HMMWV Noisy Steering pump - New install, Any help?

[Valleyordnance]

Hi Guys,

Working on our M998 Hmmwv project. Steering pump was noisy (loud humming/buzzing sound)& Hose going to fan control soleniod was vibrating badly. Replaced old steering pump with new rebuilt GM Core (this is the integral tank style pump). Primed and bled the system per TM's.

Still getting the annoying loud hum/buzz sound you can hear while driving (not like I can turn the radio up!). Checked the tank - no foam, don't think there is air in the system still? I have done the steering exercises several days in a row now and can't get rid of the **** hum!

Wondering if it maybe is supposed to be there? I'm not military and have no experience around these vehicles when they are in good shape. Wondering if it could be my fan control solenoid?

Thought about flushing the system and going with PS fluid instead of Dexron III that I used after searching around on SS. Thought I would ask for thoughts/opinions before I dump 6qt thru it though.

Thanks in advance!

Chris R

 

[Jeepsinker]

Not a bad idea to go over to power steering fluid. It is thicker and may help. You can also try draining just the reservoir and refilling it with lucas oil stabilizer. Did you bleed the air out before cranking the engine? If not, you probably scored the pump and you will never get it to stop unless you replace it again.

 

[Valleyordnance]

Swapped the pump (Again!) - Bled properly per TM. Thought it would do the trick. Same noise. After doing more detective work it appears to be the fan clutch control valve causing the noise. Does anyone know where I can find one surplus? Kascar has them but they're $265!

Thanks!

Chris

 

[Retiredwarhorses]

Swapped the pump (Again!) - Bled properly per TM. Thought it would do the trick. Same noise. After doing more detective work it appears to be the fan clutch control valve causing the noise. Does anyone know where I can find one surplus? Kascar has them but they're $265!

Thanks!

Chris

2 things.....remove the Cadillac valve and use compressed air to clean it out...reinstall it and use a piece off rubber
inner tube to isolate the valve between the body and the valve. Basically a cushion. This drops the noise by almost 80%.

 

[Valleyordnance]

2 things.....remove the Cadillac valve and use compressed air to clean it out...reinstall it and use a piece off rubber
inner tube to isolate the valve between the body and the valve. Basically a cushion. This drops the noise by almost 80%.

The Return line hose is actually pulsating at a high freq. That is what is causing the noise.

I disassembled the valve yesterday and it looks like the seat area is worn. I'm sure it's the original valve as it is an old style Kysor. It's a 84 M998. Need to find a replacement if anyone knows where they are available surplus I would appreciate the help!

Chris

 

[vitamink]

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