M1123 power steering aerated-Need troubleshooting advice

[kungflu72]

Well I have been having some issues with my 1123 power steering system the last few months. It is an 03 with the remote reservoir, and mile marker hydraulic winch. It has always had the normal power steering low whine. No big deal, its a HMMWV. It began whining more, and I noticed the fluid had a pink tint to it. Swapped out fluid and filter. Same thing almost immediately. So I decided to swap out the PS pump. Put in fresh fluid, bled as per the TM. No joy!
So now I started leaning to a suction side leak letting air into the system. I cannot see air bubbles in the remote reservoir, like when bleeding. But this is still my diagnosis. I am thinking enough entrained air to turn it pink. Anyhow, I swapped out all the low pressure hoses, fresh fluid (again) Bled as per TM (again). Immediately the same condition. The longer it runs and gets up to temp, the worse it gets.
My next move was to remove and bypass the PS cooler. Same result as before. I have searched many of the threads on here relating to PS trouble on the HMMWV, and couldn't really find exact symptom diagnosis. I know there is enough knowledgable guys on here to point me in the right direction. But here is what I am thinking:

1. Remove every high pressure hose and inspect/swap out O-rings
2. Buy a PS analyzer from Midwest Military
3. Troubleshoot with analyzer as per TM-Hopefully will reveal if there is an issue with steering gear or hydroboost
4. Last ditch effort will be just swap out hydroboost, then steering gear.

There is no external leaks whatsoever. Except for when it vents out the remote reservoir into the air intake. I do see fluid there from overflow. (I first thought I had the dreaded vampire) I really didn't think air could get in the high pressure side, because of an O-ring. I would have thought it would leak out. But reading through some threads, it is possible. Apologies for the long post, but I didn't want to hijack another thread. Any pointers would be appreciated from the Guru's on here. Semper FI!

 

[juanprado]

What fluid are you using?

Correct fluid is dexron 3 atf which is pink.

Bad hydroboost = hard brake pedal with no power assist.

 

[NDT]

You are on the right track. I would bypass the winch, if no change, I would look at the steering gear before the hydoboost.

 

[kungflu72]

What fluid are you using?

Correct fluid is dexron 3 atf which is pink.

Bad hydroboost = hard brake pedal with no power assist.

I am running DEX 3 in my rig. The fluid looks milky after running it for a bit. I first thought there was water intrusion in the system. But there is no place to cross contaminate the PS system that I am aware of. The PS cooler is a small unit that bolts onto the bottom of the radiator/oil cooler. And I have changed the fluid several times.
This is what the fluid looks like when I drain the remote reservoir. But you are correct, DEX 3 is a pink color.

 

[kungflu72]

You are on the right track. I would bypass the winch, if no change, I would look at the steering gear before the hydoboost.

I'm hoping for a simple/cheap fix for it! Steering gear is the most expensive part of the system. But I tend to agree with you. After it sits for a while, after start up. The brakes work flawlessly. It isn't until it runs a while and gets up to temp that the PS pump whines something awful. After that steering gets crappy. But the braking also loses it full function also.
I'm going to look at all the high pressure lines & O-rings. I'll follow your advice and bypass the winch circuit also. Appreciate the advice!

 

[juanprado]

There is a bypass tube for the winch for emergencies. I used to have a bunch but sold out. See if you can find one to check your system with out winch but I really doubt that is the issue. On epay occasionally.
I am leaning to the power stg pump as your culprit.
PS analyzer is just a pressure gauge to verify flow output. Civy ones are the same thing.
My experience with hydroboost is they work or they don't (leak or hard pedal) .
The power stg cooler is independent of the radiator so no cross contamination. Zep & others makes a can of transmission cooler flush if you can find to flush pwr stg cooler.

https://www.oreillyauto.com/detail/c/kooler-kleen/oil--chemicals---fluids/maintenance-chemicals/steering---transmission/transmission---cooler-flush/351c50fa93de/lubegard-kooler-kleen-transmission-cooler-flush/lbg1/19001/v/a/128213/automotive-car-2014-honda-civic?pos=2

 

[kungflu72]

There is a bypass tube for the winch for emergencies. I used to have a bunch but sold out. See if you can find one to check your system with out winch but I really doubt that is the issue. On epay occasionally.
I am leaning to the power stg pump as your culprit.
PS analyzer is just a pressure gauge to verify flow output. Civy ones are the same thing.
My experience with hydroboost is they work or they don't (leak or hard pedal) .
The power stg cooler is independent of the radiator so no cross contamination. Zep & others makes a can of transmission cooler flush if you can find to flush pwr stg cooler.

https://www.oreillyauto.com/detail/c/kooler-kleen/oil--chemicals---fluids/maintenance-chemicals/steering---transmission/transmission---cooler-flush/351c50fa93de/lubegard-kooler-kleen-transmission-cooler-flush/lbg1/19001/v/a/128213/automotive-car-2014-honda-civic?pos=2

So you believe my PS pump is the issue? I put a brand new one on when it began acting up. I realize that new-old stock part can be bad. But I experienced the same symptoms even after the new pump was installed. Do you have any info on the bypass tube for the winch? PN? I searched the interweb and didn't come up with anything. Appreciate all the help!

 

[Coug]

If you're getting air into the system, everything in the system is pressurized except for the pump reservoir/seals. Even the return to the reservoir is going to have positive flow. Something would have to be seriously wrong with the system in order to get air into it anywhere else, to the point where your system probably wouldn't be working at all.

The milky look could be some moisture that was still in the system from before you changed out the pump. Short of draining and flushing the entire system I don't know how else you will get moisture out.

Your picture doesn't look aerated to me, just milky, so I'm more of the idea that it needs flushed.

 

[kungflu72]

If you're getting air into the system, everything in the system is pressurized except for the pump reservoir/seals. Even the return to the reservoir is going to have positive flow. Something would have to be seriously wrong with the system in order to get air into it anywhere else, to the point where your system probably wouldn't be working at all.

The milky look could be some moisture that was still in the system from before you changed out the pump. Short of draining and flushing the entire system I don't know how else you will get moisture out.

Your picture doesn't look aerated to me, just milky, so I'm more of the idea that it needs flushed.

Appreciate the response. I have pretty much drained and flushed the complete system several times already. I was initially thinking the same as you. Water in the system. But after each drain or bypassing the PS cooler & rear diff cooler, it would immediately look just the same. I'm not sure what volume is in the system totally, but I would imagine 2-3 quarts. I've swapped out 2-3 gallons of fluid. Its not a really complicated system. That's why it has been so frustrating!
I have highlighted what I have bypassed so far in my troubleshooting. I'm going to work on bypassing the winch next.

I was thinking about rigging up a temporary remote reservoir, and connecting the PS pump suction to it. I would hook a hose to the actual reservoir, and run it to a bucket. Something like this:

This would replace all the fluid in the system. I'm still leaning towards air entrainment though. But at this point, I'm game for any solution to get me back on the road.

 

[Retiredwarhorses]

I’ve seen a bad flange “cracked” flange on hydor booster blue line cause this issue, no visible fluid, changed out o-rings, the flange was cracked from being over tightened. Unfortunately you will need to check every o-ring and every flange connection in the PS system.

 

[kungflu72]

I’ve seen a bad flange “cracked” flange on hydor booster blue line cause this issue, no visible fluid, changed out o-rings, the flange was cracked from being over tightened. Unfortunately you will need to check every o-ring and every flange connection in the PS system.

Super appreciated! This was the kind of info I was looking for. As stated in my first post, that was my next step in the troubleshooting process. I never considered a cracked flange connection. I was really thinking the O-rings. But I will go through each connection, one by one. It will take some time for sure. But cheaper than steering gear or hydroboost! One other question. Should I consider the hydraulic winch flange connections? Would they be constantly under system pressure, even when not being operated?

 

[mountainman68]

Did you ever figure out if you where getting air in the system?

 

[Mogman]

Did you ever figure out if you where getting air in the system?

Welcome to the SS forums!

 

[kungflu72]

Did you ever figure out if you where getting air in the system?

Sorry for the delay. Been really busy lately. I actually had 2 things going on with the system. Several of the o-rings on the high pressure hoses had hardened and just not sealing. I changed every one in the system. I also had a self inflicted leak on the main suction hose for the PS pump. I didn’t tighten the clamp down well enough. So a couple of 2 cent o-rings and a loose hose clamp. System is the quietest I have ever driven in all my years running these trucks. These guys on here are a wealth of knowledge!! Much appreciated for everyone’s input.

 

[Megalug]

Sorry for the delay. Been really busy lately. I actually had 2 things going on with the system. Several of the o-rings on the high pressure hoses had hardened and just not sealing. I changed every one in the system. I also had a self inflicted leak on the main suction hose for the PS pump. I didn’t tighten the clamp down well enough. So a couple of 2 cent o-rings and a loose hose clamp. System is the quietest I have ever driven in all my years running these trucks. These guys on here are a wealth of knowledge!! Much appreciated for everyone’s input.

Thanks For following up!

Experiencing the same problem. Care to share the size of the o rings or link of where you purchased.
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[Retiredwarhorses]

Sorry for the delay. Been really busy lately. I actually had 2 things going on with the system. Several of the o-rings on the high pressure hoses had hardened and just not sealing. I changed every one in the system. I also had a self inflicted leak on the main suction hose for the PS pump. I didn’t tighten the clamp down well enough. So a couple of 2 cent o-rings and a loose hose clamp. System is the quietest I have ever driven in all my years running these trucks. These guys on here are a wealth of knowledge!! Much appreciated for everyone’s input.

Usually what is is…the o-rings can have you chasing your tail, any time a fitting is removed I replace them.