Power steering pumps dying instantly

[lanxer57]

The steering lines failed suddenly on grandpas 1998 K1500, and killed the steering pump. Replaced the lines, and steering pump, bled the system, and it worked... For about an hour before it started whining again, and became hard to turn. I tried removing the EVO, to no effect. I replaced the pump again under warranty, and this time it failed in under 5 miles, under 20 minutes. There are no bubbles, no foam, the fluid is holding steady at the correct level. I started it again, and it was noisy, but worked, until I got about half a mile, and it became hard to turn again. This was repeated twice. The pump that has failed twice is the "master pro 731-0125" remanufactured steering pump.

What am I missing? The gear box?

 

[evilunclegrimace]

If you did not thoroughly flush the box with copious amounts of P/S fluid it is entirely possible that the pump is failing due to metal contamination.

 

[sneakingfart]

I can think of several things. Number one, I am not sure what you mean by "the steering lines failed." As in, they catastrophically blew up, system ran dry, and pump died? How did you find out that the pump died? Did you replace the lines which then revealed a bad PS pump? Or did you empirically replace the lines and pump, only to have it fail in the timeframe you described?

In any case, this is one of two things: either A: you had two bad PS pumps from a low quality rebuilder (I know nothing about Master Pro other than it seems quite inexpensive), which is very possible, or B: you have something wrong with the steering gear. Just curious, can you take a sample of your PS fluid and see if there is any "glitter" or metallic particles in it?

I hate to tell you to replace the PS pump with a GM genuine pump, because it isn't cheap (about $400), without knowing more information, but I am leaning toward a low quality rebuild on the Master Pro pump. The problem is, if you have metal in your fluid, we have no way to know if it came from the initial breakdown, or the first bad PS pump. It's just very strange that it fails basically instantly...twice. That's why I am blaming the PS pump rebuild as the problem. Even if you have significant metal contamination, I would think the failure would be more gradual, not immediate. Still, vehicle control components aren't parts to save money on in my opinion.

Long story short, the way I would approach this, would be to check the fluid for metallic particles. If positive, I would be replacing the entire PS system (lines, the pump, and steering box). Because you have no way to know where the metal is coming from. If the fluid is clean, I would replace the pump with something better (GM genuine ideally), flush the system, and install a PS fluid in-line filter. This is basically what I did when I installed the Redhead steering gear. Entirely new system, with a GM genuine pump. This is my daily driver (and my kids only want to ride in this truck out of all our other cars), so it has to be safe and reliable.

 

[Road Trip]

Your problem description makes it sound like that the previously failed pump left
metallic debris behind in the rest of the your power steering system. And while
reply #3 would make for a guaranteed fix, I wonder if it's possible that by adding
the correct filter to the return side of the power steering pump if we could end up
with the replacement pump seeing virtually perfect clean PS fluid? This way you can
drive the truck, not trash the replacement pump, and in a reasonable amount of time
the entire system has flushed itself foreign object free?

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I really dislike whiny power steering pumps, and years ago I discovered that if I installed one of
these (along with a good fluid flushing at the same time) that a quiet new pump would remain quiet
for the remainder of the time I drove the vehicle. I'm almost at the point to where I wonder why these
weren't installed at the factory?

****

Anyway, instead of a complete PS hydraulic system replacement, what if you:

1) Replace PS pump. Instead of connecting the return line to the PS pump, leave the far end connected to the steering
box, dangle the open end into a catch pan, fill the reservoir, start the truck and turn the steering wheel lock to lock, hopefully
pumping the majority of the debris right out of the box and into the pan? Maybe budget for using a quart or 2 of (cheap)
PS fluid, hopefully being able to see an improvement and stopping there.

2) Now Install the Magnefine inline filter into the low pressure return line to the PS pump. Reconnect the line to
your new pump. This becomes the damaging debris gatekeeper, keeping whatever debris still lurking in your
system from contaminating your new pump?

3) With both front tires slightly off the ground, add fluid and proceed to burp all the air out of your PS system,
turning the wheels lock to lock several times while adding fluid as necessary until the fluid level stabilizes. NOTE: The
new fluid in the reservoir may be a bit aerated/foamy after all the excitement, but this should clear up after
sitting overnight.

4) Depending upon how much debris was in your system, you may be done at this point. On the other hand, in
an abundance of caution you may choose to replace this first filter with a new one after 1000 miles or so. (But
I would expect the 2nd filter to then last as long as the remainder of your vehicle.)

To recap, Reply #3 would be a guaranteed fix. But if you are in the situation where you just can't invest that
kind of money into a 100% brand-new (debris free) power steering system, maybe this could be a more affordable
repair strategy? Just a thought.

Best of luck --

 

[lanxer57]

In the initial failure, the hoses developed pinhole leaks (very suddenly, as there was no noticeable leak before). I tried topping it off, but it emptied in seconds. with an assistant turning the wheel, it looked like jets of fluid were coming out of the lines. I replaced the lines, and bled the system, only to find that running dry had, of course, killed the steering pump. The steering was always a bit "sloppy", where I have to turn the wheel about 1/8 turn left and right to keep it going forward, the total distance between these points being about 1/4 turn. Grandpa said he had most of the steering linkage replaced "except one link, because it was so expensive". I assume that that "link" must have been the gearbox. Cant hurt to replace it?

 

[CumminsFever]

Assuming there is no cooler or hydroboost in the system, the gearbox remains the only other part. If the rubber lines failed, it is possible there is a rubber chunk stuck somewhere.
Before attempting to find a good quality gearbox, I'd try using air to blow backward thru the system with the pump unhooked. That may clear out anything stuck in there. It is possible to have poor quality rebuilds on pumps, but it seems nearly impossible there would be 2 failing in such a short time and in exactly the same fashion.
The steering gearbox may be toasted, which will send you down the rabbit hole of trying to find a decent one.

 

[AuroraGirl]

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Heres an example of metallic debris in a pump

I had not seen this debris in the reservoir, or even changing the pump itself, the only way I saw this was when I removed the flow control valve off the rear of the pump. This pump was whiny and the shaft had actually very noticeable runout while turning. The pump also had no pressure at idle but it worked when it got gas.

Because of this I installed the exact filter @Road Trip posted and another used pump (which I had)


Your failure issues dont seem to match your implied reasons, and something that helps when trying to find an issue is to not give an issue a cause, then treat that cause . Use the symptoms to investigate a cause and to fix it. Then, verify the fix by ensuring the symptoms have been resolved.

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[AuroraGirl]

In the initial failure, the hoses developed pinhole leaks (very suddenly, as there was no noticeable leak before). I tried topping it off, but it emptied in seconds. with an assistant turning the wheel, it looked like jets of fluid were coming out of the lines. I replaced the lines, and bled the system, only to find that running dry had, of course, killed the steering pump. The steering was always a bit "sloppy", where I have to turn the wheel about 1/8 turn left and right to keep it going forward, the total distance between these points being about 1/4 turn. Grandpa said he had most of the steering linkage replaced "except one link, because it was so expensive". I assume that that "link" must have been the gearbox. Cant hurt to replace it?

the steering sloppy you describe could easily be the rag joint on the steering column, it could also be any of the mechanical linkages in your steering setup. It could also be the steering gear. I would not replace anything that doesnt need it and I have no discernable improved part on hand, if thats what you are asking.

 

[jd33173]

Roadtrip has a great idea and will give you some more info about whats actually happening. Swapping the pump(perhaps w a different brand) and letting it pump some fluid from the return into the catch pan, will provide info on whats really happening. You dont have to run it for long you just want some data. If you do get evil glitter, unplug the steering box and flush those lines.

Since your steering box sounds beat, swap that too. I did a new borgeson quick ratio box from summit and it has been great so far. While you are working on this, and since you said your steering is sloppy, either swap out your rag joint or go to the replacement shaft w the universal joint so you dont need it going forward.

There is a process for properly Bleeding the ps system, you need to have the wheels off the ground and go lock to lock quite a few times, i recommend you dowload the manufacturers service manual for your truck from this forum and follow the bleeding procedure to try to make sure you dont have any air in the system.

The filter sounds like a very good idea and i will be ordering one for my truck shortly(thanks Road Trip)

 

[EKOBS]

The steering lines failed suddenly on grandpas 1998 K1500, and killed the steering pump. Replaced the lines, and steering pump, bled the system, and it worked... For about an hour before it started whining again, and became hard to turn. I tried removing the EVO, to no effect. I replaced the pump again under warranty, and this time it failed in under 5 miles, under 20 minutes. There are no bubbles, no foam, the fluid is holding steady at the correct level. I started it again, and it was noisy, but worked, until I got about half a mile, and it became hard to turn again. This was repeated twice. The pump that has failed twice is the "master pro 731-0125" remanufactured steering pump.

What am I missing? The gear box?

I have had this happen to me on customer cars, these reman. Pumps can be really poorly rebuilt.