XT brakes spongy after bleed

Mc Smiley

Brakes still don't get firm again, both brakes similar although the rear is worse than the front. Have bled from the caliper and made very little difference. System seems to be losing a lot of oil, possibly from the lever?

was just wondering is it time for new brakes or is there some fix?

Thanks in advance, Nyle

supersonic

If the seals are shot, they need replacing.

Tap the caliper as you bleed, can free trapped bubbles.

cooldad

If they are still spongy = bled badly.
Unless the system is leaking - surely if it's losing a lot of fluid you can see where it's leaking, either the lever or calliper?
Or does it just need fluid as you've let air out leaving space?

02gf74

XT disc brakes have a great feel - some softness then solid as a rock once the pads are on the disc - so you have air in the system.

They are also the easiest to bleed (you don't say whcih model but I refer to the older ones with the reservoir llid).

The way I bleed them is to loosen the lever clamp and position so the reservoir is horizontal, Squeeze lever then open and close the bleed screw. Release lever. Repeat topping up the fluid after 2 or 3 strokes top avoid air getting into the system.

Mc Smiley

Supersonic I feared that, have tapped it, bled twice, by me and by a friend and same result both times. We aren't pro mechanics but I have bled avids before with no trouble. There seems to be fluid leaking around the lever area... and only comes out when braking.

No way air has got in, used different bleeding methods, like pushing fluid in from the caliper and out the top.

If the seals are shot would it be alright to guess that the levers are the problem and calipers are fine to keep/sell?

cooldad

You can get replacement seals for the levers.

02gf74

If fluid is coming out when you apply the brakes, then the lever unit is faulty. Likewise if fluid is coming out of the hoses or caliper, that too is faulty..... unless ofcourse it is where the hose meets lever or caliper in which case the join may not be done up tight enough.

Mc Smiley

Yes they are 775 ones a few years old, with the resevoir top cap and servo.I realise they are easy to bleed and now how they feel and therefore realise they have air in them...

I will check it isn't in the join between the hose and the lever.

Where can you get new seals from?

cooldad

Madison, your LBS or Google.

mister p

You can get the rubber diaphragm that sits under the top cap but that is the only seal you can get for those. Without knowing exactly where the fluid is coming from it is difficult to diagnose if the levers are shot or not.

Can I ask why you bled them and what they were like before the bleed?

Mc Smiley

Because the brakes didn''t stop me as the lever s reached the bars.

mister p

OK, that does sound like a leak somewhere then. Best to clean everything up, make sure there is no fluid on the levers and work out where the leakis.