Changing power steering fluid

[Sean880]

As my VY is now 5 years old (but very low kms) I decided I should change the power steering fluid.

The only way to do this easily is to pump out old fluid progressively and replace it. This means drawing some fluid from the reservoir ensuring that the level stays safely above the top PS hose so no air gets into the system. Then top up with fresh fluid.

Run the car for a few days and do it again. Then repeat the process a 3rd and 4th time.
Sounds time consuming but it's not as it only takes a few minutes each time.

I found the old fluid I pumped out had discolored which is not surprising. Now that I have undertaken this process 4 times, a few days apart each time, the quality of the fluid in the system is looking new and clean even if there is a slight mix of old and new fluid in the system.

I propose doing it a couple more times in a few weeks.

To pump out old fluid I purchased a large plastic spray bottle with a trigger spray which is normally used for spraying water or cleaning products. The larger bottles have a larger feeder tube running to the trigger and thus can pump more fluid. (cost -$2.50 at a "reject shop")

You remove the trigger and plastic feed tube from the bottle and cut off the small plastic cylinder filter at the bottom of the feeder tube. (Some tubes have them - some don't).

Unscrew and remove the small plastic spray nozzle from the tip of the trigger mechanism.
(Don't use a trigger that does not have a removable spray nozzle).

Now you have a small trigger operated pump that is easily capable of pumping transmission fluid.

Clean the outside of the feeder tube.

To pump fluid out of the Power Steering reservoir, place the feeder tube (with trigger attached) into the PS reservoir. As the tube is small in diameter you can get it as low as you like. The lower the better. In your other hand have a container to run the old fluid into. Begin operating the trigger mechanism and it will easily begin pumping the PS fluid through the tube and trigger into your catch container.

DO NOT let the fluid drop to a low level in the PS reservoir. Ensure you keep it at a safe level above the top PS hose attached to the reservoir.

Now top up the reservoir with new fluid to the correct level which is marked on the side of the PS reservoir (cold fluid and hot fluid markings are there). Make sure you use the correct spec fluid (which is DEXRON 111 for the VY commodores - both V6 and V8 engine cars).

Keep everything clean so there is no contamination of the fluid.

Repeat the process a few times - days apart after driving the vehicle - until you have clean fluid in the system. Once set up it only takes a few minutes each time.

Perhaps not the best possible system but it works.

[Calaber]

Sean

You have gone to a lot of trouble to avoid getting air in the system, but I thought all you had to do was start up and operate the steering from left to right a few times to bleed any air out after replacing the pump, reserviour or fluid. It's no big deal getting air in the system as far as I know and it's easy to purge out.

[wortus]

I replaced mine that way except I used an old syringe with a piece of tube on the end. Fluid was black and after about 4 or 5 changes of the fluid in the resevoir it is now clean. It actually stopped the shudder at low speeds and after a year that is just starting again however fluid is clean. I also put in some Nulon conditioner but next time I wil use Nulon fluid instead of Dexron 3 to see how that goes stopping the shudder.

[Sean880]

Given that the Power Steering system has been designed to run on DEXRON 3, (and that's what GM specify), I would be very wary about using some other fluid.

[maginoodle]

Calaber, it is not the best idea to do it your way. I have done it that way many times and it does work. I have been told that the pump can cavitate and ruin the pump(has never happened to me).
What i have been told to do is have both wheels in the air and turn the steering from side to side while topping up the fluid to stop air getting in. Do this without the motor going.

The way i get the fluid out is to drain it from the rack, will cost you the price of a new O ring.

[VYIISSUTE]

Provided you can get someone to start and stop the engine and spin the wheel.

If your worried about the tyres just jack the car up.

I've found that you can lightly squeeze the return line with a brake line clamp, doing this means you can remove the hose on the other end (from the steel line) without losing fluid from the resivoir,
find a long peice of hose the right size to clamp over the steel pipe and stuff the other end in an empty drum, making sure the resivoir is full and you have about a 5 litre bottle of the right fluid get someone start the engine and spin the wheel from lock to lock, whilst this is taking place pour your fresh oil in (being carefull of course not to starve the pump), you'll have fresh oil in the system in a few seconds, refit the original line and remove the brakeline clamp and then it's time for a coldie!!

[wortus]

The Nulon fluid is suitable for Holden power steering and they reckon it can reduce shudder, given the shudder always comes back using Dexron 3, a specific power steerign fluid based on Dexron 3 with additives should be OK.

[Calaber]

I just re-read the original post in this thread and checked the workshop manual to clarify a point about those inlets into the reservoir.

As the top inlet into the reservoir is the return pipe, it should be quite safe to allow the fluid level to drain out below that pipe. After all, this is a reservoir we are dealing with, and the fluid in the reservoir is a reserve. If the entire contents of the reservoir was drained, less the bottom centimeter or so, then refilled with clean fluid, the pump will draw fluid from the reservoir as it requires it and pump it through the return pipe, which would enable the remaining old oil in the system to be replaced after only two or three cycles, instead of drawing only a small amount each time from the top of the reservoir and having to repeat the process six or more times.

Or am I missing something here?

[Calaber]

Well, I tried Sean's idea and found it worked very well. Easy to drain the old fluid out, though I drained the lot out on the first attempt. This means that there is only a small amount left in the pump, lines and rack, which will pump through within the first few seconds of use.

Drove the car and found no probs with air locks or noise - the old fluid was pretty dark and the shudder does seem to have diminished a bit. I reckon I can drain the reso. off again and will probably have removed 99% of the old oil by the time I finish it.

Well done, Sean. A simple, neat and effective method of addressing a potentially messy job.

[VYMAD]

Yeah thanks Sean, I've been using your method too and seems to work well for little effort.

[Sean880]

Thanks for the positive feedback. I certainly find it simple, fast and clean.

(Another topic - Replacing some brake fluid before bleeding your brakes.
By the way using a separate (smaller) trigger pump for drawing some old brake fluid from your brake fluid reservoir and replacing it with new fluid before you start the process of bleeding the brakes also works quite well and is not messy. Be extra careful not to splash the fluid or allow it to drip onto vehicle surfaces. It's always better to get some fresh brake fluid into the BF reservoir before starting the brake bleeding process but obviously don't let the level drop so low that any air can enter the system from the brake fluid reservoir. And wear rubber gloves.)
Cheers

[Calaber]

Another good idea, but just too late for this time round. Bled mine last week - the old fashioned way.

Good thinking mate.