Bleeding a radial master cylinder

[Cajun]

Okay i have jsut got some new brake lines, on (changed from stock setup[1 line at m/c], net setup[two lines coming off m/c])

and i am having a really hard time to get them bleed up,

I know you need to bleed up the m/c

Which i believe i have done, Put finger over the hole where lines bolt up, and pull brake lever, and release the pressure, to try and get fluid flowing, which i have done, then i bolt the lines to the m/c then to the calpiers, and then i can pull pull lever as much as i want and doesn't seam to do jack.

I don't have a vacum bleeder i only have one of the old style normal bleeder system with a two way valve.

Anyone have any idea what i am doing wrong?

[dhunt]

Okay i have jsut got some new brake lines, on (changed from stock setup[1 line at m/c], net setup[two lines coming off m/c])

and i am having a really hard time to get them bleed up,

I know you need to bleed up the m/c

Which i believe i have done, Put finger over the hole where lines bolt up, and pull brake lever, and release the pressure, to try and get fluid flowing, which i have done, then i bolt the lines to the m/c then to the calpiers, and then i can pull pull lever as much as i want and doesn't seam to do jack.

I don't have a vacum bleeder i only have one of the old style normal bleeder system with a two way valve.

Anyone have any idea what i am doing wrong?
What I've done in the past is squeeze the brake leaver and loosen the top banjo bolt (Put a rag round it to catch the brake fluid), tighten and repeat. Should only take a couple goes before you should notice you've got lots of pressure.

Don't worry about the calipers etc until you get you get pressume on the lever as it won't make any difference at all.

Doesn't your radial MC have a bleed valve? If so that might work as well.

[Cajun]

yeah it has a bleed valve, that doesn't seam to make much effect either.

off to try something else i jsut read up about

[imdying]

Which i believe i have done, Put finger over the hole where lines bolt up, and pull brake lever, and release the pressure, to try and get fluid flowing, which i have done, then i bolt the lines to the m/c then to the calpiers, and then i can pull pull lever as much as i want and doesn't seam to do jack.What you're doing here is ensuring that the master cylinder fills with fluid. When you release the lever, the bore needs to fill with something... because you're got your finger over the outlet, it can only draw from one place, the reservoir, which ensures that the master cylinder is 'bled' or 'primed'. It should only take three or four strokes to accomplish that.

Next connect the lines to the outlet, then repeat the process, but instead of blocking and releasing the pressure at the outlet of the mcyl, you're doing it at the end of the lines that'll be connected to the calipers. Will probably take 6-8 pulls a line. Many (most) systems don't even need that step, and can be bled from the caliper straight away.

Once you've got the lines partially bled up, and the mcyl bled up, just hook the lines up the calipers, and pump away, probably use about 250ml of fluid. The open shut bleeding with the calipers bleed nipple is really only a finishing touch if done correctly.

Do consider that the mcyl may have been assembled incorrectly... it's a trivial task to disassemble and check it.

[dhunt]

yeah it has a bleed valve, that doesn't seam to make much effect either.

off to try something else i jsut read up about
Try bleeding it at the banjo bolt like I suggested earlier. That has always worked for me. But the 1st couple pulls you probably won't get any fluid or very little then it will suddenly go hard. Have fun :yes:

[Cajun]

yeah i have tried the method you pm me other day imdying, not much like

friend who who is use to work at a bike shop in the workshop come give me a handy tomorrow i had not much luck. most likley user error,

Never had any problems with fitting brake lines before, just this damn radial m/c just does not like me.

[imdying]

It may simply be faulty :( Where did you get it from, somwhere local? If you are able to prime the mcyl, then it is unlikely to be faulty though. You may just need a second pair of hands to ease the load.

[sAsLEX]

Best thing I have ever used was this http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=42611&d=1159167365

Designed for an old British car some No 8 wire got it on to the reservoir and forced the fluid through, was taking way too long after stripping the brake callipers and fitting new seals so the system was completely dry.

[Cajun]

Thanks to a mate, got it sorted

he bleed it by pumping fluid from the nipple at capliers up the m/c, and once that is done, start bleeding via the normal method,