Raptor Chapter

Hi all I have a 2003 V raptor
Been on it this pm and lost the back brake after loads of use
Completely gone no pressure building up at all, no external leak
Ten mins later it started to come back, seemed fine, I assumed it was brake fade as the calliper was red hot, so thought best to change the fluid
Just changed the fluid and now I can't seem to bleed the system,
Do they struggle to get the air out?, Ie can air get trapped in the calliper etc?
Or is it seals?
Any ideas??
Thanks
Gareth
Ps brembo brakes

Mine did the same, air gets trapped in the caliper, even with a bleed, I took the caliper off its mount and suspended it after pushing the pistons in, and bled it while turning it different orientations, this cleared the air, job done.

It will get hot and fade out with air trapped in the caliper, or moisture, the pressure build makes the pistons push out, so you have a dragging brake, which heats up and fades to nothing, when it is cool again you will have pedal, but a spongy one until bled through.

Hi, there are lots of posts on this problem

http://www.raptorchapter.org.uk/viewtop ... eed#p33141 might be a help?

if you succeed in bleeding it correctly and its still crap, then probably the master cylinder is faulty.
its well documented, a new one sorts it out, i dont know why they were so duff, i couldnt find anything obviously wrong with mine but it was pretty scubby, I suspect the internal non return valves get gummy and fail. replacements work fine. i ended up changing the rear caliper as well, sticky pistons dont help here.

Thanks very much for that
I've bled it a few times now using a vacuum bleeder
Pulled at least 2 litres of fluid through it
Still can't get a pedal
Weird as it was ok after fading once I let it cool down? After bleeding the old fluid out I can't get anything??
Where would I buy a new master cylinder and possibly a calliper?
Thanks again
Gareth

Have you bled It with the caliper up in the air with nipple to the top?
They are a pig.

No it's been bled in situ using a vac bleeder
Loads of fluid through but still no pedal
Have heard a few different ways of positioning it
Any thoughts?
It's a pain!!

I tried all those fancy bleeders and it never worked properly but by removing caliper and clamping it in my workmate bench with the bleed nipple uppermost it proved successful!

Make sure you put something between the pads first!

Also those symptoms can also indicate a MC fault, I had that many years ago and had to buy a new MC, which fixed the issue but still had to bleed using the work bench.

All
I really appreciate your help
I can't make out how something so simple can be so complicated?
Flaming murder
Thanks again
Gareth