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One of my brakes suddenly went to the bars between rides. It was working fine, then next ride seemed to be full of air. No sign of any leaks.
Just bled it, indeed it was full of air, and now it's totally fine.
So, my question is, why did it suddenly get air in it, when there apparently no leaks?
low level in the resovoir?
Dot fluid is hygroscopic,it absorbs moisture from the atmosphere.Even in a closed system it will eventually become contaminated.This will lower the boiling point and when the pads get hot enough the heat will boil off some of the fluid,converting it into a gas.And you get air in the system.
IIRC 😉
The air would have got in gradually but would have been trapped in the reservoir. You must have knocked the air out of the reservoir and into the main system, making you think that a load of air suddenly got in.
Dot fluid is hygroscopic,it absorbs moisture from the atmosphere.Even in a closed system it will eventually become contaminated.This will lower the boiling point and when the pads get hot enough the heat will boil off some of the fluid,converting it into a gas.And you get air in the system.
True ish - the water turns to steam when the brakes get hot and will turn back into water when the system cools down then the brakes will start working again.
low level in the resovoir?
Nope, the reservoir was full.
Mineral oil btw (magura), not DOT.
I've got 975 XTRs. It's been two times now that they were "suddenly" up against the bars between rides. Just as you describe.
2nd time it happened I noticed an oily lever. There must be a leak in the lever area, oil gets out, air gets in when I put the bike upside-down for a repair/clean.
Maybe same with yours?
So is mineral oil (only less so).
I've got 975 XTRs. It's been two times now that they were "suddenly" up against the bars between rides. Just as you describe.
2nd time it happened I noticed an oily lever. There must be a leak in the lever area, oil gets out, air gets in when I put the bike upside-down for a repair/clean.
Maybe same with yours?
that'd be my [s]bet[/s] guess - air in reservoir redistributing when the bike's upside downair gets in when I put the bike upside-down
Bike never really goes upside down. It's stored upright in the shed, and travels upright on the roof rack of he car, so I'm not sure that's the answer either.
Just seems a bit wired that air seemed to get in without any noticeable leak of oil out.
I had that with some Marta SLs once - they were absolutely fine then just kept randomly pulling to the bars once to twice a ride. I spoke to the chaps from Magura at Mayhem who just said "yah zeh do zat". That's fine then...
GB
zat kant be fine, kan it?! it mite be ze vrong moment... 😕 🙂
Why don't you drop us an email??
Service Centre email is:
magura@racemechanic.co.uk
We'll see if we can help you.
Thats it their 'wired'.