Help Identifying Noises on HMMWV

[honor first]

Howdy All,

Looking for some insight on these two different noises on my 2007 M1097R1 with 50k miles.

As you can hear, there a pretty distinct power steering noise when turning the wheel and stationary.

Additionally, there is a pretty loud noise when depressing the brake pedal while parked, in neutral, and parking brake engaged.

For all I know these are normal, but I'm guessing not. This is my first HMMWV. Any help is appreciated. I have pretty good basic mechanic skills and knowledge of concepts, but I've never messed with a PS pump system before.

Thanks!

 

[TOBASH]

That is your steering pump. You probably have air in the system. That pump also provides braking power explaining the braking noise.

Try bleeding the system of air. First fill fluids to line, then lift front 15 degrees, and with engine on turn lock to lock 20 times. That should fix it IF the pump is OK.

Otherwise you have an air leak or a bad pump or you didn’t follow the instructions above.

 

[frauhansen]

My hydralic i leeking and i have the same sounds when it running low on fluid.
Sounds the same as i received my rig and drove it 600mi home without any steering assistence. But brakes where perfect. Looked in the reservoir and it was perfectly filled. But... it was'nt! The was Air in the steering part. Everytime i use the steering it sucks all the fluid out of the tank.
So i do this:
The best way for bleeding the system, that i know, is to lift the trucks front axle so the tires are in the air.
On guy will keep the fluid level in the steering fluid tank permanent full. The other steers 40x full left an right. All this at running engine.

 

[honor first]

Wanted to update you all and let you know following the TM for bleeding the system to a T resolved my noise. Thanks all.

I can see why so many HMMWVs have these noises, The turning and hold at full turn 40 times takes time, as well as the steps for allowing to cool and refilling. Those E-3s are turning the wheel three times and checking that box on motor pool Monday

See below:

 

[Autonomy_Lost]

Fyi, the power steering pump on my 2007 m1151 is a little on the loud side. Thats even after getting all the air out and making sure its not foaming. Not sure if thats normal but I'm thinking about swapping the fluid with some red line ATF which I've heard might quiet it down.

 

[Mogman]

Fyi, the power steering pump on my 2007 m1151 is a little on the loud side. Thats even after getting all the air out and making sure its not foaming. Not sure if thats normal but I'm thinking about swapping the fluid with some red line ATF which I've heard might quiet it down.

All the trucks with the remote reservoir have gear type pumps, all gear type pumps make noise, that is why you don't see them on civy vehicles, think log splitter, skid loader or trackhoe. all of them have pump noise, changing the fluid will not change that.

"The hydraulic noise is mainly generated from pressure peaks that arise from entrapment of the fluid between the crest and root of the gear teeth. During the delivery phase, the trapped fluid reaches very high pressure spikes, which cause the noise, vibration, pressure ripples, and mechanical stress."

 

[Autonomy_Lost]

All the trucks with the remote reservoir have gear type pumps, all gear type pumps make noise, that is why you don't see them on civy vehicles, think log splitter, skid loader or trackhoe. all of them have pump noise, changing the fluid will not change that.

The hydraulic noise is mainly generated from pressure peaks that arise from entrapment of the fluid between the crest and root of the gear teeth. During the delivery phase, the trapped fluid reaches very high pressure spikes, which cause the noise, vibration, pressure ripples, and mechanical stress.

Thanks. When I originally got the truck (auction truck) it was low. I fixed a leak, topped off and bled the system using some generic dexron III. Do you think there is any benefit to swapping the fluid to something like Red Line D4 (which complies with Dexron III)? I figure using a higher quality product cant hurt, but I also dont want to throw my money away.

 

[Mullaney]

Thanks. When I originally got the truck (auction truck) it was low. I fixed a leak, topped off and bled the system using some generic dexron III. Do you think there is any benefit to swapping the fluid to something like Red Line D4 (which complies with Dexron III)? I figure using a higher quality product cant hurt, but I also dont want to throw my money away.

.
I would stick with Dextron. It works.