Myles Posted June 12, 2005 Share Posted June 12, 2005 Swapped to a race MC this w/e - seems to have sorted things out somewhat. I now want to pull apart the std. MC to see if it has any clues to what was causing my earlier problems - and to refurb it for resale. I've removed the circlip and threaded rod - and that's as far as I've got - I can't see how the plungers etc. can be removed. Do I have to remove the reservoir??? Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Edited by - Myles on 12 Jun 2005 20:33:29 Edited by - Myles on 14 Jun 2005 08:18:16 Edited by - Myles on 14 Jun 2005 19:44:22 Link to comment Share on other sites More sharing options...
Bafty Crastard Posted June 12, 2005 Share Posted June 12, 2005 What's a MC The R300 NUT'errrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr Link to comment Share on other sites More sharing options...
alicat Posted June 12, 2005 Share Posted June 12, 2005 Master Cylinder Link to comment Share on other sites More sharing options...
Trevor Newman Posted June 12, 2005 Share Posted June 12, 2005 Motor Cycle? Master of Ceremonies? Link to comment Share on other sites More sharing options...
Bafty Crastard Posted June 12, 2005 Share Posted June 12, 2005 What's a Master Cylinder R300 NUT'errrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr Link to comment Share on other sites More sharing options...
Trevor Newman Posted June 12, 2005 Share Posted June 12, 2005 more important than a slave cylinder Link to comment Share on other sites More sharing options...
Myles Posted June 12, 2005 Author Share Posted June 12, 2005 Come-awn! It's da big pumpy thing that makes all the goodness rush to the clappers to create lots of white smoke and full underpants. But seriously - howja get the damned-thing apart... Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
Myles Posted June 13, 2005 Author Share Posted June 13, 2005 Bingaley-boing Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
Myles Posted June 14, 2005 Author Share Posted June 14, 2005 Now with new title for added kaboing Surely someone must know... Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
JampJ Posted June 14, 2005 Share Posted June 14, 2005 Remove the rubber cap, you will then see a circlip with a hole at each end. Close them together to release the clip. All the inards should then come out. Be careful as they may spring out!! Take careful note of the order and direction of all the items, for replacement. It would be useful to know what model car it originates from for the purpose of getting seals. Cheers J&J Edited by - johnjulie on 14 Jun 2005 08:29:46 Edited by - johnjulie on 14 Jun 2005 08:30:54 Link to comment Share on other sites More sharing options...
Myles Posted June 14, 2005 Author Share Posted June 14, 2005 Thanks - but it hasn't worked like that... I removed the circlip, and this allowed the actuator-shaft to fall away - but the pistons etc. do not come out - they seem to sit against the end of the cylinder. I've tried pushing them in to see what happens - but they just come to rest against the end of the cylinder again. I probably ought to take some pics this PM if no-one can spot my obvious mistake... Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
JampJ Posted June 14, 2005 Share Posted June 14, 2005 Myles, if you remove the fluid container, then look down the holes, you may see a pin sticking up in one of them! If there is, try pushing it down, this should release the inards. That's why it would be useful to know the cylinders origins so the details could be looked up in a manual. Cheers J&J Link to comment Share on other sites More sharing options...
Myles Posted June 14, 2005 Author Share Posted June 14, 2005 Thanks - I'll give it a go. Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
Nigel Riches Posted June 14, 2005 Share Posted June 14, 2005 Do you have a wire terminal at about the middle of the cylinder length? This, if you have one, is to warn of lack of pressure in one of the cylinders, brings on a warning light on the dashboard, you will need to unscrew this contact, as it's positioned in an undercut section of the actuator shaft. The innards should then come out, and as has been mentioned there may well be a spring, so beware of where the bits fly off too. 1982. 5 speed, clamshells. B.R.G / Ali. The True Colours. Link to comment Share on other sites More sharing options...
susser Posted June 14, 2005 Share Posted June 14, 2005 If that pin of johnjulie's doesn't push down it will probably pull out. It's a backup to prevent the piston clearing the barrel. Sits in the hole revealed by removing the resovoir. PS Push the piston in to take the weight off the pin. There are 2 springs trying to eject the pistons in a dual circuit cylinder, only one in a single circuit. Edited by - susser on 14 Jun 2005 10:15:41 Link to comment Share on other sites More sharing options...
Myles Posted June 14, 2005 Author Share Posted June 14, 2005 Thanks. Nigel - no contact - this is the 'standard' CC MC... Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
JampJ Posted June 14, 2005 Share Posted June 14, 2005 Quite right Susser, it should pull out, not push in. Easy thing to lose too! Do you know what car they are off? Cheers J&J Link to comment Share on other sites More sharing options...
Myles Posted June 14, 2005 Author Share Posted June 14, 2005 Right, managed it tonight. The the reservoir fits into a chunky rubber-seal for the secondary-circuit - nothing like it on the primary circuit. Once you've got the seal out of the way, you can pull the small pin out -and this releases the pistons. The rear piston was reluctant to come out - but I just tapped the cylinder against a wall until it moved down the bore. Now - I can't see anything wrong with the seals - they look fine... There is some polishing on certain parts of the primary-plunger - but this is to be expected as the actuator-rod doesn't push directly along the axis of the bore when the pedal is actuated. I tried to measure for out-of-round, but it really is just polishing - no measurable wear. It's possible that there was some crud in there that was stopping the seals from working perfectly - but I can't see the evidence. I wonder if there is anyone who can examine it and pronounce whether there was an MC issue or not... Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
susser Posted June 14, 2005 Share Posted June 14, 2005 Sometimes the wear is on the seal rather than the bore. They are designed to expand against the bore as pressure increases. Occasionally one will leak a bit when standing, but you can stand on the pedal all day without it moving. If you look at the edge of the seal (the sharp bit) you may see it has been flattened. That will be the problem. If that's the case, then a new seal or pair of seals will make it perfectly serviceable. Link to comment Share on other sites More sharing options...
Myles Posted June 14, 2005 Author Share Posted June 14, 2005 The problem was not a static-leak - the cylinder was fluid-tight. The problem was that you could put pressure on the pedal, and it would build up a reasonable firmness - but it could/would then sloooowly sink, but with quite a lot of force required. The other symptom was that the front-braking effort seemed poor and the brake-balance was biased to the rear. The suspicion was that there might have been a problem with the primary-circuit seals. I haven't done more than a few-dozen miles with the brand-new uprated MC, but the bias seems to be back to the front of the car. I like the reduced pedal-travel - so even if the MC was not the problem, I've made a step forward... THe other, obvious, possibility is a leak in the front circuit - but I've not been able to find one. I did (immediately after fitting new 4-pots and hoses) have a teething-leak where the flexis join the hardlines (you could wipe your finger under the union and find a trace of fluid) - but repeated tightening of these unions seems to have done the trick - I can't find any fluid. If there was a leak - it'll still be there - I've not touched anything other than the MC. I've not noticed a problem with the uprated MC sinking - but then; i) it's pumping a larger volume of fluid - so a small leak would take longer to let the pedal sink (OK, it's at a higher pressure but...( ii) the rear circuit (assumed good) would prevent pedal-movement quite quickly. The only slight-niggle I have with the brakes at the moment (still bedding in new Pagids at the front) is a very slight pull to the right when the pads really start to bite - but this could be due to bedding-in/whatever (the OSF tends to lock first too - but this seems to be a reasonably-common problem - possibly road-camber related). Sooo - there you go - if anyone has any comments, please feel free.. Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
susser Posted June 14, 2005 Share Posted June 14, 2005 Pagid Those pads I said were Jurids were Pagids (See scary BMW,,,,,,,,) Pagids were £18+ from ECP, BMW Gen items £29. No contest. Even to a poor person. Mind you there's pads and there are pads. I'm not up on materials. PS Got some biiiiiiiiiiiig smoke off my OSF tonight at 60, even though it's weighted a bit, looking at the shox. Edited by - susser on 14 Jun 2005 20:38:58 Link to comment Share on other sites More sharing options...
JampJ Posted June 14, 2005 Share Posted June 14, 2005 Myles, it's usually the seals that go hard, and shrink slightly, not enough to show a leak always, but enough to stop them functioning correctly. Keep us informed if you relace them. Cheers J&J Link to comment Share on other sites More sharing options...
Myles Posted June 14, 2005 Author Share Posted June 14, 2005 Susser - the Pagids you'll see mentioned on BC are from the race-pad range... Almost universally accepted as being just about the best (and most expensive) pads for 7s... At £100+VAT for one axle-set, I suspect the £18 beemer jobs are from a lesser road-range... Having said that - I was a bit disappointed with the amount of work I need to apply before I could fit them - the backing-pads needed a load of swarf etc. filing off before they would slide into the clappers smoothly - the holes through which the retaining pins fit were similarly messy. No big deal - and race pads are for go - not show (IYSWIM ), but still... J&J - I'll take another look, but I'm not planning to refit the old MC myself - I'll order a seal-set and refurb them and see if the seal material feels/looks different. This MC has done 22k miles over 4 years - the first year (or so) and 4-5k miles was Academy/grads racing, so they've worked reasonably hard. Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
susser Posted June 14, 2005 Share Posted June 14, 2005 Guess they made my cheapie pads outta the box the race ones came in. Link to comment Share on other sites More sharing options...
elie boone Posted June 15, 2005 Share Posted June 15, 2005 Myles, Bleeding brake by pumping the pedal is never good for your mc seals especially when they are past their best. When there is no sign of brake fluid loss its because the fluid returns to the reservoir. Link to comment Share on other sites More sharing options...
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