Correct power steering fluid

Dave999 · Post by **Dave999** » Mon Aug 07, 17 12:01 pm

yeah that was in the days when ATF was probably a mineral oil based thing. a basic liquid that didn't compress, had some nice anti forming additive and a corrosion inhibitor and caused rubber seals to gently swell a prescribed amount to seal the box and pump for many years

these days its not necessarily so its a modern concoction designed for modern pumps and racks all of which will use a synthetic neoprene style plastic seal that seals based purely on dimension.

the modern stuff is supposed to damage the seals, is too "wet" i.e it escapes through smaller gaps and is supposed to eat yellow metal parts.

no idea if its all true but.....

just like engine oil the additives have followed the technology

i.e not best suited to old tech but fine for a modern power assisted set up

depends what your pump and steering box uses for thrust washers and seals.

I have a 4speed manual designed for SAE30 engine oil

you can run ATF in them and many did for years but modern stuff is supposed to have an adverse effect on the syncro rings which are a yellow metal. (brass/bronze erm...whatever combo it is)

the box is an early relative on the BW T5
modern T5s have plastic fibre with paper lining syncro rings they work great with dextron 3

but you wouldn't run it in a 80s t5 that has the metal syncros
and I don't think id put it in my 60s based 4 speed

i'm sure there are plenty who do with no detriment but someone somewhere must have had an issue.

Dave

MilesnMiles · Post by **MilesnMiles** » Mon Aug 07, 17 10:19 pm

Dave, I bought the stuff you listed a while back.
All good.
At the moment

David Murray · Post by **David Murray** » Wed Aug 09, 17 4:33 pm

My understanding is that actual PS fluid has something in it which acts to condition/soften rubber seals. Indeed, if you accidentally pour it into your master cylinder instead of brake fluid it will swell the seals to the point that the brakes stop working....hmm...did I really do that?!? But when used, as intended, in a PS system, that same effect works to stop leaks from hard, shrunk rubbers.

I've had two Mopars now where the PS reservoirs were full with Dexron and both leaked, but when drained and refilled with the correct Mopar stuff, the leaks gradually stopped. Might be coincidence, but for a few quid extra and having to order online, I'd choose the original Mopar PS fluid (careful with part numbers) any day...or the Red Line equivalent. I'd wager that any mineral PS fluid would do the trick....but I buy the Mopar stuff so no proof of that.

MilesnMiles · Post by **MilesnMiles** » Wed Aug 09, 17 6:20 pm

David, pretty much what I thought. I've mixed some Lucas stop leak with some mineral based PS fluid and so good, so far.

freighdog · Post by **freighdog** » Mon Aug 21, 17 8:01 pm

Ok, so I've committed a heinous crime and put some German made fluid from GSF in!

But on the plus side, it's cured two weird noises I had coming from the front end!

Dave999 · Post by **Dave999** » Fri Aug 25, 17 4:46 pm

no I think GSF supply both types

either way your steering will work

if seals start to ooze swap to the stuff for old cars and see if it gets better

I'm under the impression that its probably not the end of the world either way

freighdog · Post by **freighdog** » Fri Aug 25, 17 9:32 pm

I did ask them for the mineral oil stuff, as suggested. I'll keep an eye out for leaks.