clutch fluid

The slave cylinder is mounted on the transmission, and is subject to engine /transmission oil. The type of seals used in brake systems (DOT 3,4,5) are not oil resistant. So since they they have to be oil resistant, they use mineral oil in the clutch hydraulic system IMHO.

Joe

2nd,

I wanted to include in here another little bit of information. I just bleed the clutch on my bike recently and instead of ordering the 2.5oz bottle of mineral oil form Magura for $5 and waiting a week to get it, I use a $0.97 bottle of baby oil from Walgreens and got enough mineral oil to flush the system and fill it 10x. Baby oil is just that, mineral oil, but with a fragrance added.... my clutch smells baby fresh!!! I have been riding the bike for about 3 months now with the baby oil in and have not had any problems what-so-ever. In fact, after flushing the system and refilling it, The clutch never felt so good before. Just wanted to share this little bit of info.....

Regards,

Yep, never use any type of brake fluid in a Magura clutch. ATF and suspension fluid (5 wt.) are two tried and tested alternatives that are less costly and easier to find than the overpriced Magura stuff.

Mineral oil (baby oil without the fragrance) can be bought in the pharmacy at any Walgreens. I used that last time and it works good but it is heavier viscosity. Doesn't seem to bother unless it is cold and then the clutch is rather stiff. Switched it to cartridge fork oil and all was well. Didn't know how the seals would last long term so I eventially changed it back to the Magura. From what all the guys say, I could have left the fork oil in.
dan

Having to bleed the clutch on my 00, I used baby oil for about a year. I noticed it was a little stiff in the winter and changed it to ATF. My 04 has ATF in it also. Thats 5 years on the 00 and 1 year on the 04 on ATF with no problems.

Regards,

Joe

Hello again. As to what Joe and Dan posted regarding the baby oil or mineral oil feeling a little stiff in the winter I have not experienced this problem But I live in the SW desert of Arizona where temperatures rarely drop below 50 degrees. This may account for me not noticing that there is any stiffness in the clutch, in fact im sure of it as I don't get out and ride much in the cold weather, but this good to know for those of you who do ride in colder climates. It is also good to know that ATF is being used with favorable results. Thanks for the info fellas! Take care.

Regards,

I have had ATF in my 01 since about June of 01 and never had any problems, I have about 130 hours on that bike. I switched to ATF b/c I had read somewhere a long time ago that was acceptable, and ATF is readily available. I still have the stock fluid in my 04 and it is working just fine.

As to which type, I use Mercon ATF.

For what it may be worth and based on personal experience:

You can indeed use brake fluid in many Magura products.

Example:
I use an OEM Husaberg Magura clutch master cylinder to hand operate the rear brake of a CRF dirttracker sporting an automatic clutch. Said hand lever works in conjunction with the OEM Nissin rear master cylinder and caliper. Said application has been in service for over a year.

Using oil in a DOT brake fluid specified cylinder will likely lead to disaster. However, to date using DOT 3, 4 or 5 Brake fluid has yet to cause any problems in THE Magura products I have tested.

Regarding non brake applications:
I have successfully used baby oil and Magura "Blood".

DOT specification brake systems most often do not take kindly to petroleum products of any nature. Such is why I tested the Magura compatibility with brake fluid when I opted to use their clutch cylinder for a brake application as opposed to running mineral oil in the system.

OK, So I know it is coming :roll:
"If DOT brake fluid is so good why doesn't the OEM use it." My best guess is because brake fluid is truly nasty stuff when compared to that of mineral oil.

Last however not least, DOT 4 is superior to that of DOT 5 (ie less compressibility and easier bleeding) with exception of DOT 4 being an efficient paint remover and hygroscopic. :?

Kind Regards,
Dale

LINEAWEAVER said:

For what it may be worth and based on personal experience:

You can indeed use brake fluid in many Magura products.

Example:
I use an OEM Husaberg Magura clutch master cylinder to hand operate the rear brake of a CRF dirttracker sporting an automatic clutch. Said hand lever works in conjunction with the OEM Nissin rear master cylinder and caliper. Said application has been in service for over a year.

Using oil in a DOT brake fluid specified cylinder will likely lead to disaster. However, to date using DOT 3, 4 or 5 Brake fluid has yet to cause any problems in Magura products that I have tested.

Regarding non brake applications:
I have successfully used baby oil and Magura "Blood".

DOT specification brake systems most often do not take kindly to petroleum products of any nature. Such is why I tested Magura compatibility with brake fluid when I opted to use their clutch cylinder for a brake application.

OK, So I know it is coming :roll:
"If DOT fluid is so good why don't the OEM use it." My best guess is because brake fluid is truly nasty stuff when compared to that of mineral oil.

Last however not least, DOT 4 is superior to that of DOT 5 with exception of DOT 4 being an efficient paint remover.

Kind Regards,
Dale

Click to expand...

That's interesting that you have tested brake fluid and it worked. Although it is just a small amount of brake fluid, what about when the slave cylinder leaks brake fluid (into the engine)? Maybe that's why oil is specified?

That's interesting that you have tested brake fluid and it worked. Although it is just a small amount of brake fluid, "what about when the slave cylinder leaks brake fluid (into the engine)?" Maybe that's why oil is specified?

Click to expand...

Told you it was coming: :lol:
"If DOT brake fluid is so good why doesn't the OEM use it."

Hi John,

Brake fluid is more akin to antifreeze then that of oil. Should brake fluid find its way into the engine I would expect similar results to that of mixing antifreeze and engine oil. :?

Brake fluid is simply nasty stuff. If a satisfactory alternative exists, why not use it :?:

Magura is big into mountain bike hardware. Said components always call for "Magura Blood" (ie mineral oil).


Best Regards,
Dale

Never gets too cold here in Yuma, yet clutch was stiff in the winter. Wonder if they make different weights of mineral oil which one should match to the degree of constipation you are suffering?
dan

I have had two customers use DOT4 fluid in there ktm clutch cyclinders one for about a month then had problems and we found that the cups had expanded that much that we could not bleed it we replaced the parts and used fork oil and every things ok

the next guy used it for the weekend and saw me on monday i recomened to change the oil as soon as he got home and he did ,his clutch is ok and that was about 6 months ago

nzberg said:

I have had two customers use DOT4 fluid in there ktm clutch cyclinders one for about a month then had problems and we found that the cups had expanded that much that we could not bleed it we replaced the parts and used fork oil and every things ok

the next guy used it for the weekend and saw me on monday i recomened to change the oil as soon as he got home and he did ,his clutch is ok and that was about 6 months ago

Click to expand...

Hi nzberg.
Dot 4 will indeed most often cause a bit of seal swell even on systems designed for such. Unfortunately, petroleum oil will most always destroy a brake fluid specific seal and mineral oil does not provide for a good brake fluid. Such is the case which prompted my personal decision to "test" brake fluid in Magura components.

Note:
For clarification I do not recommend one replace their clutch fluid with that of anything other than mineral oil.

Sincerely,
Dale