Power steering bleeding issues

[KallyLC]

My brother was driving the M1008 last week, and it blew a power steering hose. I don't know exactly how or why, but the hoses are probably 40 years old so it's not entirely surprising. He had to drive it about a mile or two back home after it blew and it lost a load of fluid.



I ordered some new hoses, we replaced them today and tried to bleed the system, and we can't seem to get it to work.

We followed the instructions from the TM, that seem to be echoed online by various people. Jacked the front end up, put it on axle stands. Filled up the resevoir and started the engine, turn the wheel from lock to lock over and over. The TM says to press the brake pedal while turning the wheel, other places do not, we tried it both with and without. The fluid level went down a little bit, but not significantly, and the steering and brakes are still rock solid with no assist, it won't bleed.

With the reservoir being kinda buried under the alternator it's difficult to see into but there's no foam or obvious bubbles coming up out of it while we're trying to bleed it. The pump is not making any suspicious noises, and there are no leaks anywhere.

While we were scratching our heads, I was looking up info on various forums to see if anything might help, and I saw a suggestion that the hydroboost could be bled by removing the low-pressure return line and letting it pump into a bucket. I unhooked the return line and we started the truck, and barely anything came out, just an incredibly slow trickle of fluid.

I don't know if it is working but it just takes a while and we just got impatient, or if the pump's bad and isn't actually moving any fluid. What could be the issue?

 

[Barrman]

If you are just getting a trickle from the return then either a restriction somewhere or a bad pump might very well be your issue.

Also, I have always done the wheel lock to lock in the air with the engine off to bleeding the system. Should work either way I guess.

 

[RattleSnack]

If you are just getting a trickle from the return then either a restriction somewhere or a bad pump might very well be your issue.

I agree with Barrman.

Another possibility is the pressure relief valve in the pump is faulty. That could of been why the hose blew. It's either that, a restriction somewhere, or the pump is shot.

 

[KallyLC]

My brother was driving at the time, he says he had it at full lock and bumped a curb or something, but who knows.

I ordered a replacement pump with the lines just in case, so I'll get that swapped over. Shame I didn't have the foresight to order the tools to remove/install the pulley, too.

 

[RattleSnack]

My brother was driving at the time, he says he had it at full lock and bumped a curb or something, but who knows.

I ordered a replacement pump with the lines just in case, so I'll get that swapped over. Shame I didn't have the foresight to order the tools to remove/install the pulley, too.

Ah yes...the ol' "half-truth-story" from your brother/son/buddy etc.!! We've all been there before...and you'll probably never find out the whole story.

Anyways, you can always rent a PS puller from O'Reilley's, Advance Auto, or Autozone.

 

[KallyLC]

There's none of those this side of the atlantic, unfortunately. I ordered one that should hopefully fit, and it should be here this week.

 

[RattleSnack]

Oops!....I didn't notice your location. My apologies!!

 

[Sharecropper]

Remember that the bracket must be on the shaft before the pulley is pressed on. Duh! After you reinstall the pulley onto the new pump, temporarily mount the pump back in its place, tighten the nuts, and then check for pulley alignment. The pump is driven off two belts, one of which is the same belt that drives the drivers side alternator, so make certain that you align the PS pulley with the alternator & crankcase pulley. If not aligned, you will go through belts over & over. There is a proper sequence to tightening all three belts. There are two nuts which must be loosened to adjust the passenger side alternator, three nuts for the drivers side alternator, and four nuts for the PS pump. I documented the replacement pump in post 275 of my rebuild thread https://www.steelsoldiers.com/threads/kinda-got-carried-away-m1028-rebuild.54469/post-2182661 . I also documented the process for aligning the pulleys in a separate thread Squealing Belts - and How To Fix Them | SteelSoldiers . Hope this helps.

 

[KallyLC]

Thanks, I will keep the advice for replacing the pump in mind but it seems we may not need it. I'd read that letting it sit overnight helped, and sure enough my brother tried it again this morning and he's been able to bleed it and get it working normally now.


He hasn't said it's making any unusual noises but I still don't know if running the pump dry has hurt it, if it does need replacing in future then I've got the parts and tools to do that at least.

 

[nyoffroad]

Thanks, I will keep the advice for replacing the pump in mind but it seems we may not need it. I'd read that letting it sit overnight helped, and sure enough my brother tried it again this morning and he's been able to bleed it and get it working normally now.


He hasn't said it's making any unusual noises but I still don't know if running the pump dry has hurt it, if it does need replacing in future then I've got the parts and tools to do that at least.

Don't you love it when they fix themselves?