clutch master cylinder, help..

[gazulu]

, evenin all, set about replacing said master cylinder, bolted and connected everythin back up, depressed the pedal to find it stayed down and had to be manually pulled back up, accompanied by a loud clicking noise noticed that when i slackened the fixin bolts a tad, pedal returned as normal,but with no clutch resistance whatsoever, tried bleeding system, and not even getting fluid through, even put old cylinder back on but still got no clutch resistance at all, not even gettin fluid through with the banjo disconnected, supposed to be a straight forward swap and bleed i thought any help will be gratefully recieved, against the clock, as sposed to be goin to vanwest fri, heeeeeeeeelllppp....

[Ian Hulley]

Tap the pedal, the things normally self-bleed. Air bubbles are trapped in the cylinder and they need to be coaxed upwards and out.

[California Dreamin]

These normally gravity bleed but if you are having problems it might be useful to buy or loan a pressure bleed system.

Martin

[gazulu]

thanx for the rapid response ian and cali, what ive noticed in the haynes manual, is the pushrod is shown to be straight !!! whereas my pushrod is bent or offset which is right ??? if it is offset, could i have rotated it somehow,changing the angle, thus causing that binding spot on the pedal travel to occur when i tighten fixing bolts up, thanx again lads, shall try the tapping method tmorra night , when i resume play

[mark]

it sounds like you havent got the plunger (for want of the right term) in the top right its not bent or off center iirc, i couldnt get mine to gravity bleed, and i left it over night, but i changed all the fluid, the clear plastic pipe/hose that attaches to bottom was full of bubbles, one tip is keep an eye on the fluid level as one pump too many means start again and some numpties even have to start twice

mark

[California Dreamin]

I have done one of these many years ago but can't honestly remember the push rod. However, I think it is most unlikely to have a bend in it and unless there is a very clear reason that it should be cranked I would say that this is wrong.

Also...if you think about how the master cylinder works, the piston has to be able to return FULLY, in order for the port to be uncovered to the resevoir, and for fluid to freely flow through the cylinder into the hydraulic pipes.
If the rod is bent the piston may not be retuning fully and not allowing fluid to 're-fill' the cylinder chamber.

Adjustment should also be set in the rod so that there is a small amount of clearance before the piston is touched to ensure it fully returns to it's stop and the internal port is fully exposed to the brake fluid.

Martin