Hydraulic Clutch Oil??

[jyellard]

Is there a special automotive grade mineral oil to put in the clutch? My local auto parts store doesn't carry any type of mineral oil, but my wife has some mineral oil she gave my son when he was constipated as a baby.

What do I put in my clutch?

Thanks,

Josh

[joey11]

I use Dot 4 brake fluid. Check the clutch res. cap. It should say Dot. 4 only. I thought the same thing when I got my 03 because the KTM's use mineral oil. The magura's are the only ones that use mineral oil that I've seen.

[Eric K]

First, read the cap on the master cylinder reservoir.

The early ones used DOT 3 or 4 brake fluid.

The newer ones use mineral oil.

[jyellard]

The cap says to use mineral oil.

Is this the mineral oil you get at the drug store, or is it some special automotive / clutch grade of mineral oil?

[GMP]

The later bikes that use mineral oil are marked on the master cyl cap, and the cap should be green. Both older(DOT 3/4 brake fluid) and new masters are AJP, but I'm sure the seals and pistons are different materials. For oil, any light petroleum based oil is fine. Shock/fork oil, or hydraulic jack oil works great.

FYI, on my '07 the clutch slave cyl has no retention circlip for the piston like my older bikes did. I suspect this is to eliminate possible breakage if the lever is pulled with the slave off the motor. What this means is that if you remove the slave, the piston return spring will eject the piston and drain the oil, requiring filling and bleeding. To avoid this carefully retain the piston in the slave with a small clamp/clip when it is removed.

[MattR]

You can also use ATF. I did this on my KTM and it worked well. The fork oil is probably the better route since you can buy a very low wt. oil.

[jyellard]

That was exactly my problem, GMP. Went to install an LTR slave gaurd on my 07 EC300, and the spring kept pushing out the piston. I kept bleeding the slave to push the piston back in and wasn't quick enough to reinstall the slave assembly before the spring pushed it back out. After numerous attempts I got it reassembled, but now I need to fill and bleed the clutch system.

Anyhow, I bought some Motorex clutch fluid from my local KTM dealer. Question answered.

Funny side note, the guy at the KTM dealership asked what bike I was putting the oil in. I told him a GasGas, and he had never heard of it. True motorcycle aficionado!

[LAWMAN]

I put drug store mineral oil in a KTM once in a pinch, it worked fine. + if you get to feeling "irregular" while out on the trail, there you go!

[GMP]

The term "mineral" oil relative to the clutch fluid simply means petroleum based hydraulic oil. No synthetics or other hydraulic fluids, as there will be seal compatibility issues. Since the first juice clutch KTMs in '98 hydraulic jack oil or non synthetic lightweight fork oil has been fine. ATF works OK too. The jack oil is very light, cheap, and found in any auto parts store.

[jyellard]

Thanks. Next time I'll buy some hydraulic jack oil.