Power Steering - Gradual Loss

[RobertISaar]

and now i get to eat my words about the GP not becoming FAILbus in the last few days...

 

wife was driving(i was not present), apparently lost power steering assist at one point(keep in mind i don't have the whole story yet), stopped, after 25 minutes of me explaining how to check and add power steering fluid(engine was off during this), she eventually manages it, and all of a sudden the assist is back, YAY!

 

a couple minutes later, assist disappears gradually, she was limping it back home, her father came and drove it the rest of the way, same situation, had full assist for a while, pump starts making a growling noise and assist starts bleeding away.

 

now it back at la crapshack, so i do a few preliminary checks(turns out the belt tensioner is shot as well, which is a recent development , but it seems to be supplying enough tension to keep all of the pulleys turning, so i will disregard for now), and i took the cap off of the resivoir, saw some foaming bubbles and a somewhat lower than normal fluid level, waited a few more minutes, no more bubbles and fluid level is good again.

 

so, start engine with cap off, move steering wheel, seems perfectly fine, moved it from lock to lock about 20 times, full assist.

 

put the cap back on, tried turning wheel, pump is screeching and assist is going away (parked during this whole time), so shut off engine, look quickly at resivoir, VERY low, and air bubbles are almost a constant stream, fluid level slowly coming back up to normal.

 

at this point, i was thinking "cap off, all is well", so i drove it like that around the block, first turn, pump noise, but full assist, second turn, more noise and losing assist, third turn, less assist, fouth turn, pretty much manual steering.

 

so, it seems i threw the cap on at the same time assist was going away as a coincidence rather than a clue.

 

 

 

any ideas as to what decided to kill itself today? or anything else to do to determine what the issue is?

 

 

 

also, father-in-law pointed this out, we were both unsure of it: the tie rod boots, when the steering wheel is perfectly straight, are they supposed to get all bent up? he said they straighten out when the wheel is turned in the correct direction, but it seemed like it may give another clue.

[BXX]

Bubbles are due to a restriction or more likely pump cavitation.

 

Without pressure gauges hooked up, your gonna have to start replacing parts, starting with the most likely cause, the PS pump itself.

[RobertISaar]

does the fact that the fluid level SLOWLY rises back to normal(with bubbles) after engine shutoff point toward any one specific part?

 

and i've been looking online at all of the chain stores that are around, do none of them sell power steering pressure guages?

 

and IIRC, i was going to pull the pump before but something was stopping me from doing so...

[Schurkey]

does the fact that the fluid level SLOWLY rises back to normal(with bubbles) after engine shutoff point toward any one specific part?

Defective (ballooned) hoses that absorb fluid volume under pressure, and return the fluid to the reservoir when the pressure is relieved. The hoses are one step away from bursting?

 

 

and i've been looking online at all of the chain stores that are around, do none of them sell power steering pressure guages?

I'd AT BEST expect them in the rent-a-tool section. Not a popular or inexpensive set-up.

This is as cheap as I've ever seen a PS gauge system. Missing a lot of the functionality of a professional system, too.

http://www.etoolcart.com/powersteeringpressuregaugehoftu22a.aspx

Edited April 9, 2011 by Schurkey

[RobertISaar]

Defective (ballooned) hoses that absorb fluid volume under pressure, and return the fluid to the reservoir when the pressure is relieved. The hoses are one step away from bursting?

 

we were specifcally watching for this actually, but didn't see it... then again, there is a whole lot of unvisible surface area.

 

my father in law dealt with a taurus that did the exact same thing, lines would swell, lose all power steering gradually, low fluid level that would slowly return...

 

he ended up replacing the rack (and one of the lines that eventually exploded), problem solved.... i just don't want to invest the time and money into doing so without being absolutely certain that's the problem.

[RobertISaar]

ok, likely to be the last post before buying stuff...

 

just let the GP sit overnight, then had the wife start it while i was watching the resivoir, my notes:

 

at startup, a couple of bubbles slip up, but quickly goes back to just fluid returning. level drops SLIGHTLY.

 

once wheel starts turning, level drops as expected.

 

for a while, when the wheel is turning, level slowly drops with every turn until i can just BARELY see a little channel that sticks up from the bottom of the resivoir, this may be related to my fluid level though, but i certainly don't see any "whirlpool" effect that i would expect to see if the pump is drawing fluid and the level was VERY low. still no kind of bubbles at this point.

 

pump starts to growl and now air bubbles are popping up VERY rapidly and in large volume on the side of the resivoir that is closest to the firewall, mostly on the half that is closest to the belt. at this point, the fluid level was nearly bottoming out, so had wife straighten wheel and kill the motor, it was making a hell of a noise and was effecting the idle quite a bit(enough to make the motor rock in it's mounts), i was concerned about blowing up the hoses at this point, though i could see no swelling occur.

 

as expected, fluid level returns to normal slowly with a whole lot of tiny air bubbles along with it. i was also squeezing the little rubber section on the return hose that sticks out of the pump, was easy to compress, if that means anything.

 

 

 

since it seems that the pump works normally for the first ~2 minutes of runtime, then the continually dropping fluid level never gets close to actually draining the resivoir before returning to bad behavior, i'd like to think the pump is not the issue, especially since it seems the pump is continually supplying more than enough flow/pressure to swell up the lines(even though i can't visually confirm this), so it looks like the rack is our problem.

 

any other thoughts/warnings/facepalms before this trigger gets pulled?

[RobertISaar]

update:

 

car is shitpile, but it now turns correctly. i need to play with the alignment when it's not raining.

 

summary of events of last night: pulled rack without much trouble, took ~2 hours going rather slow(PRO-TIP: loosen/remove top power steering fitting BEFORE dropping subframe, otherwise, you may not be able to reach it). made the mistake of pulling on the rubber boot that hides the steering knuckle(?), could NOT get that back into the firewall for ~90 minutes, said fuck it, went on without it. top PS line couldn't be dealt with when subframe was lowered, so that was put on hold until the subframe went up.

 

rest went fairly smoothly after that, filled PS system, bled by engine off, steering wheel lock to lock about 20 times, started, pump was making horrible noise, but as i turned the wheel with the engine running, it quieted down and power assist was functioning, working beautifully. drove around town for about 5 minutes, and in the last minute or so, assist was intermittent(was full-on a few minutes before), so went home. LOST all assist as coming into driveway.

 

lifted front end of GP, and for the next hour or so, engine off, wheel back and forth lock to lock, and the ENTIRE time, whole lots of air bubbles, but power steering fluid level didn't drop during all of this.... so went and spent $50 on new power steering pump from the vatozone, got home, had it installed in a couple of minutes(line wrenches FTW), did lock to lock bleed procedure, after 5 minutes or so, no more significant bubbles, so start engine, assist is kinda intermittent, keep turning wheels, gets to where it should be, and STAYS functioning, so drive around town for a few minutes, making squiggly lines in deserted parking lot, seems to work alright, go home, all is well.

 

popped hood, removed PS resivoir cap, a little bit of smoke came out??? fluid level was down just a little bit as well, but since there was still air in the lines when it was started, i expected it. i'll have to check it out again when wife gets home from work.

 

 

 

so, the rack itself WAS a problem, did it being bad for the ~20 miles it was driven like it was cause the PS pump to shit the bed as well? considering how well the assist was working immediately after the new rack was put on, i'd like to think it was still at least somewhat functional at that point, since fluid level dropped noticably when the engine was running, as if it were pumping large amounts of it.

[Galaxie500XL]

Bad pressure hose? I'm wondering if the hose is damaged internally, and blocking fluid flow...would cause the symptoms you describe. The restricted line would raise P/S pump pressure through the roof, leading to pump failure.

 

Just a guess....

[RobertISaar]

we had considered this, and the pump even made the lines swell somewhere out of sight, but we're still running the factory lines, and by all measures the PS system seems to be working properly now.

[Jonpro03]

I've heard that running a pump dry will ruin it.

[virtuetovice]

You heard correctly.

[RobertISaar]

it never went dry....

 

low at times, but the pump never sucked air that i know of.

[RobertISaar]

ok, alignment is finish, over a 63" by 24" distance, there is less than 1/8" difference between the front and rear of the tires.... i'd calculate the angle on that, but it's far closer than any other alignment that's been done on the rustbucket... the steering wheel is also perfectly straight when going down the road, which is the first time that's happened in the last 15,000 miles at least.

 

pump whines a bit at all times..... kinda scares me. always has full assist, but occasionally when turning, it likes to vibrate the steering wheel a bit, which is also concerning...

[BXX]

You replaced the rack and PS pump, but didnt spend the $50 on both new lines:think:

 

The lines are prolly collapsing causing a restriction, hence the pump whining. A whining pump indicated pressure way too high or pump cavitation due to poor flow, both of which will destroy the new pump.

[RobertISaar]

presumably, the feed line swelled when the rack took a shit, why would either line collapse with a functioning rack?

[BXX]

presumably, the feed line swelled when the rack took a shit, why would either line collapse with a functioning rack?

 

If one line is restricted, the other will collapse, causing hell on the pump.

 

A restricted rack will do the same,

[RobertISaar]

lifetime warranty on pump, so if it does die before we get rid of this heap, i'll spend the 20 minutes it takes to swap them and deal with the lines then.

[Schurkey]

presumably, the feed line swelled when the rack took a shit, why would either line collapse with a functioning rack?

If the feed (pressure) hose swelled noticeably, the internal fabric reinforcement is torn, and the hose is one step away from rupture. If the return hose swelled--and I don't know how that would happen--same deal. The hose is damaged and ready to pop.