THE PORTAL HUB - Pinzgauers, Haflingers, Volvo 303s and more!

Greetings, I've recently changed all the oils in my 712 which has G-wagen power steering conversion using both the G pump and steering box. As I don't have any G -wagen info on oil specs I just used a dexron 3 ATF as used in most power steering setups. Now I have a slight groaning coming from the pump when its put under high load ... like going around a round about at reasonable speed, also it only really does this for the first 5 or so minutes of driving, so when fluid gets hot the noise seems to disappear. Should I have used some other Mercedes spec fluid? I can remember some time ago while servicing a merc 280 SE station wagon with the self levelling hydraulic rear suspension that a specific Mercedes hyd oil was specified for the pump used in this application, it was also recommended to me to not use a different oil as it would not perform well.
I have a feeling there might be someone lurking on the forum who will know the answer to this off the top of his head ... Gday Vince. Thanks in advance and great work with the forum.
Cheers Warren.

To answer my own question ...I just googled it and it seems I should have used Pentosin CHF11S or the genuine stuff Q1320001as dexron ATF probably isn't good for it if what I read is correct, in hindsight I should have known MB don't use dexron but this didn't occur to me at the time. Very few Km's driven I doubt there's any harm done.

swap it out and you should be fine
Once you drain it, add a bit and then drain that as well
Then top up with fresh

Depends on year. Don't forget the filter. A lot of people don't realize that those pumps (assuming you have the same G set-up) actually have a filter in them. It's really easy to check. It's at the bottom of the rod in your pump. https://mercedessource.com/problems/eng ... and-filter Look here.

https://mercedessource.com/store/power- ... luid-liter (for more related stuff)

Thanks Vince, I didn't realize that was a filter in the top of the pump.
Regards Warren.

Changed filter and flushed fluid now the groaning is gone. Thanks for the advice, particularly on the filter