[donnaiwanna]

Ok I have no clutch due to the fact that i assumed it would be a good idea to use mineral oil in place of DOT 4. The question I have is where does my repair to my clutch system begin and end I know I have to replace the slave cylinder seal and the reservoir gasket. What about the clutch-lever seals and the clutch pressure line?

 

[DanDiver]

I know absolutely nothing about it, but from a gut level, maybe try flushing it with DOT4 and then replacing the mineral oil with DOT4 just too see what happens. Probably can't get much worse.

BUT please get a more knowledgeable person to respond before trying this.

As I said, I don't know and I didn't stay in a Holiday Inn Express last night either.

 

[Voyager]

I know absolutely nothing about it, but from a gut level, maybe try flushing it with DOT4 and then replacing the mineral oil with DOT4 just too see what happens. Probably can't get much worse.

BUT please get a more knowledgeable person to respond before trying this.

As I said, I don't know and I didn't stay in a Holiday Inn Express last night either.

Yes, I would give this a try also. I have no idea if the swelling is reversible, but given the effort required to get to the slave cylinder, I'd invest a liter or two of DOT4 first.

 

[jzeiler]

You can give it a try but I would not expect it to work. Like I listed in the earlier post here are the items you need to replace:
32 72 2 333 063 RUBBER BOOT 1 $9.69 May be OK

21 52 2 333 433 OUTPUT CYLINDER CLUTCH A Must 1 each $146.03
32 72 7 665 445 MAINTENANCE KIT, PISTON -A Must 1 each $72.38 to rebuild the master cylinder

The hoses should be fine, just flush them out good with DOT 4 before you replace the parts.

- no kit for the slave, have to replace the unit. You have to pull the swing arm to replace the slave cylinder. Take a look at the Weep Hole video in the sticky at the top of the page to see what is involved there.
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[saddleman]

I would NOT try the Dot 4 until you have least removed the slave cylinder and checked it for a leaky seal. If the slave cyl. seal is bad you will be pumping the new Dot 4 into the clutch area.

 

[DanDiver]

Listen to Dave and John - THEY know what they are talking about.

 

[rdwalker]

Actually, I'd first replace the small items and flush the system, before going for the big bucks.

Reason? Mineral oil (of which baby oil is a variety, for example) is a fairly mild substance. Chances are that it leaked out or is not creating pressure because the seals are not swelling the way they do with DOT4.

A double flush may get you up and running. Worth trying; just watch that the slave piston is tight and the replacement fluid does not piss out into the clutch itself.


Now, the other way around (that is, putting DOT4 into mineral-oil based clutch systems, such as in R12-bikes) would be a true disaster. DOT4 is nasty stuff.

R.

 

[andres]

I once removed the O-ring "gasket" from a R1100S fuel tank to replace the filter, and could not get the O-ring back due to it being swollen. I washed it with soap and water and left it to dry, and a week later it had shrunk to the extent that it could be re-installed and it functioned without problems. I've done this twice with the same results. The swelling is a natural phenomenon and aids in the sealing action, and in some instances may be reversible. I would however not recommend this for a brake or clutch system, and doubt if it would yield similar results.

The rubber seals in a brake/clutch system designed for DOT 3/4 fluids are most likely EPDM which is not resistant to mineral oil. The swelling is a result of the rubber absorbing the oil, and leads to a change in the rubber's mechanical properties such as becoming softer. It would be difficult if not impossible to "extract" the mineral oil from the rubber seals, and even then the rubber may have permanently changed its properties.

However, not to confuse the issue, the advice given by John Zeiler is correct. You will have to replace every seal from the master cylinder right down to the slave cylinder, in fact you should replace every rubber part that was in contact with the mineral oil. I would be hesitant to retain the contaminated hoses, since depending on the construction thereof it may use EPDM liners which would also have absorbed the mineral oil. Once refilled with DOT 3/4 the mineral oil may be released to contaminate the new DOT 3/4 fluid. Some publications recommend that rubber brake/clutch hoses be replaced after 6-10 years, so it may be a good time to get that done too. In for a penny, in for a pound!

 

[JPSpen]

:corn:


John

 

[deputy5211]

And if you choose to replace the rubber hoses with the same, I believe I have some used ones you may have for the price of postage. Just pay it forward to the next person some day.