Pwr Steering Fluid w/ Stop Leak
 

I have a slight leak in my Power Steering pump on my 92 400SE. The shop wants about $500 to remove the PS pump and replace the seals. Has anyone tried any of the "stop leak" additives?

Since the leak is very light and PW fluid is only about $10 a qt, for $500 I could have the leak MANY years before my $500 investment would return a payback.

Any thoughts?

Russell

But what a mess it would leave under your car and everywhere you park! Your friends would banish your car from their driveway!

Is it really that difficult to repair?... are special tools needed? FastLane lists the pump repair kit for under $40. I'm not a big fan of any fix-in-a-can, but then again I do all my own work, so labor isn't an issue.

It's a very slight leak. Gosh, I probably wouldn't go through qt of PW fluid in a month. There is not a issue with leaking on the payment, due to the "cover plate" under the engine attached to the frame.

I have used PS stop leak with good success in the past.. Looks like to me you have almost nothing to loose.. The stop leak only cost about $3.00.. PS fluid should not cost $10.00 a quart.. Autozone has Synthetic for abou $5.00 a quart..

Just remember.. It takes a little time for the seal to expand.. In the old days, we used to just pour some brake fluid in to swell the seals.. It's probably the same thing..

Have you been using ATF in the Power Steering system? Just curious.

You need to wash the pump really well at the coin carwash and watch closely to ensure that it is indeed the pump leaking, then get a wrecking yard pump for about $125.

Use regular power steering fluid from the auto supply. It costs less than $3 per quart and works great. That's what I've used in my 240D p/s system for the last 400,000 miles with absolutely no ill effect.

Good luck,

I've been using only Mercedes PS fluid I purchase from the Dealer.

good ol' Pyroil PS fluid from Kragen and Pep Boys has the same smell and color as the stuff from the dealer. They're both made by Valvoline. :)

stop leak
 

I have had good results with Lucas power steering stop leak..

its about 7 bux a pint but it should do the trick after a few hundred miles...

used it in my 1990 300 D and after about a week or so the leak stopped .. this was a few months ago ,,

first i tried bars leak and it didnt work... drained everything out
and filled with 100% lucas stop leak .. seals have sweeled and no more leak!

well worth the 16 bux it cost me!!:p

I'm not sure of the suspension configuration on the 400SE, but on my 420SEL, the power steering fluid that would leak out, liked to drip over one of the subframe mounts. The rubber in the mount did not like this at all, and protested by swelling and making itself near useless. Unfortunately, the rubbers weren't replaceable, I had to get a whole new armature (not cheap).
So, not only did I pay to have the leak fixed, but also to have the subframe replaced, because I waited too long.

In essence: Check to make sure the fluid isn't leaking on expensive to replace parts.

-Larry

how come the owners manual on all three of my MB's , 'yes I have the manual for my 74 240 D" say to use ATF?.......
William Rogers......

nthach (I know you must be a Vietnamese :-): Valvoline makes Pyroil P/S fluid while dealers sell Febi P/S fluid. Different companies. Only the antifreeze coolant stuff from dealers is the same as Valvoline's Zerex G-05.



william rogers: the mentioned ATF is ATF type A, which is a very obsolete ATF that you may never be able to find in retail stores. New ATF fluids such as Type F or Dexron III/Mercon have all kinds of extra additives that may deteriorate the P/S seals and cause leaks.

So, the best and safest stuff to use for your P/S system is the cheap regular P/S fluid (Pyroil, Gunk, Coast, SynPower etc...) you can always find in auto parts stores.

Eric

William,

The owners manual says to use ATF because it was written years and years ago. At that time ATF was a satisfactory hydraulic fluid with no ill effects. Since that time ATF has gone through drastic evolution. The ATF of today has additives that are BAD for the seals in your power steering system.

When your owners manual was printed, most all cars used ATF in the p/s systems so you didn't even see a different fluid on the shelf for power steering. It was not necessary.

Once the mfg's saw that ATF would wreck the p/s system then the "Power Steering Fluid" products started showing up on the shelves at the dealers as well as the parts stores. Unfortunately, they had no way of going back, pulling the owners manual from your glove compartment and rewriting it.

Hope this explains it,

Thanks for that info Larry.

My E30 BMW has a rack leak (like most of them) I used a really cheap stop leak and it worked well for about 8,000miles before a leak showed up again. I then used a more expensive additive that did nothing at all.

However, if I had been using power steering fluid instead of ATF, perhaps I would have had better results.

I read in a early 80's car care book(quite useful too), and GM was calling for a special fluid(Delco something) for power steering.

Thank Larry, that tip is worth its weight in sunroof lube,do you have any recommendations as witch brand fluid to use or are they all similar.Any tips for draining
the systems........
William Rogers....
74 240 D
81 SD
86 Euro 500 SE
81 hot rod Blazer.......

i use Pyroil myself, same thing as dealer fluid that comes in the blue motor oil bottle,

I've heard of others using Mobil 1 10w-30 for years with no ill effects, and others still like Mobil 1 syn ATF which says its Okay for Vickers vane pumps. Its my opinion that some pumps will leak and some won't just like some trans last a long time and some don't. Sometimes poorly serviced trans fail long before well serviced trans. Febi P/S fluid is slightly difference from the dealer formulation: they look and smell different.

The dealer stuff is now made by Valvoline, they don't import it from Germany anymore.

William,

I use whatever brand Power Steering fluid that I find at the auto parts house. It's not like engine oil where you have to worry about additives or weights clashing from one brand to the next.

The method I use for flushing/changing the p/s fluid is actually a question on the ASE test. Remove the return line from the reservoir and lower it into a drain pan. Remove the reservoir cover. Stand above the reservoir at the ready with two quarts of p/s fluid. Have an assistant start the engine and start turning the steering wheel back and forth, lock to lock. After the reservoir empties, start pouring in p/s fluid until the two quarts are gone and flushed through the system, then tell the assistant to shut it off.

Reconnect the return line and fill the reservoir. Have assistant restart engine and start turning lock to lock to bleed system as you carefully top off the reservoir.

md21722,

Engine oil of ANY kind is a BAD choice for your p/s system. It has detergents that will create foam. The main characteristic of p/s fluid vs. engine oil is that it does not tend to foam.

Have a great day,

Steering box leak
 

While in for MB service, I was informed my steering box was leaking slightly, $300 or so to R/R and reseal. I usually dont believe in additives but I removed some fluid and added "LUCAS" steering something. I have not seen the level go down, and at the last oil change no mention was made.
I asked a personal friend and owner of a "Foreign Repair" garage and got a "ya,ya, wait untill the seals deteriate". Its over a year, now it might not work for everyone, but if and when it leaks again I will worry about it.

I've been told by a few people that P/S stop leak is the only additive that does somthing possitise, as it resoften seals and stops leaks. Some people even put it in new cars so they never had to deal with a leak.

Wish I had known earlier though. $440AUD latter... :(

$500 is a lot to replace PS seals.

I have used various stop-leak products and, quite frankly, they do not work. Some actually make the pump leak even faster, draining the reservoir in a day. Also, the PS pump seals are so insubstantial in size that I don't see how the stop-leak additives can work on them. There simply is not that much to swell.

If you are leaking from the front seal, you will eventually have belt squeal and oily engine bay issues -- which is the point of no return where you have to reseal the pump. If you are a do it yourselfer, here's a link to how I resealed mine, with photos:

http://www.peachparts.com/shopforum/showthread.php?threadid=63549&highlight=Power+Steering

The most labor intensive part is removing the pump from the car -- unless you know exactly where all the mounting bolts are. then it is pretty fast. Depending on which pump you have, replacing the seals takes only a few minutes.