jp7 Posted April 29, 2002 Share Posted April 29, 2002 Hi all, just finished helping my brother put together his new Vauxhall Classic. He noticed that the brake pedal needs to be pushed down around 2" before the brakes start to bite. My Dedion needs only around 1". Is it a function of the brakes on the classic or have we done something wrong? Cheers Andy Link to comment Share on other sites More sharing options...
Graham Sewell Posted April 30, 2002 Share Posted April 30, 2002 Sounds like the brakes need re-bleeding. The rears can be a real pain as there is only the one bleed valve between the two wheels. Cheers, Graham Low tech luddite - xflow and proud! Link to comment Share on other sites More sharing options...
Super_Rich_Bernie Posted April 30, 2002 Share Posted April 30, 2002 Andy It might drop after the rear brake shoes have a few miles on them and are bedded in - then you can re-adjust them. (Are De Dions self adjusting? The Classic brakes are not.) The pedal travel on mine is pretty short. Either that or adjustment at the pedal to master cylinder end. Jonathan Link to comment Share on other sites More sharing options...
ashaughnessy Posted April 30, 2002 Share Posted April 30, 2002 On my live axle 1987 car with standard-for-that-time master cylinder, there is about an inch of travel before anything happens. I believe from earlier blatchat threads that this is normal. Other likely reasons for travel include: - You haven't adjusted the rear brakes correctly. I was taught to do this by tightening the rear adjusters until the wheel is solidly locked then backing off until the wheel turns freely. - The front pads are being knocked off the disks or are withdrawing. You can find that the pads withdraw back into the caliper when you release the brakes because of the pull of the rubber seals. You can see this if you take the wheel off and get someone to press the brake while you look at the movement of the pads. When they release the brake, do the pads move back into the pistons? A movement of just a millimetre or so at the pads translates to quite a lot of movement at the pedal. The answer here is to remove the pads and press out the pistons a bit further with the brake pedal (make sure you don't pop the pistons out of the caliper). Then press the pistons back into the caliper until there is *just* enough room to squeeze the pads back in very tightly. You should then hear the pads just lightly scraping against the disk when you spin the wheel, but the wheel should turn freely. Air in the system will give a different pedal feel to badly adjusted brakes. Can't describe it, though. Anthony Link to comment Share on other sites More sharing options...
jp7 Posted April 30, 2002 Author Share Posted April 30, 2002 Thanks for the replies, i shall try all these things at the weekend. Cheers Andy Link to comment Share on other sites More sharing options...
Fred Posted April 30, 2002 Share Posted April 30, 2002 the mistake most people make is not to slacken the hand brake cable of FIRST take the adjustment right of on the cable then adjust the drums then cable last. you can test this before you do anything pull on hand brake thenn press pedal if it is beter with the hand brake on then your prob is in the rear fredid=blue> biggrin.gif Link to comment Share on other sites More sharing options...
Paul Turner Posted April 30, 2002 Share Posted April 30, 2002 Andy I remember from having my Ital axle car the frustration of trying to get a good pedal but after many diff changes I discovered a simple routine (for my car). After working on the axle and bleeding the brakes the pedal was always low and a bit soft but re-bleeding made little or no difference, the brakes did work though. I then took the car out on short drive, only about 10 miles and then re-bleed brakes, the pedal would then return to its original height and feel. Never asked why but it always worked for me, it saved many a litre of wasted fluid for no pedal improvement. I always used a Gunsons pressure bleeding device (the one that uses a tyre as a pressure vessel). I second the comments re the handbrake and brake adjustment. Paul Link to comment Share on other sites More sharing options...
jp7 Posted April 30, 2002 Author Share Posted April 30, 2002 Cheers, i've just pushed the pedal with the handbrake pulled on a little bit and the pedal is a lot firmer, with not much travel. I suppose thats the problem. Are you saying that its best to disconnect the handbrake first, then bleed the brakes? Andy Link to comment Share on other sites More sharing options...
ashaughnessy Posted April 30, 2002 Share Posted April 30, 2002 I think the idea is to slacken the handbrake cable just before you do the rear brake adjustment. The handbrake cable slackening wouldn't make any difference to the bleeding. Anthony Link to comment Share on other sites More sharing options...
jp7 Posted April 30, 2002 Author Share Posted April 30, 2002 Many thanks thumbsup.gif Edited by - andy perry on 30 Apr 2002 16:08:24 Link to comment Share on other sites More sharing options...
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