• Welcome, Guest! We hope you enjoy the excellent technical knowledge, event information and discussions that the BMW MOA forum provides. Some forum content will be hidden from you if you remain logged out. If you want to view all content, please click the 'Log in' button above and enter your BMW MOA username and password.

    If you are not an MOA member, why not take the time to join the club, so you can enjoy posting on the forum, the BMW Owners News magazine, and all of the discounts and benefits the BMW MOA offers?

brake fluid in clutch

I understand how the driveline is setup I used to have an 1150R. I'd honestly rather see just a plain ol clutch cable setup instead of a hydraulic system of somesort. At least on these bikes it seems like it might actually be a step up in reliablity :whistle

Dont necessarily agree. If you use mineral oil I think the majority would find the hydraulic clutch actuation system is very reliable. More so than a cable. Also a lot easier to use. Clutch actuation issues on R's is pretty rare I believe.
regards
Paul
 
Maybe they didn't need to use brake fluid in this application but in the interest of making things simpler and more idiot proof, I wish they would have. Is mineral oil any better than brake fluid in this application? After I did this, I looked in my owners manual. It doesn't say anything about what fluid to use only to take it to a dealer if the fluid is low. On the cap it does say to only use mineral oil. It's my own fault for not making sure which fluid to use first.

The problem with brake fluid is that if it leaks at the slave cylinder, when it migrates along the clutch rod it doesn't just contaminate the clutch. It damages both the transmission input shaft seal and the engine output main seal. Then they both need to be replaced. Mineral oil is compatible with those seals so won't damage them. It also won't attract moisture and there really isn't any required change interval as there is for DOT 4.

All in all I consider it a big plus over the brake fluid.
 
<snip> there really isn't any required change interval as there is for DOT 4.

Correct. I asked my dealer if I could buy a pint of mineral oil to flush my clutch and they told me there was no regular recommendation to change it. They told me they could order me a quart if I really really really wanted. They did not keep any in stock except for what they kept for their shop.
 
Mineral Oil (hydrualic) to operate the Hydraulic operated Clutch is fine with me.

The benefit is its self adjusting and smoother.

David
 
+1 for what Paul said

While I've got a bit of sympathy for someone who has made the mistake of using the wrong fluid just how much more do you think the manufacturer should do- the reservoir cap is clearly written with what is supposed to go in it!!! Maybe contrasting colors and flashing lights?
READ THE LABEL - pretty simple...

There might be some people who just don't know there is a difference between hydraulic fluid and DOT4 brake fluid. In such cases one has to wonder whether they are really competent to be messing with a $20K piece of machinery and ought to just take the thing to a competent mechanic- the good ones are always worth way more than you pay them. Even though I'm able to do my own work, I sometimes pay one of my competent friends in the business to do it- keeps my contact lines open, saves a little time, always gives me the chance to learn a few tricks from the good guys who turn wrenches every day - hey, I'm only a part timer at it and like anything else in life, there is always someone who knows something I don't.
 
+1 for what Paul said

While I've got a bit of sympathy for someone who has made the mistake of using the wrong fluid just how much more do you think the manufacturer should do- the reservoir cap is clearly written with what is supposed to go in it!!! Maybe contrasting colors and flashing lights?
READ THE LABEL - pretty simple...

There might be some people who just don't know there is a difference between hydraulic fluid and DOT4 brake fluid. In such cases one has to wonder whether they are really competent to be messing with a $20K piece of machinery and ought to just take the thing to a competent mechanic- the good ones are always worth way more than you pay them. Even though I'm able to do my own work, I sometimes pay one of my competent friends in the business to do it- keeps my contact lines open, saves a little time, always gives me the chance to learn a few tricks from the good guys who turn wrenches every day - hey, I'm only a part timer at it and like anything else in life, there is always someone who knows something I don't.


I totally agree with you. I don't mind changing oil and simple tasks but these things are not like old airheads. I was at the National in MO last summer on my 2010 RT and a guy walked past me and pointed at my clutch reservoir with a disgusted look on his face and told me I needed to change the fluid before I ruined something. The bike only had about 5k miles on it at the time. When I got home and took it in to have the 6k service done I mentioned it to the expert mechanic who educated me.
 
Does anyone else want to rub salt in my wounds? I know it was my fault. After doing it I did see the warning on cap saying to use mineral oil. I had only owned one bike before with a hydraulic clutch and it used brake fluid. In hind sight it would have been cheaper to have a dealer do it. My only experience with the BMW dealer was after buying the bike a few months ago. It had been 1400 miles and 2 years since it's 6K service and service light was on. I paid $375 to change fluids and turn light off. that didn't include brake flush which they wanted another $110 for. I would gladly pay $80/hr for actual time spent working on bike but that's not how it works. I will continue to do routine maitenance but will be more careful in future. Even with a couple of mistakes, I still think I'll be ahead moneywise and learn a little in the process.
 
Hey, it happens. I decided to start cycling out the power steering fluid in my Mazda. So sucked out about an ounce and poured in an ounce of PS fluid, with plans to do this 32 times. After I did this twice, I discovered it uses ATF not PS fluid. Who would have thought! :banghead

Luckily, I only put in two ounces, and I continued my process with a quart of ATF. No problems with the car and only my own pride was damaged.:doh
 
I fix most anything myself. I'm WAY ahead on the money, and there's knowledge, independence, and satisfaction that goes with it. If I beat myself up over a little mistake once in a while I'd be quite unhappy. Write it off, move on, and be happy with the money you save in the longer term.
 
I fix most anything myself. I'm WAY ahead on the money, and there's knowledge, independence, and satisfaction that goes with it. If I beat myself up over a little mistake once in a while I'd be quite unhappy. Write it off, move on, and be happy with the money you save in the longer term.

Yea, yea, yea, just say it. I'm a cheap SOB too:D,


I need the $$$ to buy tires and gas.
 
Last edited:
jbarneshb, (real name? We're friendly around here..)

The year/model of your bike? Please read: http://forums.bmwmoa.org/showthread.php?46055. While as far as I know all hexheads used mineral oil in the clutch circuit, I've been known to be wrong on this sort of thing.. :) I'll edit the thread title once we know that info.

Thanks for your cooperation!
 
jbarbeshb,
Not trying to rub salt. As was noted, anyone who turns wrenches a bunch will sometimes make an error- we're all human and people make mistakes, hopefully with a low frequency influenced by learning. If one makes a careless error, especially if frequently, one needs to get out the game of wrenching unless that person likes paying others to correct the errors but the "once in a while from lack of knowledge" thing can happen at any time which is why building knowledge and contacts is key- greatly reduces chances.

For most of us, the screwup usually involves something simple like a bolt busted off the creates a complex repair situation that could have been avoided. You got bitten in a way that in the worst case could lead to a very expensive repair job so now you need to make some careful choices based on what you've read and what you're seeing so you don't land on "worse case". Most of us have been down that route, too

One excellent solution to necessarily high dealer prices (have to cover that overhead) is a qualified independent BMW mechanic near you. I've got a friend who was a long time dealership mechanic and owns many of the specialized tools needed for complex jobs- met him through the local BMW club. Very likely you might be able to find someone who is at least as close as your dealership and more cost effective especially if you use your local club members as an info source.

Many of us males have that bit of stubbornness where we can't let go of something we started. Sometimes its more useful to take a step back and ask what your time, sanity, and $ are all worth to you and try to make a Spock / rational choice about how to proceed. In my case, I can easily do any routine service as well as much complex stuff and it irks me a bit to let anyone else do it. But I've also got some health issues and sometimes some time issues- and I also hate letting my machines go way past their service intervals or to run them with damaged systems- I hate to buy new stuff or repair things that could have been spotted and easily corrected during a service and I don't belong to the school that accepts just handling breakdowns with plastic. As other pressures and issues in my life have increased, I have found it easier to let one of my competent pro friends do work for me- for the few $ it relieves all brain space the item would otherwise occupy- keeps me using my time and energy for riding rather than wrenching...
 
I pulled my slave cylinder off and could see no leakage. I reprimed it with a syringe and flushed it a couple of times with Magura Blood Mineral Hydrualc fluid. It operates the same as before. After a couple of hundred miles it hasn't lost any fluid. I'm just going to monitor the level in the reservoir and if nothing changes, I'm going to leave it.
 
If you've got all the wrong fluid out, flushed everything, and all appears normal the system ought to be good for use for at least a while and maybe as good as new. The wild card is whether any of the brake fluid has soaked into the sensitive rubber bits and slowly doing damage.
As a guess, its looks like you've going to get of without any serious issues.
Nice work......
 
Well I didn't get lucky. I noticed fluid level had gone down a little in clutch resovoir. I couldn't see anything at cylinder on handlebar so I pulled the slave cylinder. It was leaking. I bought and installed a used one off ebay. After using about 8 ounces of fluid to get it primed I figured out I should have filled the cyllinder first. I took the old one apart and could see the seal was eaten up. Just flushing or bleeding the system I probably didn't get any of the brake fluid out of the slave cylinder. I hope this is the last of my problems.
 
Back
Top