Mechanics

MYSTERY COMPONENT USING FLUID

1999 Chrysler LHS

Steering problem
1999 Chrysler LHS 6 cyl Front Wheel Drive Automatic 160000 miles

Steering was normal turning right, but EXTREMELY difficult to turn left; followed by a 'squishing' noise, and then I had steering fluid all over my feet & pedals. Chilton manual shows no components that use steering fluid on passenger side of firewall -- nearest would be the steering gear. What fluid membrane has failed?
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Richie333
February 23, 2010.




I'm confused. Is the fluid on the passenger side or by the pedals? Sounds like the spool valve seal is leaking. It's at the end of the steering column next to the firewall. Parts are not available; you will need a rebuilt rack and pinion assembly and an alignment. Fortunately, remanufactured assemblies aren't very expensive compared to new ones.

Caradiodoc

Caradiodoc
Feb 25, 2010.
Thanks for your quick response.
Fluid leak occurred on driver's side pedals; soaked most of carpet on driver's side. Had checked fluid level in reservoir and topped up several days before. And, just before leak (and during), car made sudden & extreme jolting, directional changes (like into oncoming traffic lane) which I was able to correct; then no power assist in either direction.
By " spool valve", are you referring to the squeezable encasement surrounding the 2nd knuckle (inside the passenger compartment), going down the steering column towards the firewall?
In your opinion, what would be the best resource for a remanufactured rack & pinion assembly? (Sounds like a " pick-a-part" assembly from junk yard is not a good idea.)
Which manual would be best to tackle this repair?

Tiny
Richie333
Feb 25, 2010.
The spool valve is the valve assembly the steering shaft turns. It's in the rack and pinion assembly, and directs pressurized fluid flow to one side of the power piston or the other side to push the steering linkage in one direction or the other. This is not a common failure, so a salvage yard part isn't a bad option.

As a suspension and alignment technician, I replaced a lot of racks, but I only saw one other spool valve problem on a Chrysler product. That was on my mother's '95 Grand Caravan. It didn't leak, but it did the other things you described. GM had a real lot of trouble on their front wheel drive cars in the past. Chrysler, ... Not so much.

You might want to check into the cost of a remanufactured unit before heading to the salvage yard. Cost has come down a lot and many have improvements built in by the rebuilders.

Caradiodoc

Caradiodoc
Feb 26, 2010.
Thanks very much for your insight.
Would it be possible for you to elaborate, regarding the " improvements built in by the re-builders", that I might look for?

Tiny
Richie333
Feb 26, 2010.
In the 1980s, GM had a real lot of trouble with " morning sickness" with their front wheel drive cars. The symptom was lack of power assist in only ONE direction first thing in the morning. This would last from half a minute to many minutes until the fluid warmed up. Eventually the other direction would also be affected. The problem was caused by internal leakage of the highly pressurized fluid.

GM's fix for this problem was to replace the spool valve which included new seals. It was designed to get the car out of the 50,000 mile warranty. What happened after that, they didn't care. Very poor business practices as this is no way to look out for their customers. Yes, the new seals solved the problem, but everyone but the customer knew it wasn't a permanent fix.

The real cause of the problem was as the seals rotated when turning the steering wheel, they wore grooves into the soft aluminum housing. The grooves were causing the fluid leakage, not the seals. The old seals were worn just a very little bit, not enough to cause a problem on their own, so the new seals on the new spool valve were just big enough to seal for a few more miles. All GM wanted was for it to last another 10 - 15,000 miles to get the car out of waranty. After that, when the problem occurred again, the customer had to pay for repairs. Of course, then it was diagnosed correctly as needing the entire rack and pinion assembly. New spool valves and seals are not available for individual replacement anyway.

There was a 100 percent failure rate on GM front wheel drive cars, and a 100 percent second failure rate on those that received the new spool valves under warranty. Chrysler never had this problem other than the normal sporadic failure here and there, yet when any rack and pinion assembly is rebuilt, they receive the same treatment as the GM units.

Two aftermarket companies, Moog and Federal Mogul, in particular, bore out the aluminum housing with its grooves, then press in a stainless steel insert. The hard steel tube and the teflon-coated sealing rings will last forever. GM rack and pinion units in the salvage yards are sure to be remanufactured units with this modification, so the chances of getting one with a problem is low. It is very possible with a Chrysler rack to find an original that never developed a problem. My 1988 Grand Caravan has 217,000 miles and the rack is original. In fact, I've only replaced one $32.00 outer tie rod end so far in the entire steering and suspension system.

One common problem with Intrepid rack and pinions was squawking mounting bushings. They are riveted to the rack housing with rubber isolators in between. The rubber could dry out causing a noise when they flexed under the high pressure of turning the wheels. There were no repair parts available from Chrysler, and it wasn't a safety issue, just annoying. Spray lubricants would solve the noise for up to a few weeks, but the permanent fix was to replace the entire assembly. I don't know for sure, but I would bet the aftermarket rebuilders have come up with a solution. Aftermarket companies are real good at solving common problems like this, and their prices are not bad. That's why I suggested a rebuilt unit might be a better alternative for you if you plan on keeping the car. I still wouldn't be worried about using a salvage yard part, but you might be surprised at the little difference in price. Many rebuilt racks have lifetime warranties too although that would just cover the part, not the labor to replace it or for the alignment.

Caradiodoc

Caradiodoc
Feb 26, 2010.
Now in its sixth week, my saga continues.
I had my original rack rebuilt by a reputable auto parts company in Burbank, CA for $115.

I had difficulty determining what type of fluid to refill the system with. I know now that I should have used Chrysler's MOPAR Power Steering Fluid.

I first tried Dextron/Mercon, as advised by a local parts guy. After blowing the same seal again, and another rebuild, I tried ATF+4. Seals held, but power assist was non-existent. Rebuilt again.

Third times a charm? I used Chrysler's MOPAR Power Steering Fluid " works great at normal driving speed, but at idle, not so good. I followed all torque specs, and bled the system throughly after several transfusions to be sure system fluid was pure. Checked all tubing connections, etc. When running, there's a strong visible fluid flow through the reservoir.

Any advise at this point would be greatly appreciated, as I am stumped.

Tiny
Richie333
Apr 8, 2010.
Something doesn't seem right. The wrong fluid should not cause a new seal to leak or pressures to go too high. I wonder if there was some other problem that was overlooked.

If there is a variable assist valve screwed in near where the hoses connect, unplug its electrical connector and see if the power assist comes back.

Caradiodoc

Caradiodoc
Apr 8, 2010.
I tried unplugging the variable assist valve, and no change.

Even with the tires off the ground, there is significant drag (more than just the feeling of a fluid exchange through the steering gear) when turning the road wheels by hand.

After the most recent rebuild of the rack (when I first reinstalled it), there was some improvement during the " bleed" after reaching right turn stop, but continuing to left turn stop, any change was lost. Now when I attempt to " bleed" it, there is no change at all.

I'm looking again for leaks, or fluid level change.

Any insight or a next step to try would be most welcome.

Tiny
Richie333
Apr 9, 2010.
There are two possible approaches but both require a trip to the dealer. One step is to connect a pressure gauge between the pump and rack. A valve is closed momentarily to see how much pressure the pump is capable of producing. It should hit at least 1100 psi. If it can not, the pump is worn and must be replaced. Next, the pressure is observed when the valve is open but the steering wheel is not being turned. Pressure should remain very high. If it drops real low, internal leakage is taking place in the rack.

In nine years as a steering, suspension, and alignment specialist at a very nice family-owned Chrysler dealership, I only used that tool once, on an Intrepid from out-of-state. I can't remember what normal pressure was with the valve open, and I never did find the cause of low power assist because the owner had to head home. I DO know a new rack and pinion and a new pump did not solve the problem. All that left were the hoses and the variable assist valve and control module.

Your second step, the one I didn't get to, would be to use the Chrysler hand-held computer to access that variable assist module and operate it remotely to see if it responds. It is actually listed in a sub-menu under Automatic Transmission. Vehicle speed data from the transmission computer is one of the inputs to the variable assist module so it knows to provide more power assist at low speeds. This system caused so little trouble, I only remember replacing a few racks over the years. There are no common problems I can think of.

Caradiodoc
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Caradiodoc
Apr 9, 2010.
Thank you for your quick response.

I looked through my guages, and have nothing that can handle pressure anywhere near an 1100psi, so going to the dealership sounds like a good idea. The hand-held computer sounds interesting too. I assume the commercially available instruments wouldn't cut it.

Unfortunately, each the dealerships in my area have poor service reputations. In my own experience, I was billed $660 to have a fan belt changed. It took 2-1/2 days in the shop, during which I received zero communication from the service rep, and on my receipt was a notation that my charcoal canister needed to be replaced, for a price exceeding the current receipt " apparently they had used a " smoke sniffer" to determine this, in a test that took 4 to 6 hours). I figured that I must be paying for their (no doubt) 'exhaustive' investigation, so I asked if the rep, or the mechanic could show me where the canister was located on the vehicle. He told me that it was on the under side of the car, in the very center of the vehicle. Yeah.
But that's another story.

Since my last post, I raised the front end (roadwheels off the ground) and with the engine off (ignition key in the " on" position), I turned the steering wheel from left to right stop several times. Almost immediately, it became VERY easy to turn the wheel, with only slight resistance near the end of each run. I also noticed how much further the steering wheel could turn in both directions. I checked for leaks, etc. And all was ok. I started the engine, and right away it was like a heavy resistance had been added.

Could the variable assist module be stuck in the closed position (so that even unplugging it made no change)? If so, how would I go about getting it unstuck?

Tiny
Richie333
Apr 11, 2010.

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