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Fill to the bottom cold level mark and it shouldn't leak out.
Thanks! Just picked up a can, says it's good to 266 degrees F. I refilled it for now, and in a few days I'll flush it out with all new using a turkey baster, then repeat again a few days later.
That's weird, never hear that on these cars. The GTR guys like the Motul Multi ATF for higher temp stuff.
I hadn't either until I googled it today and found it's really common in the m156 and everyone's rectification was to zip-tie a rag around the cap. Hopefully this new fluid does the job filled to the minimum level.
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
Wanted to revive this thread as I'm planning to change out my fluid and want something robust for track duty just in case, even though I've never had an issue with whatever is in there now (Pentosin CHF 11S I assume).
First of all, ATF should NEVER be used on our ps system. Full stop. It will destroy seals. End of story.
Now, seems I'm left with 4 choices for hydraulic power steering fluids that meet or exceed MB 345.0:
- Pentosin CHF 11S (OEM fill)
- Motul Multi HF
- Redline Power Steering Fluid
- Amsoil Multi-Vehicle Synthetic Power Steering Fluid
They are all synthetic and conform to MB 345.0. Here are their technical spec sheets in the order as listed above. I'm not smart enough to interpret which one would be best for heavy track duty. Can someone translate these for me? The Redline and Amsoil fluids have significantly higher flash points than the Pentosin or Motul, but are also massively more viscous at 40C and a bit more at 100C. Some of the Porsche people complained about how thin the Pentosin is, and these other two appear to solve that issue, if it even is one. I just don't know what this all means, any help is appreciated.
The Redline and Amsoil fluids have significantly higher flash points than the Pentosin or Motul, but are also massively more viscous at 40C and a bit more at 100C.
That'd be hard on the pump. Are you willing to risk that for a dubious benefit, or even no tangible benefit at all?
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
Originally Posted by bhamg
That'd be hard on the pump. Are you willing to risk that for a dubious benefit, or even no tangible benefit at all?
I don't know, that's why I was asking. There have been some who say that during heavy extended track sessions, that the Pentosin thins out too much and destroys the pumps. Hence the more shear-resistant thicker viscosity options. They officially conform to MB 345.0, so should be fine, otherwise they wouldn't meet the spec at all.
I have the Redline on the way as it was readily available on Amazon (with a bottle of Pentosin just in case). We will see.
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
Flushed out the power steering fluid tonight. I ended up using the Redline for its higher temp properties, and it's also more viscous at higher sustained temps that I see on track which should provide some added protection.
And it looks like I'll need it. First drain out of the reservoir, whatever was in there came out BLACK. I drained into an empty bottle, and light wouldn't even pass through it. No bueno. Fill with Redline, start up car, turn the wheel back and forth for a minute, shut off car and drain again. Still coming out black. Again. And again. And again. Last time it came out a bit murky, but was massively better than what was in there. Used up the entire liter of the Redline doing it, probably should have used the Pentosin for the flush, but whatever. This should last me awhile, but the PS fluid was clearly never changed.
I can tell that the steering feels much lighter and smoother already, and no noises from the rack that I had before but didn't really notice. Hope there's no real long-term damage....
Flushed out the power steering fluid tonight. I ended up using the Redline for its higher temp properties, and it's also more viscous at higher sustained temps that I see on track which should provide some added protection.
And it looks like I'll need it. First drain out of the reservoir, whatever was in there came out BLACK. I drained into an empty bottle, and light wouldn't even pass through it. No bueno. Fill with Redline, start up car, turn the wheel back and forth for a minute, shut off car and drain again. Still coming out black. Again. And again. And again. Last time it came out a bit murky, but was massively better than what was in there. Used up the entire liter of the Redline doing it, probably should have used the Pentosin for the flush, but whatever. This should last me awhile, but the PS fluid was clearly never changed.
I can tell that the steering feels much lighter and smoother already, and no noises from the rack that I had before but didn't really notice. Hope there's no real long-term damage....
Will report back on road and track performance.
Let me know your results. I flushed mine about 3 times (drove the car between each flush for awhile) with Pentosin to get it clean. I am still running pentosin but filled to the lower cold mark. I have no idea how full it was when it boiled over at the track, hadn't even though about needing a better PS fluid for track duty honestly.
I haven't had it back to the track yet with it filled to the lower cold mark, there's a couple events in August I have my eye on however.
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
How dark was your old fluid when you flushed it? I'm going to drive it like this for a week or two, and do it all over again to make sure the fluid is as clean as possible and all the old fluid from inside the rack is out. Pretty disappointed it was so bad.
How dark was your old fluid when you flushed it? I'm going to drive it like this for a week or two, and do it all over again to make sure the fluid is as clean as possible and all the old fluid from inside the rack is out. Pretty disappointed it was so bad.
Did you change out the power steering reservoir when you changed the power steering fluid? I just had my power steering serviced at my Indy and the reservoir was swapped out as well since there's a filter inside of it....maybe that's why the fluid kept coming out black?
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
Originally Posted by tfthach13
Did you change out the power steering reservoir when you changed the power steering fluid? I just had my power steering serviced at my Indy and the reservoir was swapped out as well since there's a filter inside of it....maybe that's why the fluid kept coming out black?
Just a an idea.
I heard about that filter, but did not change out the reservoir. Will do that this winter, thanks for the reminder.
Isn't it just a large debris screen filter? May not be worth the effort.
Exactly right, it's mesh screen type filter due to the high volume of fluid that moves through the system. Black sludge will definitely form on that type of filter though, I've seen it on other cars before.
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
Can't use the Amsoil ATF. Need their Multi-Vehicle Synthetic Power Steering Fluid (PSF) from the pic above. Totally different things, I think I posted a link somewhere on what ATF will do to a hydraulic PS system.
Glad I researched before dumping in Motul Multi ATF like I was originally thinking of doing.
06-24-2017, 05:44 PM
