audi 100 1990 power steering problem

[tonos]

I have a slight problem with my power steering. From a cold start the steering tends to kick in after a mile or two. Ive been told a couple of things such as the pump or the rack may be knackered. Ive also been told it may be an air lock in the system. Any ideas?

[adamss24]

Air lock will make it hard to steer anytime. Are there any leaks ? Its the level low and are you using the right fluid ? Also how its the colour ? It should be dark red, if its dark brown/black, i suggest replacing the fluid with the correct one !

[JohnnyBee]

Adam's dead right on this one, Tonos; the fluid gets a really hard time from day one on these motors, so what you probably have is a good substitute for molasses treacle underpinned by solidified tealeaves!
Best way round it is to get the system as warm as you can get it, then drain off everything you can by unplugging feed and return hoses, running them into a big bowl under the car.
Taking some of the weight off the wheels, work the steering back and forth to expel as much of the grunge as you can and when you've done that, try to clean as much black gunge out of the reservoir as well.
Next, re-attaching the hoses but loosely, refill the system with the pukka Audi fluid until you see fresh stuff coming out of the pump union, then tighten it up.
Now comes the messy bit; with the inlet hose to the rack just lightly nipped up, start the motor and gently work the steering left and right until all the bubbles stop coming out of the return union, then nip that one up too.
Tip: a big old sheet under the car would be a good insurance against domestic strife during the final phase of this procedure - you have been warned!
When turning the wheel from lock to lock no longer elicits growling from the pump, it means that all the air has been expelled from the system, but there's one more thing to do, and this is where it can get very messy.
Very carefully, slacken the unions on the outer ends of the rack and start the motor again, allowing the fluid to escape - rags over the unions will stop it spraying all over the place - and work the wheel to and fro until the drippings are clear enough to see through.
Finally, top the system up and tighten up all the unions on the system, taking care not to overdo the little ones as they are prone to stripping.
As an overview, the whole procedure is geared to getting rid of as much solid material from the system as possible without actually stripping it down and cleaning it by hand.
JB.

[tonos]

cheers for the information. I will get stuck into this and let you know how i got on.