Raptor Chapter

pod wrote:55 years agoAn excellent write up on brake bleeding,
most important two positions for elevated rear caliper

http://www.apriliaforum.com/forums/show ... hp?t=15500

Ive just followed this method, position 2 for the caliper got the last bit of air out, I now have a solid pedal and a good rear stopper.
Now out for more fun.

Note to moderator, the link should be a sticky in the tech section, could save folks a lot of grief, the Mille people have an identical rear brake.
Cheers
Pod

More information here....

http://raptors.ukbikeforum.co.uk/viewto ... 44e3c631ca

This here is the best position for the Rear caliper when bleeding it of air. The caliper is repositioned on it's mounting bracket by passing it between the swingarm and wheel spokes. Much easier than bleeding the caliper on it's bracket.

Just an update on rear brake bleeding issues. 45,000 miles on.
Every year after a winter lay up I have had to bleed the system to restore function.
Yes I have taken the caliper off and bled it upside down and always get a firm pedal after , but the air has always found its way back in eventually.
After reading through the Aprilia link ( all 14 pages!) it seems that if you have this problem it is a faulty master cylinder.
The nice man at "Bike torque racing" has new brembo stuff , sadly only complete units no rebuild kits.
They also have brake banjo bolts with a bleed nipple , so Im fitting one of them as well.
Some people on the Aprilia forum reccomend drilling out the plastic L shaped connector from the reservoir to the master cylinder from 3mm to 4.5 mm inside diameter, reportedly giving improved braking performance, I will try this as well, will report once the bits are fitted.
A new rear master cylinder is about 37quid, I am also replacing the rear caliper because of corrosion on one of the pistons which sticks badly.
Aprilia milles used the same rear caliper , got one on ebay for about 40 quid, they are about £80 new.
HTH
Pod

hey I had the same problem when I bought a new rear cylinder from Bike Torque racing as well - however they insisted Brembo are never faulty! After several hours on the net and messages later I found Mode Performance, who are Brembo in the UK, and contacted Ian who tested the 'faulty' cylinder declared it ok but still replaced it. My dad said it was air passing by the lower seal into the cylinder as there was no leaks anywhere.

Mode Performance are at Silverstone and do a recon kit for the calipers - however if you know the piston size it shouldn't be too hard to size up a replacement piston and seals, which may be cheaper than whole new unit

Nice tip for Mode racing , will give them a call.
Cheers
pod

Job done, new caliper and M cylinder fitted, I didnt drill out the L fitting cos on the Cagiva its a straight piece, had to swap this over from the old mcylinder.
Bled and tested great, feels much better than before, passed the MOT today, woo hoo.
Cheers
Pod

The resurrection of this topic reminded me finally to do something after, once again, a total loss of the rear brake at an inconvenient moment.

I went for KZMille's two-position technique described in the Aprilaforum link. Actually, I bled the brakes in both positions more than once, just to be sure. I also tied the caliper up as high as possible, just under/by the rear frame tube (the plastic in-fill piece under the seat had already been removed for repair, which helped). This results in the brake hose rising directly from the cylinder and having no possibility of trapped air (unlike Carnivore's technique - see photo above). I used the thick flat of a large open-ended spanner to keep the pads from closing and secured that in the calliper with more string.
Seeing as the brake fluid was supposed to have been changed in the major service I forked out for last year, I was not impressed to have to top up the reservoir three times (it may even have been four) before the brake pedal firmed up, then a final top-up. On the other hand, it was rewarding to see so much air coming out. I'm amazed that the brake worked at all.
BTW, that little black rubbery bellows thingy just underneath the reservoir cap threw me at first, until I realised it was just a kind of protective cover. Well, I assume that's all it is. You do have a little black rubbery bellows thingy, don't you?

Having read KZMille's explanation for the two-position technique in the Aprilaforum, I cannot be sure that Carnivore's single position is adequate. Just saying.

Anyway, the brake feels really solid now. Definitely worth doing.

please someone tell me that Cagivas rear brake is not shitty like Aprilia Milles. cuz Mille was notorious with the rear brake being placed in the wrong position and the master cylinder being too closed to the exhaust causing the heat to make bubbles in the brake fluid... Thats why many people and I had to keep bleeding once a week or so . A lot of people stopped using the rear brakes .. Cagivas rear brake is solid and I hope it doesnt require special instructions to bleed it like that cuz I got used to bleeding my brakes with an equine syringe without removing. These are Brembos for crying out loud not generic chinese calipers Aprilias rear brake was really pathetic. Excellent bike but the crappiest rear brake I have ever seen on a bike! under powered and placed in the wrong spot on the bike.
I like the cagiva so far only the side stand sucks like a 7 year old designed it. I hope that same kid didnt touch the rear brake because I love my rear brake and dont want any issues with it at all

Wish I'd read this a while back,
After many minutes of pumping (ooh, err, sounds a bit rude!) I got mine bled in seconds with the Brembo on the pillion seat! I think air gets locked after the master cylinder and stretching the brake hose up releases this.

Holy thread revival raptorman Fitted my goodridge limited edition rear brake line after snapping the banjo on the oem piece of shyte. Bled the rear caliper by lifting the caliper above the master about seat height and bleeding with bleed nipple at the top tilted forward and then backward works a treat. My brakes are solid and have never felt better, no more squishi .

If I remember rightly, I couldn't bleed the back brake at all until I sat it on the seat of the bike, when it went a treat.
I must have tried this in desperation but it worked.

This so works.. was a last resort and now got rock hard rear brake!!!