2 Problems; Brake whining & rear tire thumping **UPDATED**

[erasedhammer]

Here we go again.

So for the tire problem I had Les Schwab 'check their work' and would you look at that! They never balanced them after replacing the old tires... but that didn't fix the problem. Run flats are secure and tire is balanced.
Symptoms:
Thumping sound that increasing frequency with speed.
Sound comes from left rear tire area.
Thumping only occurs under acceleration or light braking.
In reverse there is a clicking sound like the wheel of fortune when coasting backwards.
Thumping frequency is also effected by throttle position (full throttle it has a high frequency than 1/4 throttle)

There was brown grease stains on part of the tire that looked like it drained from inside the rim. I'm thinking the geared hub is the problem, but would like confirmation before a drop money on a new one.

SECOND PROBLEM:

This may be a low fluid level (I'll be checking tomorrow) but as soon as I turn the vehicle on there's a loud hissing/whining sound coming from the master cylinder/hydrobooster area.
Sound gets louder when I turn or brake.
There is a crackling sound when the brake pedal is fully depressed.
I notice no decreased braking pressure of the pedal though. Same force required just with added annoying sounds.
Whining/crackling sound is almost as loud as the engine now.

I think the pump is going bad since loss of fluid would mean loss of brake pressure, right? And same as before I'd like to confirm before I buy a new hydrobooster.

 

[NDT]

1. Geared hub
2. PS Pump.

 

[erasedhammer]

1. Geared hub
2. PS Pump.

Can you provide a diagram of the power steering system or a link to a section of a manual?

 

[kdaniels]

Check your half shafts....make sure they are in good condition and not loose.

Semper fi !

keith

 

[erasedhammer]

1. Geared hub
2. PS Pump.

So replace both the geared hub and PS pump?

What can happen to a geared hub that would make a thumping sound? Can it be repaired rather than replaced?

Also is the PS pump the hydro-booster or is a separate pump? I heard they both pulled from the same reservoir for fluid. If not, where is the PS pump?

 

[Action]

The PS pump is closer to the fan. The pump IS the fluid reservoir. It has a pulley on it and is almost teardrop shaped. It has a screw on lid.

 

[Retiredwarhorses]

So replace both the geared hub and PS pump?

What can happen to a geared hub that would make a thumping sound? Can it be repaired rather than replaced?

Also is the PS pump the hydro-booster or is a separate pump? I heard they both pulled from the same reservoir for fluid. If not, where is the PS pump?

I do suggest you read the TM's...there are a lot of excellent diagrams of the various systems in the truck as well as explaining how the systems function.

You don't need to replace your entire geared hub, everything inside of them is rebuildable.
my suggestion is to find a reputable HMMWV mechanic and work with him.