intermittent power steering failure

cockerpunk · 10-21-2015, 04:35 PM

the symptom of this problem is that while driving down the road, sometimes i have power steering and sometimes i dont. literally mid corner, mid turning of the steering wheel, i can feel it get tougher and easier, like a switch being turned on and off. its pretty random, not associated with any one wheel position or engine RPM or anything, it just comes on and off.

so earlier this year i had a battle with my power steering rack, i bought a cheapo one, guaranteed to work, and 3 racks later i got one to kinda not leak that badly. the high pressure line was replaced 2 years ago. and in the middle of the steering rack fiasco earlier this year, they kept telling me it was my low pressure lines, collapsed. so i ended up replacing them too. the last line that wasnt replaced was the tank to pump one, which i just did tonight, and that didn't fix it.

i think air is getting into the system. but im not sure where. the pump doesn't make any noise, it seems to be fine. plus its not like the pump is going on an off randomly right? oh, replaced the belt too. and the rack leaks, somewhat, but thats not new. but otherwise the power steering system is basically brand new.

and ideas?

Lapkritis · Lapkritis's Garage

What fluid are you using? I had a mk2 gti that the would do the same with random belt slip. The pulley was out of alignment and the belt only had pressure on one side of the pulley channel. In the rain, it would go out if I was following too close to a car in front (road spray) but otherwise fine.

JonA · 10-22-2015, 07:39 AM

Same problem here. I rebuilt the rack 3 years ago and it has done it since. Thought it might be air somewhere but after multiple attempts to purge, not so sure. Maybe dirt? But I was very careful when reassembling. The old resevior had a lot of crud on the bottom and was replaced but maybe some of that inadvertently got into the new rack. I am very certain the belt is not slipping and the pump is quiet and happy. Don't know. Not real anxious to take the rack apart again so I have been living with it.

Jon

944 Ecology · 10-22-2015, 11:43 AM

Bad rack.

cockerpunk · 12:21 PM

yeah im suspicious of the valves in the rack. it was a cheapo rebuilt rack.

i do not think its the belt slipping. at no point does the system make noise, and the belt is new and tight.

recommendations on rebuilt racks that actually are good? prefer to not have to buy the 1600 dollar ZF rebuilt one ... 944online has one, pelican here has one rebuilt by atlantic ...

Lapkritis · Lapkritis's Garage

I'm probably in the minority but I would cut it all out and put bolts in the holes. Manual. "There, I fixed it."

cockerpunk · 10-23-2015, 02:15 PM

i did that this spring, and it wouldnt be a problem, except that my driveway REQUIRES at least a 3 point turn, and there is no cheating, its surrounded by retaining wall, no putting a wheel on the grass and calling it good. i didnt even just plug all the wholes, i short circuited one side of the piston to the other, so it was a true manual rack.

on the road, it was great without power steering, getting it in and our of my garage was simply terrible.

anyone have any recommendations on a rebuilt rack? anyone have any in the sub 500 buck range that 99% are good? cause im tired of installing and reinstalling steering racks, ive already done it at least 6 times this year.

JonA · 10-24-2015, 06:05 AM

Rebuilding a rack is messy but not difficult and the kits sell for about $70.00. I'd find a good used rack somewhere and rebuild it. This forum is full of stories of failed racks from the parts suppliers. You're gonna do it with a lot more love and care.
Most of the work is getting them in and out and you must be real good at that by now......

Good luck,
Jon

cockerpunk · 10-25-2015, 04:47 PM

Quote:

Originally Posted by JonA

Rebuilding a rack is messy but not difficult and the kits sell for about $70.00. I'd find a good used rack somewhere and rebuild it. This forum is full of stories of failed racks from the parts suppliers. You're gonna do it with a lot more love and care.
Most of the work is getting them in and out and you must be real good at that by now......

Good luck,
Jon

i think the problem is the pressure valves in the rack, which are not in he rebuild kit.

JonA · 10-26-2015, 03:38 AM

Correct, the rebuild kit is just all the seals. My suggestion was to get a good used rack from somewhere. It would make good sense to rebuild that rack before installing so you would not be looking at a leaking rack 6 months down the road.

Jon

p-talk · p-talk's Garage

My 0.02 . . .

Your problem could also be a collapsed feed hose from the PS reservoir to the pump. Mine was collapsed, and made my car feel like I had "partial" power steering. When I replaced this hose, along with the reservoir, all was well with my PS system.

As for rebuilt racks, the vintage Audi folks swear by a shop named Jorgen, who also carries rebuilt 944 steering racks that are inexpensive with a solid warranty - Steering gears and steering gearboxes, rack and pinion steering gears and more.

grendiers · 10-26-2015, 08:27 AM

Hey Barry, sounds like a good tip, I've been following this topic as it applies to my car! My '88 924S SE, has a rebuilt rack, and the power steering works fine when first driving the car. As the miles pile up, the power steering is non-existent, and tough to turn when parking for example. Dave.

p-talk · p-talk's Garage

I hope this helps folks figure out their PS systems with less headache. I had recently replaced my steering rack as well, and was concerned I had a bad rack because of similar symptoms. But on my visual inspection of the PS system, I had missed this hose as it routes around by the fan shroud and is hard to see until you remove it. Once removed, it was obvious that my hose was CLEARLY collapsed and restricting flow.

This is the article I found during my own troubleshooting search that led me to the solution for my system: PS issues. Is it the rack?

Quote:

Originally Posted by grendiers

Hey Barry, sounds like a good tip, I've been following this topic as it applies to my car! My '88 924S SE, has a rebuilt rack, and the power steering works fine when first driving the car. As the miles pile up, the power steering is non-existent, and tough to turn when parking for example. Dave.

cockerpunk · 10-26-2015, 11:47 AM

Quote:

Originally Posted by p-talk

My 0.02 . . .

Your problem could also be a collapsed feed hose from the PS reservoir to the pump. Mine was collapsed, and made my car feel like I had "partial" power steering. When I replaced this hose, along with the reservoir, all was well with my PS system.

As for rebuilt racks, the vintage Audi folks swear by a shop named Jorgen, who also carries rebuilt 944 steering racks that are inexpensive with a solid warranty - Steering gears and steering gearboxes, rack and pinion steering gears and more.

all hoses have been replaced.