Hydraulic fluid question - PeachParts Mercedes-Benz Forum

Emmerich · #1 12-25-2010, 07:08 PM

I have a BMW 840, turns out the power steering uses hydraulic fluid. The cap says CHF-11.s or something close to that. I have some leftover hydraulic fluid from my 6.9, but the label is gone, anybody know if the 6.9 fluid can be used in the BMW?

thanks
Fred Emmerich

layback40 · #2 12-25-2010, 08:51 PM

All you ever wanted to know about Mercedes fluids but were too afraid to ask !!!!

http://bevo.mercedes-benz.com/bevolistenmain.php?session_id=&navigation_path=bevolisten&language_id=1

If you can find your fluid there & have the required spec for the volvo, you can cross match.

PaulC · #3 12-25-2010, 09:37 PM

If the fluid winds up being chemically incompatible to the soft parts of the system...

strelnik · #4 12-25-2010, 09:59 PM

Quote:

Originally Posted by Emmerich

I have a BMW 840, turns out the power steering uses hydraulic fluid. The cap says CHF-11.s or something close to that. I have some leftover hydraulic fluid from my 6.9, but the label is gone, anybody know if the 6.9 fluid can be used in the BMW?

thanks
Fred Emmerich

Fred,
The biggest, most serious issue about hydraulic fluids no longer exists.

In the 1960s, when the M100 was made, the era was ending for custom hydraulic systems which used vegetable-based hydraulic fluid, versus mineral-based hydraulic fluid. The early (1955-1965) Pentosin-brand fluid, aka CHF-2, was vegetable-based hydraulic fluid similar to brake fluid. IT COULD NOT BE MIXED WITH MINERAL-BASED FLUID. The rubber parts on these systems were made from a product called EPDM, which would dissolve on contact with the later fluid.

Early Citroens, Bentleys and Rolls-Royce cars used the vegetable-based fluid initially, to about 1968, tho French and German cars got rid of it in 1965.

The M-100 cars used the later mineral based-fluid, the most popular being LHM and LHM+ , both of which are still usable now. All rubber parts on these vehicles are made from a material similar to Buta-N, which is compatible ONLY with mineral-based fluid, including Dexron 3 in a pinch.

CHF-11,made by Pentosin, is a more modern, evolved form of the original stuff. A good general fluid which cannot hurt anything is Hyken Glacial Blue, used in many high-pressure auto and construction hydraulic systems. The main differences between these systems now are additives for rust resistance, reaction to the metal components in the hydraulic system, anti-hydroscopy (prevents absorption of water) and dirt emulsification to keep dirt from blocking tiny holes in automatic leveling valves.

Could you use the stuff? Yes, in a pinch, but how long has it been sitting on the shelf?

I would, at the very least, pour a little out and see. Plus, check out the fluids and see what the difference is between the fluids according to the tech websites.

Skippy · #5 12-27-2010, 10:08 AM

Interesting. I see I'm not the only one suffering from fluid confusion. We did some service the other day on a John Deere 200CLC excavator. The thing was way low on hydraulic fluid and we didn't know what it took. The MRC (Maintenance Requirement Card-don't ask) had some weird specification for fluid that I couldn't make heads or tails of. The manufacturer's manual wasn't any better. What we had on hand were 80W90, 10W, 30W, 15W40, and 40W. We all ruled out 80-90 pretty fast, but were stumped after that. I was thinking 10W, but I had to leave the shop for some or another reason, and by the time I got by, one of my guys was filling the tank with 15W40. So far, so good.