stuart Posted April 16, 2016 Report Share Posted April 16, 2016 Thanks, I'll give that a try and if not then return to current setting, it does feel like cylinders pushing against air! Thanks If it feels slightly spongy then pump the pedal a few times and without releasing it jam it down with a length of wood against the seat, leave overnight and then see what you have. Stuart. Quote Link to post Share on other sites
grumpy2 Posted April 16, 2016 Author Report Share Posted April 16, 2016 Hi. I don't think the air is in the pipes with the fluid. I think it's like the cylinders have a lot of travel before the shoes touch the drums. I'll have a fiddle later. Quote Link to post Share on other sites
Peter Cobbold Posted April 16, 2016 Report Share Posted April 16, 2016 Hi. I don't think the air is in the pipes with the fluid. I think it's like the cylinders have a lot of travel before the shoes touch the drums. I'll have a fiddle later. Try stamping on the brake pedal hard after readjusting the shoes, then adjust again. Quote Link to post Share on other sites
Guest ntc Posted April 16, 2016 Report Share Posted April 16, 2016 If it feels slightly spongy then pump the pedal a few times and without releasing it jam it down with a length of wood against the seat, leave overnight and then see what you have. Stuart. +1 and if that does not work you need to pressure bleed it. Quote Link to post Share on other sites
poolboy Posted April 16, 2016 Report Share Posted April 16, 2016 Hi. I don't think the air is in the pipes with the fluid. I think it's like the cylinders have a lot of travel before the shoes touch the drums. I'll have a fiddle later. That's adjustable. Quote Link to post Share on other sites
Peter Cobbold Posted April 16, 2016 Report Share Posted April 16, 2016 Hi. I don't think the air is in the pipes with the fluid. I think it's like the cylinders have a lot of travel before the shoes touch the drums. I'll have a fiddle later. The garage adjusted the shoes with handbrake disconnected. So the cylinder may well have been disturbed when the lever was refitted, giving the long pedal travel. I adjust the shoes with h/b connected, and work it hard on and off, also bang on the pedal hard , to recentre the cylinder and shoes to get the best adjustment. A lot of force can be neded to make the cylinder slide in the backplate, if its stickng lubricate the sliding surfaces. Peter Quote Link to post Share on other sites
grumpy2 Posted April 16, 2016 Author Report Share Posted April 16, 2016 Had a fiddle tonight (wild Saturday night here) with minimal improvement. Brakes well adjusted, one notch to locked, power is good, pulls up straight and true. Fast stop and and I don't think there's any reduction in effectiveness (well they did pass the MOT yesterday) but the pedal travel is still long Trying the pressed pedal thing overnight but with little optimism So in my head I have 4 thoughts, leave it and get used to it, put new seals in the old MC and put it back on, buy another new one and possibly return the old new one as faulty, go back to paddocks and see what they say. Quote Link to post Share on other sites
stuart Posted April 17, 2016 Report Share Posted April 17, 2016 So whats it like today after jamming the pedal down over night? Stuart. Quote Link to post Share on other sites
grumpy2 Posted April 17, 2016 Author Report Share Posted April 17, 2016 Rubbish. No different. Brakes work ok but pedal travel too long. First press very long second press shorter but still too long. More fiddling I think. Here a theory. If there rear shoes are significantly out of adjustment the first press pushes the piston out to make contact with the drum. A rapid second press doesn't give the fluid enough time to return to the MC so is a shallower press on the pedal. Waiting anything over 10 seconds and the travel is long again as the fluid has returned to the MC. Brakes work well as there's no air in the system. Could a similar effect happen with s duff MC ( even though it's new we all know that new parts are of dubious quality) ? Ta Quote Link to post Share on other sites
RobH Posted April 17, 2016 Report Share Posted April 17, 2016 Just a thought - I wonder whether the new MC and slave cylinders have the same bore as the old ones? Smaller MC or bigger slaves would give longer travel. Also you are assuming that the backing off problem is with the rear brakes but you tell us that the adjustment there is already tight 'one notch to locked'. Bear in mind that you can get pad knock-back at the front which will increase initlal travel. Quote Link to post Share on other sites
grumpy2 Posted April 17, 2016 Author Report Share Posted April 17, 2016 I only say rear as the front hasn't been touched so should be the same as before. I would say the the efficiency of the brakes is about the same as before but the pedal travel is too long. Quote Link to post Share on other sites
stuart Posted April 17, 2016 Report Share Posted April 17, 2016 Have you checked pushrod clearance on servo to MC. Stuart. Quote Link to post Share on other sites
grumpy2 Posted April 17, 2016 Author Report Share Posted April 17, 2016 How? Quote Link to post Share on other sites
graeme Posted April 17, 2016 Report Share Posted April 17, 2016 Sounds very much like air trapped somewhere. I would try bleeding again or even pressure bleeding. Graeme Quote Link to post Share on other sites
grumpy2 Posted April 17, 2016 Author Report Share Posted April 17, 2016 Graeme spent the second half of the afternoon doing just that. Hadn't used my easibleed as the MC lid is too big. So I adapted the one from the old MC and decided to pump a litre of fresh fluid through the system. No bubbles came out of the rear cylinders BUT....... after about 15 seconds a single huge bubble came from the front near side, then nothing more. No bubbles from the offside. The pedal now is strong and biting point where it should be, travel nice and short. Result thanks for all the advice and pointers, ready for 'drive it day' next weekend now, phew. Gary Quote Link to post Share on other sites
John Bracher Posted April 17, 2016 Report Share Posted April 17, 2016 Don't you just hate 'trapped wind'......! :lol: Quote Link to post Share on other sites
Guest ntc Posted April 17, 2016 Report Share Posted April 17, 2016 Graeme spent the second half of the afternoon doing just that. Hadn't used my easibleed as the MC lid is too big. So I adapted the one from the old MC and decided to pump a litre of fresh fluid through the system. No bubbles came out of the rear cylinders BUT....... after about 15 seconds a single huge bubble came from the front near side, then nothing more. No bubbles from the offside. The pedal now is strong and biting point where it should be, travel nice and short. Result thanks for all the advice and pointers, ready for 'drive it day' next weekend now, phew. Gary Told you so Quote Link to post Share on other sites
grumpy2 Posted April 17, 2016 Author Report Share Posted April 17, 2016 Two, maybe 3 problems. The rear flexi pipe was blocked, root cause of problem. Changed the pipe, flexi and slave just in case. Attempting to bleed the air out clearly damaged the MC. Changing the MC allowed more air in front and rear which 'mechanic' managed to remove enough to pass MOT after changing the rear shoes. The 'trapped' air was in the front not the rear. Quote Link to post Share on other sites
Guest ntc Posted April 17, 2016 Report Share Posted April 17, 2016 Your the doc you know best Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.