bleeding brakes!

[xpress]

hi there, bleeding the brakes after a couple of front pipes were replaced. there was still a lot of fluid left in the system before bleeding, the master cylinder looked pretty full. i started by bleeding the back wheels with a mixture of the bmc "drink tea syphon system of bleeding" (not sure i am able to make the bmc syphon method work!) and the old fashioned up and down and then the new front pipes filled up with fluid and then i carried on expelling air with the master cylinder cap off all the time, an open tube from the bleed nipple in some fluid and the up down up down method of bleeding the brakes.

however, the brakes are not coming on fully even with the pedal to the floor, i presume there's still air in the system. however the pedal is starting to return, with the pedal to the floor they're starting to come on. i must have put 0.4 litres through all bleed nipples there but still there must be air in the system.

i've managed it before, i just have to keep persevering!

how much fluid do you normally put through the system to bleed it of air? maybe i need to go round all wheels and pedal once or twice with each and leave the air to come out with the syphon method for ten minutes at each wheel with the master cylinder cap off and keep topping up the master cylinder as i go around each wheel? fourty minutes to do the whole lot? or should i be passing more brake fluid through the system with the up down up down method?

[bmcecosse]

It generally just takes me two cups of tea to do the lot...........

[chickenjohn]

Best way is to use a pressure bleeding kit with a specially modified cap from an old master cylinder.

[xpress]

Hi john. How much fluid do you run through with the bleeder?

[xpress]

Maybe some truth to bmc tea drinking bleeding.

i have been bleeding the air from the system with the master cylinder cap open, and i believe it expels some air that way, and also taking off the bleed screws helps too.

I was getting nowhere fast with a new non return bleed hose today,it was too short, kinked, and no fluid was coming through it. The normal hose in fluid and bottle method was fine yesterday for refilling the system but brakes were no coming on fully. Today I took a nipple off the back because it felt a bit gritty, dabbed a bit of grease on thread and put it back in. As a side effect, hey presto good pedal. Opened up front nipple same thing. Job done.

[bmcecosse]