DOT 4 cross contamination with Mineral oil Clutch Fluid . . Who Wins??

[Kiwi Rider]

This one's a doozey, I need the oRg's help and vast knowledge with this . . .

As many of you know, I ride with a couple of guys regularly and one has bought a K1300S BMW recently.
The previous owner had fitted an aftermarket handlebar set to it, but Mike hated the higher bars and wanted to fit the standard bars back to it. He was given all the standard parts necessary to revert back to stock.
So it begins . . he knows little mechanically ( he's a house painter) and has feck all tools and was hesitant to ask me to do the job as I'm snowed under between working all day on bikes and getting home to work all evening on cash jobs on bikes.
So he asked our other riding partner who is mechanically literate and maintains his own bikes to a high standard.
So far so good, but here's where it goes pear shaped . . .
The brake and clutch reservoirs had to be removed and hoses disconnected from the master cylinders.
The brake system uses DOT4 Brake Fluid but the clutch system uses mineral oil clutch fluid as is common in some European bikes (KTM uses this also in their clutches)

Anyway, my mate didn't see the warning on the reservoir cap to use only mineral oil and started bleeding it up with DOT4.
He rang me for advice on why he was having trouble getting any hydraulic pressure at the lever and it was at that point I asked him if he's used the correct mineral oil in that system.
A deafening silence fell over the phone line.
I told him to clean out all the DOT4 brake fluid with compressed air thru the hose etc, and refill with correct oil.
Well, he flushed it out thoroughly and added mineral oil and flushed 300mls of that thru and it appears to be working normally.
My question to the oRgsters is . . . does anyone know for sure exactly what will be the long term effects of putting DOT4 through the M/Cyls seals ?
Will it damage the seals by causing them to expand?
I've heard conflicting info on this issue, but I'm really wanting accurate info.
Anyone?

[rubbersidedown]

I could bore you to tears my brother with what I know about the 2. Unfortunately I could not give you a 100% guaranteed right answer.
You are correct thou...they are not compatible under ANY circumstances.
Others may chime in,you can read about it etc. I have a friend who actually really has fun attending things like 3-day seminars on motor oil.
He is prolly asleep at this time. I will ask him tomorrow. He may know.
What I would do if someone did that to my bike...throw it all out. I am that a n a l. What should/could you suggest they do. Total re-build of all componants.BUT... The bit of time those parts were exposed to the wrong fluid has prolly done little or even no damage. Those componants are pretty tuff and not very susceptible to degradation. Look at it this way...Dot 4 is OK for use in these types of systems...so is mineral...same componants...just filled with a different fluid from the factory.
Perhaps dismantle,clean everything 100%,throw it back together,call it good.
Tuff decission. Maybe just stop taking his calls.
Rubb.

[Mythos]

Hope you get an ex-spirt.

I'd say it's fine as long as the brake fluid was replaced with the proper oil very promptly. DOT 5 is the one you have to avoid if it's a system designed for DOT 3 or 4. I have been told DOT 3 and 4 are the same fluid. AS for a system designed for mineral oil, I'd imagine it was diluted sufficiently with mineral oil if the clutch is working again.

[Kiwi Rider]

I could bore you to tears my brother with what I know about the 2. Unfortunately I could not give you a 100% guaranteed right answer.
You are correct thou...they are not compatible under ANY circumstances.
Others may chime in,you can read about it etc. I have a friend who actually really has fun attending things like 3-day seminars on motor oil.
He is prolly asleep at this time. I will ask him tomorrow. He may know.
What I would do if someone did that to my bike...throw it all out. I am that a n a l. What should/could you suggest they do. Total re-build of all componants.BUT... The bit of time those parts were exposed to the wrong fluid has prolly done little or even no damage. Those componants are pretty tuff and not very susceptible to degradation. Look at it this way...Dot 4 is OK for use in these types of systems...so is mineral...same componants...just filled with a different fluid from the factory.
Perhaps dismantle,clean everything 100%,throw it back together,call it good.
Tuff decission. Maybe just stop taking his calls.
Rubb.

Great reply Rubbster....
I’m totally with you, especially the bit about “just stop taking his calls” .... nearly sat my coffee out when I read that

[Kiwi Rider]

Hope you get an ex-spirt.

I'd say it's fine as long as the brake fluid was replaced with the proper oil very promptly. DOT 5 is the one you have to avoid if it's a system designed for DOT 3 or 4. I have been told DOT 3 and 4 are the same fluid. AS for a system designed for mineral oil, I'd imagine it was diluted sufficiently with mineral oil if the clutch is working again.

Yes, DOT 5 is a silicone fluid, contamination to be avoided at all costs, the clutch appears to working fine.
Just going on a 200km ride with him on that Beemer so will let you guys know how it all pans out with the operation of the clutch on his bike.
Thanks for your time peeps!

[Kiwi Rider]

OK, so I went for a 200km blast today with the Beemer guy, Mike.
His clutch is working fine and no probs at all there . . . but his bike is Busa fast as hell, he was side by side with me under full power in 4th gear, very impressive engines in those K1300S bikes.
Had a great time today and tomorrow is track day!

[rubbersidedown]

OK, so I went for a 200km blast today with the Beemer guy, Mike.
His clutch is working fine and no probs at all there . . . but his bike is Busa fast as hell, he was side by side with me under full power in 4th gear, very impressive engines in those K1300S bikes.
Had a great time today and tomorrow is track day!

Hey I've got an' idea!!! What say you just have all the fuggin' fun. EH. That OK with you? I mean I've got better things to do anyway. I'm gonna go eat the last of that cheese slice sandwich I made day before yesterday and curl up on the floor and cry myself to sleep again.


Awesome man...you deserve it,you bin working hard.

Besides...an' ol' fuddy duddy like you needs to take lot's of breaks.

Maybe you can catch a nap,you know,between laps at the track.
Remember,plenty of water and don't forget your Geritol.

Are ya gonna do it here...or tell me to go get fugged in a nice PM.
(as usual)
J/K mate...ride hard,ride fast...but keep the RubberSideDown.
I know you are fast,I would not want to chase you around.
Rubb.

[Cantab]

OK, so I went for a 200km blast today with the Beemer guy, Mike.
His clutch is working fine and no probs at all there . . . but his bike is Busa fast as hell, he was side by side with me under full power in 4th gear, very impressive engines in those K1300S bikes.
Had a great time today and tomorrow is track day!

The K1300R gave the BKing a run for its money as well...better ergos on the beemer.
Have a great day at Ruapuna mate

[Kiwi Rider]

Hey I've got an' idea!!! What say you just have all the fuggin' fun. EH. That OK with you? I mean I've got better things to do anyway. I'm gonna go eat the last of that cheese slice sandwich I made day before yesterday and curl up on the floor and cry myself to sleep again.


Awesome man...you deserve it,you bin working hard.

Besides...an' ol' fuddy duddy like you needs to take lot's of breaks.View attachment 1624093
Maybe you can catch a nap,you know,between laps at the track.
Remember,plenty of water and don't forget your Geritol.

Are ya gonna do it here...or tell me to go get fugged in a nice PM.
(as usual)
J/K mate...ride hard,ride fast...but keep the RubberSideDown.
I know you are fast,I would not want to chase you around.
Rubb.

Two words Canaduh . . .
Fug YOU ! ! !

[rubbersidedown]

Kiwi>

<Rubb.