M998 hmmwv brake vibration

[Bolger]

Hey gang,
I've got a 1993 m998 hmmwv.. When the engine reaches operating temp I've noticed a awful vibration noise when I hit the brakes. The information I have says this can be caused by a low steering pump reservoir. I added a little to the full mark but the problem still exists. They only thing I've done so far is that I've changed the drive belts and I had to disconnect the hydraulic line to the fan motor. Has anyone else had this problem? Could any of you point me into the right direction? Thank you

 

[Action]

was this going on before you disconnected that hose?

 

[BLK HMMWV]

Does it make the noise when stopped and hitting the brakes or when moving coming to a stop.
Why did you disconnect the fan?

 

[Bolger]

was this going on before you disconnected that hose?

Yes when it's hot

 

[Bolger]

When coming to a stop and not every Time. I had to disconnect the hose in order to replace all the drive belts.

 

[dmetalmiki]

Sound like something is loose in the suspension, If there is vibration when the brakes are applied, then logically there is a loose or broken component in the braking system, (shocks? disc pads/ mountings?..even the driveline) somewhere in that region)

 

[Bolger]

Sound like something is loose in the suspension, If there is vibration when the brakes are applied, then logically there is a loose or broken component in the braking system, (shocks? disc pads/ mountings?..even the driveline) somewhere in that region)

it doesn't happen every time any thoughts

 

[Bolger]

I guess it's more of a noise then a vibration. It stops fine and the pedal feels fine

 

[ryanruck]

Maybe consider getting the rotors machined or replaced as well as replacing the brake pads.

You might have "hot spots" on the rotors from brake pad deposits or impurities (like oil) in the pads.

It will also give you a chance to examine your calipers to make sure you don't have any cracks in the pistons, none are sticking (causing uneven braking application), and the seals and boots look okay.

Not a very expensive repair to make anyway even if it doesn't eliminate it and you've got peace of mind of new brakes. Personally, from experience, that's where I'd start.

 

[kc5mzd]

Do you have oil or transmission fluid for the power steering fluid? I might try draining about 1 quart and adding Lucas - auto trans fluid additive or synthetic oil additive depending on what you are already using in the system.

 

[Bolger]

Maybe consider getting the rotors machined or replaced as well as replacing the brake pads.

You might have "hot spots" on the rotors from brake pad deposits or impurities (like oil) in the pads.

It will also give you a chance to examine your calipers to make sure you don't have any cracks in the pistons, none are sticking (causing uneven braking application), and the seals and boots look okay.

Not a very expensive repair to make anyway even if it doesn't eliminate it and you've got peace of mind of new brakes. Personally, from experience, that's where I'd start.

Could you send me a link or manual to preform this procedure...

 

[Bolger]

Thanks for the info.. Do you have a link for a teardown replacement manual? I couldn't find anything online. I've never changed brakes on one of these and I'm still learning.

 

[ryanruck]

Could you send me a link or manual to preform this procedure...

TM 9-2320-280-20-2, Section 7-9. SERVICE BRAKE ROTOR REPLACEMENT (page 759 in my PDF)

It's pretty easy. Just make sure you've got new Grade 8 lockwashers or Nord-Lock washers (or just get 4 of these), a torque wrench, and Red Loctite to reinstall everything. Make sure everything is torqued to spec.

 

[Bolger]

TM 9-2320-280-20-2, Section 7-9. SERVICE BRAKE ROTOR REPLACEMENT (page 759 in my PDF)

It's pretty easy. Just make sure you've got new Grade 8 lockwashers or Nord-Lock washers (or just get 4 of these), a torque wrench, and Red Loctite to reinstall everything. Make sure everything is torqued to spec.

thank you!

 

[Action]

do you have the 37" tires that make a rumbling sound at a certain speed when slowing down?

 

[HMMWV V]

thank you!

Bolger did you fix the issue? I think I'm having the same problem.

 

[Mogman]

Both of my M998s make more noise from the gear hubs when the brakes are applied.
If it was something to do with the brake booster/hydraulic system it should also show up when not moving and applying the brakes.
I would just inspect all the rotors/pads and if it stops OK then just drive it until you get used to the many different things about a HMMWV.
Also inspect the half shaft boots and the half shaft/rotor bolts, this should be only one of the MANY inspections that should be done on any HMMWV when you get one and before you drive it!

 

[HMMWV V]

Bolger did you fix the issue? I think I'm having the same problem.

Bolger did you fix the issue? I think I'm having the same problem.

You out there Bolger?

 

[SmartDrug]

You out there Bolger?

February 11, 2017

 

[TOBASH]

Joined Feb 11, 2017. Last seen Feb 11, 2017.

Holy ghosting Batman. Poof! He’s gone!