Is the clutch fluid is mineral oil ??

I suppose it would be helpful if someone would read the owners manual and report back here. Better yet! Talk with a technician at a dealership who is willing to be candid. Virtually all other modern motorcycle & automotive hydraulic brake AND clutch operation systems use DOT 3 or DOT 4 brake fluid. BUT it seems that BMW wants to be your only source of "mineral oil" to use in your bike. I did a search and got plenty of web sites that talk about Vitamol V10, Blue V10, Blue Magura Fluid, Magura Blood and "mineral oil". The term "mineral oil" is often used when referring to "mineral based" motor oil, which just means engine oil which is NOT synthetic. That's definetly not something to be used in a hydraulic system. There is also the "old" term of mineral oil, which can still be bought in a pharmacy and is clear oil, derived from petroleum and used as a generic household lubricant like the old "3 in 1 Household Oil". One website that I found had a post saying that Vitamol V10 is a 10 wt hydraulic oil. That seems logical. And conventional hydraulic oil is what's used in tractors, fork lifts, etc. to operate the hydraulic cylinders that move plows, lift heavy objects, steer the machine, etc. Such hydraulic oils are NOT the same as, and should not be mixed with DOT 3 or 4.
What's it all about Alfie?
I dunno and the R18 will be my first BMW with anything that's hydraulically operated. My '65 R50/2 only had cables to operate anything mechanical.
Personally, I am going to look into this. But the obvious thing to do for those of us who are not BMW experts is to stick with what the OEM says to use in the owners manual.
 
This a very confusing thread, as previously mentioned the R18 single-plate dry clutch, no fluid. The op mentioned the clutch side reservoir which the MOM does not reference. The MOM does reference both front and rear brake use DOT4.
 
R2K said:
This a very confusing thread, as previously mentioned the R18 single-plate dry clutch, no fluid. The op mentioned the clutch side reservoir which the MOM does not reference. The MOM does reference both front and rear brake use DOT4.
Click to expand...
The R18 has a DRY clutch, which means that the clutch itself is much like most automotive clutches, i.e. the clutch is not wet & lubed with the oil that the transmission is bathed in. So it's called a dry clutch. Many clutches in Europen bikes (and most cars wherever they are made) have dry clutches. Most asian brands of motorcycles and modern Triumphs have "wet clutches" which are enclosed in the same part of the engine cases as the tramsmission, so they are "wet" with the same oil. With many motorcycles the clutch is OPERATED by a hydraulic system that uses a specific oil from the master cylinder [at the LH handlebar] to the slave cylinder [exterior to the engine case]. The typical tell-tale of a hydraulically operated clutch is the master cylinder and it's adjoining resevoir at the LH grip. At the far end of the system there will be a "slave cylinder" exterior of the engine case.
 
Reason is I want to upgrade the clutch master cylinder later to Brembo, RSD, etc.
Last time I did on my R ninet we have difficulty because All after market they use DOT4 fluid on Master cylinder clutch, but BMW using mineral oil. The oring inside Aftermarket's MC cylinder DOT4 is not happy with BMW Mineral oil.

So it seem BMW still using Mineral oil for their clutch cylinder. Very hard to find upgrade.
 

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firstime911 said:
Reason is I want to upgrade the clutch master cylinder later to Brembo, RSD, etc.
Last time I did on my R ninet we have difficulty because All after market they use DOT4 fluid on Master cylinder clutch, but BMW using mineral oil. The oring inside Aftermarket's MC cylinder DOT4 is not happy with BMW Mineral oil.

So it seem BMW still using Mineral oil for their clutch cylinder. Very hard to find upgrade.
Click to expand...
That is exactly why the question of what fluid to use is so important. In your case, you would like to upgrade the master cylinder, but the same issue with regard to the hydraulic fluid comes into play if a rider simply needs to top off or bleed-out the system.
There are many types of rubber used in o-rings and "cups" as part of brake and clutch hydraulic systems. A rubber compound that works well with conventional hydraulic oil may degrade if it comes in contact with DOT 4 brake fluid and vice versa.
 
I’m in the process of installing the beach bars. The instructions specify DOT 4 for the brake cylinder and Hyspin V10 fluid for the clutch cylinder.
 
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