M1152 leaking power steering fluid - steering gear or hydroboost?

[HookEm]

First off, thank you all who run this site for all of your help. I've been enjoying my HMMWV due to much help from you all.

I acquired this ?07 M1152 in non-running/driving condition but have had it operational for at least the past year again thanks to help from members on this site.

Most recently I noticed a sizeable power steering fluid leak around the area of the steering gear (more to come). I had known there was a small leak around the pitman arm that I assumed was the culprit, however once I put the HMMWV on the lift intending to replace this I cannot reproduce the leak. Instead I noticed the brake pedal, when pressed has a significant whine and am wondering if perhaps the hydroboost is at fault? I did confirm there's still plenty of power steering fluid in the reservoir.

I'm considering going to town with some mineral spirits as there's a fair bit of grime everywhere making accurate diagnosis difficult here but was wondering if anyone else has had similar condition and maybe had success fixing. I have been reviewing a recent Technical Bulletin with service/diagnostic procedures. Just figured I'd check here as well.

 

[mgFray]

Could be a failing hose or fitting.. I've zip tied blue shop towels to the hoses before (to make sure they didn't get in the belts and such) on compact utility tractors, gone for a drive (or let it sit)... then come back and removed the towels one by one to find the hole in the hose, or which fitting was leaking.

I don't think the pressures are as high in the HMMWV, but never a good idea to try to find a hose or fitting leak "by hand" with hydraulics.. pressure can force the fluid into your skin causing all sorts of problems.

If you don't find any issues here, definitely check that the reservoir itself isn't leaking. I've seen cases where the cap lets it leak.

 

[Mogman]

The hydro-boost is not likely causing the steering box to leak, the noise you hear is the pump having to work.
The Hydro-boost can leak, it will fall to the ground behind the drivers side front tire, the steering box usually to the inside of the driver side front tire.
I always try to caution folks not to just plant their foot on the brakes with all their effort they can muster as it can cause the hydro-boost seal to fail, a real PITA to replace.
I good car wash will clean up the grime

 

[juanprado]

When you hear the whine, can you turn the wheels easily?

If not, I suspect 2 problems.
A. Power stg pump going bad causing the whine if fluid level is ok and belt not slipping/ok.
B. Steering gear is leaking. Pitman arm seal are common to give out / leak especially on a vehichle that has sat up for a while.

Typically, when hydo boost is bad you have a rock hard pedal that takes more effort than normal to engage. The hydroboost takes the place of the brake booster in gas fired vehicles as the diesel does not produce a vacuum required for conventional power assisted brakes.

Just use gunk or another engine cleaner/degreaser to clean everything and the leak should be easier to spot.

 

[HookEm]

Could be a failing hose or fitting.. I've zip tied blue shop towels to the hoses before (to make sure they didn't get in the belts and such) on compact utility tractors, gone for a drive (or let it sit)... then come back and removed the towels one by one to find the hole in the hose, or which fitting was leaking.

I don't think the pressures are as high in the HMMWV, but never a good idea to try to find a hose or fitting leak "by hand" with hydraulics.. pressure can force the fluid into your skin causing all sorts of problems.

If you don't find any issues here, definitely check that the reservoir itself isn't leaking. I've seen cases where the cap lets it leak.

That's awesome advice. I'll do that tonight and see. A lot safer than being underneath while my wife is pumping brakes/steering!

 

[deathrowdave]

Shaft seals are cheap easy fix .

 

[juanprado]

Shaft seals are cheap easy fix .

I believe this has the Sheppard gear not the common Saginaw gear and parts are challenging.