Anyone know which way round the seal sits in the caliper? The seal has a small groove around the circumference on one side, does this groove face toward to piston or face toward the caliper body? Deos it matter?
Yes it matters, if you put it the wrong way then fluid pressure will try to collapse the lip, causing it to leak. When it's fitted correctly, the fluid will try to expand it (think wind behind an umbrella), causing it to seal more tightly.
So the groove should face toward the caliper body then?
where did you get seals from?
Groove is on the fluid side.
Seal is the original, I took it out to inspect for damage (found none). Popped in a hope mini seal, which did the trick for a few days before swelling up. Resigned to putting the original seal back in and living with a imperceptible leak until I can get a fix or its new brake time.
Resigned to putting the original seal back in and living with a imperceptible leak until I can get a fix or its new brake time.
You will very likely find the leak is worse than before. Any caliper seal tends to get damaged as it is removed.
could you post a picture of the seal and which brake it is? I am determined to find the seals somewhere but don't want to take mine (XT 775) apart while they work.
Sorry brakes now assembled again and fully bled, don't really want to take them apart if I can help it. They are M775 BTW, leakage with these seems to be quite common.could you post a picture of the seal and which brake it is? I am determined to find the seals somewhere but don't want to take mine (XT 775) apart while they work.
I was very careful and used a soft plastic tool from work to remove the seal. Inspection showed that it was in pristine condition, perhaps the fault is with the seal seat on the caliper?You will very likely find the leak is worse than before. Any caliper seal tends to get damaged as it is removed
Anyway, it seems to be holding up so far (cetainly no worse leakage than before) I will report back in a couple of weeks
there were a few cases* of shimano calipers going a bit leaky in cold weather - this was a couple of years ago.
is this a possible explanation?
(*me included, it seems i've got a set of brakes for 'summer use only'...)
I'd like to know if the ones that leak have been used with the wrong fluid - ie type or viscosity. (as I have a set)
My Xt775 developed a seal leak too, they are currently in the spares box so will be very much interest in finding a seal that fits to repair them.
The ones that leaked had faults. I'm sure my slx are the same as the bike sat there for months in the shed last winter,it was fine until I took it for a ride and found the disc damp with fluid. The calliper had a wet look mist over it too,just like you'd expect from a leaking calliper.
I cleaned it down and replaced the pads, it was fine. It sat there for a week or so and I took it out and it was the same again. Calliper looking misty with a howling brake. I'm certain the cold shed/sub zero temps cause the probs. It's fine through summer!