Mixing power steering fluid?

My Volvo S60 has been making some strange noises when doing tight manouveres at slow speeds, not a mechanical noise but a kind of graunching sound.

I want to renew the PAS fluid as the first port of call and the fluid in the car is a dirty red colour (ATF). I have been advised by Volvo and by my local trusted Volvo speialist that it should have green (Pentosin etc) fluid.

I've bought 1L of green (ECP sold me the CarLube stuff) and a syringe to extract the old fluid, but obviously this plan isn't flawless as some ATF will remain in the pipes, so I will have to do it at least twice.

So basically my question is will mixing the red and green cause some kind of horrific chemical reaction that will melt all the seals and destroy the expensive rack (worst case scenario)!

As above, apart from it make no sodding difference about mixing oils as long as the viscosity grade/approvals are right.

It might be a better idea to undo a banjo bolt and drain the fluid that way, rather than trying to syringe it all out. I did this with my old CClass when the pump was dying.

And the sucky outy thingy is a Pela 6000

http://www.pelapumps.co.uk/default.aspx?a10page=pl...

I have one of those. Useful tool.

Is it as bad to put the green stuff in a system that wants ATF?

From a mixing point of view - I don't know.

However from a seals point of view, it is indeed a bad idea. The green stuff will eat the seals and you may well get a leak sooner or later.

(An aside, but ATF is dirt cheap, whereas the Pentosin stuff is expensive. I can understand using ATF in place of Pentosin but not vice-versa.)


Oli.

Fair enough - I'll keep my fingers crossed for you.

FWIW, I did something similar in my 944. Needed some new fluid and bought the green pentosin stuff by mistake (and thought at the time 'gosh, this is quite expensive!) Drained my system and put it in and it worked very well.

Fast forward about a month and - thankfully - the system started leaking. Thankfully? Yes, it had sprung a leak through the wall of a pipe, unrelated to the fluid choice. One new pipe and a bit of research later and I discovered that you shouldn't use pentosin in an ATF system as it eats the seals. I thus flushed the system with ATF and refilled it with the same stuff and all is well. I'm hoping that the pentosin wasn't in there long enough to cause any grief and think I learned an expensive lesson quite cheaply; a new PAS pipe from Pirtek was £40 whereas rebuilt racks come in at several hundred.


Oli.

I've had the car 4 years now and have never thought to have checked it before. It was leaking from the reservoir when I first bought it and a Volvo indy I don't use anymore now have another strike against their name as they were the last ones in there and would have topped it up in 2011.

So I will carry out a drain and flush, as has been said any damage will have already been done. Although there currently is nothing untoward about the feeling of the steering just the noise mentioned above.

Does it absolutely have to be the Pentosin/Volvo stuff or will any 'green hydraulic steering fluid' do the job?

Thanks for everyone's input so far.

That was exactly what happened to mine. I ordered a replacement reservoir and fitted it. From memory the hardest part was getting the hose clips off the hoses next to the reservoir. I reused the hoses after cleaning them and them seem fine.