Rack and Pinion blowing seal

Tiny
CARLUVR
  • MEMBER
  • 1989 PLYMOUTH RELIANT
  • 2.5L
  • 4 CYL
  • FWD
  • AUTOMATIC
  • 180,000 MILES
Hello,
We are having some serious problems with the replacement of the rack and pinion. We have replaced the rack and pinion three times and still not having any luck.
The first one, the holes were too big for the bolts and did not line up properly
The second one, when we tried to bleed it, the seal blew and we had leaking.
The Third one is doing the same as the second and when my dad has tried to start it over to prime, the steering wheel shakes badly from side to side.
Do you know what we need to do?
Has there been a modification in the way the rack and pinion is manufactured in the last ten years?
What can be done about the holes being too big? I wish there were a way my dad could call you.
Thursday, January 5th, 2017 AT 3:04 PM

8 Replies

Tiny
MHPAUTOS
  • MECHANIC
  • 31,938 POSTS
If it is blowing oil seals the internal pressure is too high and you may have a pump problem, as for the bolt problem, make sure it is for your exact model, racks can alter from model to model with minor changes that are not readily visible at first.
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Thursday, January 5th, 2017 AT 3:39 PM
Tiny
CARLUVR
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How would we check to see if the internal pressure is too high?
Which pump are you referring to, (my dad is not right here and I want to be able to pass the correct information on)?
How would we check the pump?
The numbers have been the same for the one that was put on years ago and when they put all of the car info in, that is the one that comes up.
Do you happen to know any reputable mechanics in Memphis, TN?
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Thursday, January 5th, 2017 AT 3:44 PM
Tiny
CARADIODOC
  • MECHANIC
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What holes are you referring to? The two on the driver's side that bolt it to the cross member? There is going to be some clearance between them and the bolts. You do not want the threaded part of the bolts holding the rack from sliding back and forth. That would cause the holes to wear even more and you would be constantly correcting the direction of steering. Rather, it is the clamping forces of those two bolts that hold the rack in place. The two bolts on the passenger side do even less. The rack housing sits inside a rubber gasket that allows it to expand and move sideways a little. Those bolts are just there to hold the rack in position.

Chrysler has always been known for good parts interchangeability between years and models. The same steering gear might have been used on newer models, but with larger mounting bolts, and therefore, larger bolt holes. Rather than try to keep a lot of similar but different part numbers in stock, they would just rebuild the one that can be used in the most applications, or they may have drilled out the mounting holes so that part could be used on more applications.

Which seal is leaking? If the steering wheel is oscillating back and forth, it sounds like you have the high-pressure and return hoses switched. On everything I am familiar with, those two ports are different sizes, but I know there were some that were the same.

Be sure there is nothing blocking the return line to the power steering pump. If you disconnect that hose at the pump, you can drop the end down into a bucket, then run the engine for a few seconds. Fluid should pump into the bucket fairly quickly. Do not run the pump too long when it is empty. Doing so will overheat the front seal, then you'll be replacing that too.

Many rebuilders supply their rack and pinion assemblies with a filter that is supposed to be slid into the return hose for their warranty to take effect. If that was done previously, it may be plugged from metal chips.

The modifications you asked about was an issue with GM front-wheel-drive cars in the late 1980's and early 1990's. They had a real common problem we called "morning sickness" because when the power steering fluid was cold, usually first thing in the morning, you would experience loss of power steering assist in only one direction. If ignored, it affected the other direction weeks or months later. This was caused by the teflon sealing rings grinding into the soft aluminum housing and creating grooves that let the pressurized fluid bypass the power piston. The modification that all aftermarket rebuilders performed was to bore out the housing, then press in a stainless steel sleeve that was hard enough to withstand that wear from occurring. GM's fix was to ignore the cause, those grooves, and replace the spool valve with its new teflon rings. That was well-known to be a temporary solution, and was intended to get the car out of the 50,000-mile warranty. After that, when the problem occurred again, and it did on every car, it was the owner's responsibility to pay for the proper repair.

Morning sickness could occur on any car brand or model, but except for GM products, it happens to a very low percentage of cars. Still, when any rack and pinion assembly is sent back to be rebuilt, almost all of them get the stainless steel insert to insure that never happens to their products.

One more thing that should not be overlooked is rebuilt racks come with plugs in the ports to keep dirt out. Those are usually orange, red, or blue plastic cups that are pushed in, but they can also be threaded plastic plugs. I have seen twice where people forgot to remove one of those cups. Some of them do not have the flat strip in the middle for grabbing it. Some have to be picked at with a pick or small screwdriver, then they can be pulled out with a needle nose pliers. It is possible to thread in the soft metal nut on the steel line with those cups still in there. It may sound stupid, but be sure those cups have been removed.
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Thursday, January 5th, 2017 AT 3:59 PM
Tiny
CARLUVR
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Yes, those seem to be the holes that we are referring to. The cups have been removed and no, it does not sound stupid to ask.
Now, we are wondering if the person that dropped by to try to help my dad may have crossed the high-pressure and return hoses up. I am being told they modified something so that the hoses would fit where they were putting them.
You have given us some things to try and we greatly appreciate that and your expertise! Hopefully we will not be contacting you again in a few days.
Thank you again!
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Thursday, January 5th, 2017 AT 5:21 PM
Tiny
CARLUVR
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Well, after doing some checking, my dad feels confident that the hoses aren't switched. He is planning on replacing the rack & pinion AND the pump and wants to know if you think that would fix the problem (given that all parts are as they should be)?
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Saturday, January 7th, 2017 AT 1:50 AM
Tiny
CARADIODOC
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I found that the hose ports are different sizes, so they can't be mixed up.

Did you drop the return hose into a bucket to see what you got for flow?

How did the original rack fail? Did it blow the same seal?

There is a pressure relief valve built into the outlet port of the power steering pump. I do not know how it does what it does, but it reduces pressure in the high-pressure hose to around 100 pounds when you are not turning the steering wheel, then as soon as you turn the wheel, pressure goes up to as much as 1100 pounds. That increase in pressure is related to increased flow. I've never run into a problem with that valve, so I don't know what the symptom would be.
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Sunday, January 8th, 2017 AT 4:12 PM
Tiny
CARLUVR
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Hello again! Sorry to have been so tardy returning this.A lot has been going on.
If I remember correctly, the original rack & pinion was shaking & leaking.
I do believe my father tested the hose. I will verify that.
He has purchased another rack & pinion, we have already noticed that the holes on this one are different sizes! (Great news, the others were the same) Now, we need to make sure that we don't mix this one up since this part really seems to be correct. Is there any way that you could verify which hole is the high pressure?
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Friday, January 13th, 2017 AT 2:59 PM
Tiny
CARADIODOC
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Yup. I looked this up last time. The two ports are different sizes. 16 mm and 18 mm, as I recall.
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Friday, January 13th, 2017 AT 3:06 PM

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