly?

 

[daedna]

in response:

It is a winch truck, but its an electric winch

I'll look into merging the threads and renaming....but I don't know exactly how to do it.

I will try switching HB return with Cadillac return tomorrow....but this pump is for a different vehicle and the return nipples are not in the same spot on the reservoir as the original. I did not know why they had so many variations of the "canned ham" GM pump....I figured it was just to accommodate different vehicle configurations but that there were no "real" differences. Does it matter where in the reservoir the return lines attach (ie. below fluid level, above fluid level, left, right, etc...)??

Steering, braking, and fan clutch operation are normal as far as I can tell.

In a desperate measure I ordered a new hydroboost (based on diesel forum posts), if that doesn't work I would greatly appreciate if I could get that pump from you. I will follow up in 2-3 days.

In all honesty, I have no idea what direction the pump should spin...I had just got the truck was anxious to get it going. I'll have to go back and figure out what exactly that pump is used on and go from there.

Any other suggestions? I will have time tomorrow to work on this....

Thanks again for the help!

 

[daedna]

In addition to above, check your return lines from hydroboost and Cadillac valve...they may be reversed. I did this and it was an awful noise.

https://www.steelsoldiers.com/showt...h-outlet-on-PS-Pump-is-the-line-to-hydroboost

You were right!...this eliminated almost all of the noise.

Thanks a bunch....I didn't want to drive the truck anymore the noise had gotten so bad!

I never realized that it mattered which return hose goes to which nipple...but apparently it does.

 

[jeffy777]

You were right!...this eliminated almost all of the noise.

Thanks a bunch....I didn't want to drive the truck anymore the noise had gotten so bad!

I never realized that it mattered which return hose goes to which nipple...but apparently it does.

That is what I like about SS and guys like 3Jacks. We are lucky they share their vast knowledge! GREAT JOB 3Jacks!

 

[FlameRed]

In addition to above, check your return lines from hydroboost and Cadillac valve...they may be reversed. I did this and it was an awful noise.

https://www.steelsoldiers.com/showt...h-outlet-on-PS-Pump-is-the-line-to-hydroboost

All hail the Great and Mighty @3jacks !

I replaced my PS pump when I replaced my generator as I noticed a few drops of fluid and figured, while I am in there....

But I too got the dreaded squeal of a million fingernails across the cault board and I was pulling the little hair I have out trying to get rid of it doing the turning stop to stop a gazillion times. I had VERY carefully labeled the hoses and I an positively certain I was thinking the pump was defective.

I installed the hoses as they were originally. But I guess it wanted them reversed! As soon as reversed the hoses no more noise!

You deserve the member of the year award!

Thanks you!

EDIT: Found a great diagram for the M998 of how these hoses should hook up:

 

[TOBASH]

Flame deserves member of the day... He used the Search!



Seriously, awesome work!