bleeding my rear brake

[kriss]

i know this has been gone over and over but if i dont get help soon ill go mad. my xl1200r rear brake felt spongy and did have bit of travel so decided to bleed or attempt to bleed it but bad move because as soon as i try to pumpthe peddle it just sucks fluid back up pipe before i can do anything about it,. now ive had bikes for 40 years and never had probs bleeding brakes before so what am i doing wrong ??. the nipples on this bike back and front dont seem to be a very good fit and am wondering when i turn nipple to pump peddle air is bypassing nipple. my lacal bike shop says it could be the mc but dont want to fork out good money if it only needs bleeding,

[Ukkid76]

I have found the only to bleed brakes on motorcycles is to use a syringe, if you do a search on here you will find a thread with the correct procedure on it, there is an easy to do it.....

Good luck..

[Urrell]

Would this be a 2004 or 2005 bike?

Those years have a big problem with the rear master cylinder rubber seals breaking up giving the symptoms you describe. Have a look in the brake reservoir, Are there any orange globs in there?

If so you may have to have the master cylinder rebuilt with a rebuild seal kit.

[kriss]

thanks dave and urrel, no globs mate no. if i tried to bleed once i tried 10 times and no luck. ive blead brakes all my life without any probs at all like this. i conect pipe to nipple and then put other end in jar with fluid in and when my mate pumps before i get chance to close nipple it just sucks itself straight back into caliper. sometimes when you pump fluid will come into pipe then it just comes to a stanstill and nowt comes out dispite reservoir being full so maybe its the mastercylinder not doing its job. price to buy plus fit £130. im not really worried about the money side of it i think im more peed off at not being able to suss what the prob is. thanks guys for your advice/help sorry urrel bikes a 2004 so you could be right and new mc ordered, cheers mate

[krull]

I had an absolute nightmare when I put dot 4 fluid in, so had to completely drain the system and refill.

I eventually bought one the pressurised bleed pumps. Did the job in 5 minutes using it.

[kriss]

Originally Posted by krull

I had an absolute nightmare when I put dot 4 fluid in, so had to completely drain the system and refill.

I eventually bought one the pressurised bleed pumps. Did the job in 5 minutes using it.

would you like to come and do mine ? ill even make your tea

[Urrell]

I'm sure you will have to sort the master cylinder before you get anything thru.
Think the seal breaks up and blocks a very small transfer port.
Could have had a rebuild kit (42810-04b) for about £30 and some DOT5 brake fluid.

Hope you get back on the road soon.

[FXSTC Dave]

Hi.

I used this when I changed to Goodrigde braided hoses.

Try you local motor factor shop, you may get it cheaper
that it says here.

Draper Tools Online Product Inquiry

[b0nio]

There can be an air lock in the area of the brake light switch where the line has a high point and then drops down to the swingarm. My method is to take the caliper off the bike, take off the clips and fittings unfasten the switch, and lift the caliper to the highest point you can get it and get the brakeline so that it's always rising towards the caliper to avoid air locks. with a bit of luck any air in the system will rise to the caliper and bleed out. I use a vac pump because the MC, unlike a car, doesn't pump enough in one shot to push any air out of the system. It's easy to imagine the MC is faulty but if the MC was ok before??

[Limey_Dave]

Spongy pedal followed by problems bleeding is classic sign of seals going and or faulty internal spring.
If recovery hole isn't uncovered when piston returns then you don't pump a second charge of fluid.
No MC I've ever seen will displace enough fluid with one pump to fill a system thats lost fluid,it's designed to move enough fluid to move pads that are only just clear of the disc.