Weak power steering with a squealing pump belt, but brakes and winch seem fine

[kestrelnh]

Hi all. I was out today with the HMMWV off road, and when the truck is stopped, the power steering is very weak. When stopped the belt (which is pretty tight) squeals like crazy when trying to turn. The brakes seem just fine, and the hydraulic winch seems fine. Once moving, the steering seems fine, but I do hear the occasional squeal of belt noise when turning. I think the reason I may have noticed this more today is I aired the tires down.

The steering has always been a bit weak in this rig, but it seems to have gotten worse last year when I put the MM hydraulic winch on. It took me forever to get air out the system, and the presence of the winch seems to be putting some additional strain on everything.

I'm going through the air removal procedure again now, but can anyone with experience point to a likely problem area, or the first part to throw at it?

 

[DainGerous]

Suppose a bunch of questions:
Fluid leaks?
Dirt like grease at P/S pump?
Burnt oil smell?
Joints/Steering linkages worn?
Newly flushed power steering fluid?
New power steering hoses? New o rings?
Power steering pump original?
Age of belts?
Power steering gear original?
Hydoboost?

Replaced my whole Power Steering system.. Pump looked original 1987. Power Steering oil cooler newer (2006) but filled with black sludge. Power steering gear/master cylinder 1987 original. Even though no problems before.. she drives like a dream now.

Could be air in your system.. leak from hoses, pump, etc. Or general metal fatigue, material deterioration, sludge, etc. I'm sure someone here can chime in with the main culprit.. but you may want to swap out a few more things while you're at it. ePay may have some new cheap parts.. joints, hoses, etc ~$50.

 

[kestrelnh]

Thanks!

No leaks, no burnt smells, reservoir is full.
The steering moves without too much effort with the truck off and wheels off the ground. I had replaced a lot of worn components in the steering last year.
The age of all components but the new hoses I put on to mount the winch are unknown, but the truck is a '92, so may be that old.

Flushing the system and replacing the belts are good ideas, and can't hurt. Replacing the low pressure power steering lines would be pretty easy, and I can clean up stuff when I do that.

It looks like the hydroboost has its own return, so maybe that's why it's working correctly? However, on the other loop, only the power steering is having trouble, the winch and cooling fan seem to work OK.

My recollection is the problem got worse when I put the winch on, so maybe there is something up inside the winch, or perhaps I fouled up a connection. There is a tube to bypass the winch solenoid block, but I can't find one online. Does anyone know what connectors those are? Perhaps I could braze one up.

 

[tage]

Sounds like your pump is going out

 

[kestrelnh]

So, after just loose belts, the pump was my first though too. What I'm confused about (never had a pump go bad in my relatively short lifetime) is, why would the belts squeal with a bad pump? Would' the squealing belts indicate the pump is working really hard, or can it work hard and be weak at the same time?

 

[kestrelnh]

Last night I changed the fluid by running the truck and draining from the fan hookup on the activated Cadillac valve. At least temporarily, the problem seems to be fixed. The weird thing is that without noticeable change in flow from the low pressure hose I was draining from, fluid seemed to empty VERY quickly at first from the reservoir, and then much more slowly, so I wonder if there was a huge air pocket somewhere in the system, or the fluid was wrong, or who knows.

I'll change the low pressure hoses for good measure.

Thank you for all the help!