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Power steering won't bleed. Wits end

I am curious why you say this. What information do you have about this?
I have been doing it for decades. And lots heavy truck manufacturers call it out for their steering systems. Paccar, International, Freightliner..
They say it right on the reservoir. ATF only.View attachment 422470

Even had several oil guys tell me that it works fine.
This is one of dozens around my work with dual steering boxes on 20K rated axles.
I thought this was a 1/2 ton Chevy tread? Always use OE recommended fluids. Have you seen a C/K5 manual that calls for anything other than PS fluid in THESE units?
 
I thought this was a 1/2 ton Chevy tread? Always use OE recommended fluids. Have you seen a C/K5 manual that calls for anything other than PS fluid in THESE units?
Sure, oe fluids are always recommended by the oe. But the general public has been using whatever they have on hand for decades. Guess what? ATF works fine for thousands of power steering pumps all over the world.
 
I’ve used everything from 80w90 to ATF in my personal rigs, I’ve found 15w40 to be a nice happy medium
 
Good ideas. For my next trick I will drop the drag link and try to bleed the box that way. At least that will save me from wearing out my new front end parts from turning back and forth so much, lol. And I do have an old cap now since my new pump came with a cap. Not sure it’s tight enough to hold vacuum but easy enough to try.
 
I thought this was a 1/2 ton Chevy tread? Always use OE recommended fluids. Have you seen a C/K5 manual that calls for anything other than PS fluid in THESE units?
Yes, this is about small trucks. Sometimes information crosses all sizes.
I asked what information you have as to why you said not to run ATF. I don't stick to the manual religiously.
Not trying to be a d!ck just asking what your reasoning is. I personally have used it for decades in my stuff.
 
personal experience with all of these trucks from yesteryear is that the power steering fluid vs transmission fluid... doesn't matter much? of the few parts I've had leak- they were on old beat up everything with many years sitting dry and many miles and hours of use. A few I had good results resealing, and others got new/rebuilt... never had a leak I could blame on "because the fluid is pink with extra detergent"

ive had new clean parts with clean PS fluid running through it, and try to maintain clean PS fluid in it added... also had a red / brown mud substance pumping through a couple trucks that got the "if it aint broke dont fix it" treatment...

had a M1009 with hydroboost- nice burnt smelling maroon colored fluid in it- had assumed the military was using old used transmission fluid to fill the steering - better than AIR or water- right??!

maybe it would be more critical to newer stuff, but I don't sweat the difference here.

newer electric assist columns? probably dont want to top off with ATF :D
 
Dropped the drag link after work to try bleeding that way, filmed the fluid in the pump with my phone and could see it rising and falling and what looked like bubbles popping, pockets of air escaping. Started feeling good about it. It even crested and spilled over a few times. Probably cycled the steering 40 times with the drag link off. Re installed drag link, cranked it and moved it around in my driveway. No change... F!@#$%G 0 difference. What the F is going on with this thing. Then I thought about what someone said about having some resistance on the wheels helping it bleed. Drove the truck down my street with the cap off the pump slowly turning all the way lock to lock. Nothing, no change. Still obvious aeration when I look at the fluid with it running. Im probably going to half to walk away from this thing for awhile. I have other more important projects and this F ing BS is wasting my time. Maybe I need to find a part out and buy the OEM box and pump off of it. F this.

Oh and I tried the vacuum trick, I actually have a PS bleeder attachment for my Vac pump but it won't work on GM with the cutouts for the cap in the pump body, won't seal. So I drilled an old cap and put a vac hose in it and it would hold vacuum with my finger over the hole but the cap wouldn't seal tight enough over the pump for it to pull a vacuum.
 
Definitely sucks for you. A break may be good for the old attitude.

I was saying that having just a little of the weight on the tires instead of completely off of the ground can sometimes help.
 
I was talking with a buddy about it tonight and he reminded me of twice when we had the steering apart chasing leaks on two of his trucks and when we put them back together for whatever reason we DIDN'T bleed the system whatsoever and never had a problem. I just have to believe something is wrong here. There’s no reason it shouldn’t have bled after all I’ve done.
 
… had a M1009 with hydroboost- nice burnt smelling maroon colored fluid in it- had assumed the military was using old used transmission fluid to fill the steering - better than AIR or water- right??!


Funny you should mention the cucv’s, if I’m reading this right the military actually specs out the use of ATF in the power steering system.

From the lubrication order.

185FDD21-AE15-403A-9000-CA9A87EA94DA.png
 
I had a very similar experience with my 89 Jimmy. Finally was able to get it bled with a mity vac capView attachment 422558
So that one has the 2 notches for these pumps and seals tight? I guess the better question is why is this necessary. Im wondering if the reason these are so difficult is because of the routing of the hoses, the way that they come straight up off of the box and make a loop that is higher than the fluid inlets in the pump, instead of making a 90 and running down underneath the pump and then up to it like the older squares.
 
Dropped the drag link after work to try bleeding that way, filmed the fluid in the pump with my phone and could see it rising and falling and what looked like bubbles popping, pockets of air escaping. Started feeling good about it. It even crested and spilled over a few times. Probably cycled the steering 40 times with the drag link off. Re installed drag link, cranked it and moved it around in my driveway. No change... F!@#$%G 0 difference. What the F is going on with this thing. Then I thought about what someone said about having some resistance on the wheels helping it bleed. Drove the truck down my street with the cap off the pump slowly turning all the way lock to lock. Nothing, no change. Still obvious aeration when I look at the fluid with it running. Im probably going to half to walk away from this thing for awhile. I have other more important projects and this F ing BS is wasting my time. Maybe I need to find a part out and buy the OEM box and pump off of it. F this.

Oh and I tried the vacuum trick, I actually have a PS bleeder attachment for my Vac pump but it won't work on GM with the cutouts for the cap in the pump body, won't seal. So I drilled an old cap and put a vac hose in it and it would hold vacuum with my finger over the hole but the cap wouldn't seal tight enough over the pump for it to pull a vacuum.

oooooooooooouch. sorry this is such a tough nut.


never been there- how far is north Carolina from southern CA? im guessing 1/2 tank of gas aint gonna cover the trip over for me and my plastic mallet to beat on your steering box with the non beer hand?????
 
oooooooooooouch. sorry this is such a tough nut.


never been there- how far is north Carolina from southern CA? im guessing 1/2 tank of gas aint gonna cover the trip over for me and my plastic mallet to beat on your steering box with the non beer hand?????
That would be what we call “a pretty good ride”
 
I have the idea to pull the return hose off at the pump end and pull a vacuum through it, once I have good fluid flow, plug it back onto the pump. Theoretically, wouldn’t that mean the box now had no air in it?
 

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