badshead Posted October 19, 2010 Report Share Posted October 19, 2010 I've noticed my brakes are getting slowly, but progressively worse e.g. increasing pedal travel but improve when pumped. A good bleed hasn't improved things so I'm thinking maybe the master cylinder is ready for a change? First stab of the pedal = quite long travel and there's the sensation of the pedal slowly sinking (but not all the way) if you maintain pressure. However, a few pumps will shorten travel and less of a sinking sensation if pedal continues to be applied. A search of previous posts seems to favour replacement cylinder rather than service kit. Given it's a singe circuit system I'd appreciate any recommendations for good quality, tried & tested replacement. Prices from the usual suspects vary widely from £60 to £120+ Quote Link to post Share on other sites
RogerH Posted October 19, 2010 Report Share Posted October 19, 2010 Hi Bill, check your front wheel bearings first, you may be experiencing pad knock back. Roger Quote Link to post Share on other sites
Jersey Royal Posted October 19, 2010 Report Share Posted October 19, 2010 Bill, Also consider checking run out on discs with dial gauge. Cheers Guy Quote Link to post Share on other sites
Herald948 Posted October 19, 2010 Report Share Posted October 19, 2010 Have you checked rear brake adjustment? Quote Link to post Share on other sites
badshead Posted October 20, 2010 Author Report Share Posted October 20, 2010 Thanks for the responses Guy/Roger, Bearing adjustment is ok and pedal travel/symptoms also evident when stationary so I'm assuming that rules out pad/disk cause? Andy, Have just rechecked and notice that I can't lock the n/s rear wheel with the adjuster (other side ok). Worked fine last time I used it - will investigate. Out of interest, do others have the same problems as me with these one-man bleed kits on the market? A while ago I tried the type where you lightly pressurise the system using an old tyre - result was overfilled master cylinder and brake fluid everywhere . Yesterday I tried the version where you use the vacuum created by compressed air to suck the fluid out - result was fizzy brake fluid being expelled as the vacuum also draws air in around the connection to the bleed nipple! Also, noticed in the Workshop Manual (3.203) that "clutch and brake master cylinders cannot be removed individually, but only as an assembly", that's surely wrong as it looks like the brake master will come out easily without disturbing the clutch master? Quote Link to post Share on other sites
stuart Posted October 20, 2010 Report Share Posted October 20, 2010 Also, noticed in the Workshop Manual (3.203) that "clutch and brake master cylinders cannot be removed individually, but only as an assembly", that's surely wrong as it looks like the brake master will come out easily without disturbing the clutch master? Problem being the push rod. You could get it out if you remove the circlip that holds the push rod in but you then run the risk of fluid every where from in the cylinder. Also you would need to rotate the master around a lot to fiddle it out due to the quadrant of the rain channel where the bonnet stop is. If you remove the clips holding the pipes across the bulkhead then you can unbolt and lift the whole mounting bracket up enough (provided you have copper pipes not original steels ) so you dont have to disconnect the clutch pipe. Obviously drain brake master, remove clevis and remove pipe and plug pipe line and remove the two mounting bolts from the master first before lifting. I have always bled my brakes/clutches by using the old rubber pipe into a glass jar method, no extra air introduced that way. Stuart. Quote Link to post Share on other sites
badshead Posted October 20, 2010 Author Report Share Posted October 20, 2010 Many thanks Stuart. I'm still on steel pipes so looks like both will be coming off.. not a big deal really just wanted to avoid if I could. Would you suspect the master given the symptoms I describe? Do you have a favourite suppier for brake items? Quote Link to post Share on other sites
stuart Posted October 20, 2010 Report Share Posted October 20, 2010 Many thanks Stuart. I'm still on steel pipes so looks like both will be coming off.. not a big deal really just wanted to avoid if I could. Would you suspect the master given the symptoms I describe? Do you have a favourite suppier for brake items? If the pedal is going away from you under pressure and there are no leaks in the system then yes. Past parts are good for brake parts. Past Parts. Stuart. Quote Link to post Share on other sites
Ade-TR4 Posted October 20, 2010 Report Share Posted October 20, 2010 I've found that bleeding the brakes is a 2 person job, with the already described pipe in jam-jar method. I too have only managed to spill (expensive) brake fluid all over the place using the one-man systems. btw, rear brake adjustment does affect the brake pedal travel more than you'd expect. Cheers Adey Quote Link to post Share on other sites
67_gt6 Posted October 20, 2010 Report Share Posted October 20, 2010 (edited) I have done one man bleeding with a piece of wood to jam the pedal down using underside of steering wheel on final bleed strokes. Pump the pedal a few times while adding to M/C if necessary, jam pedal down with wood, examine the see through tubing to confirm that the last inch of fluid to come out was "solid", tighten up nipple. Perhaps best if you are using standard fluid which is cheap enough if you end up using a fair bit of it. Leave piece of wood jammed overnight to confirm success. Andy Edited October 20, 2010 by 67_gt6 Quote Link to post Share on other sites
Herald948 Posted October 20, 2010 Report Share Posted October 20, 2010 (edited) Andy,Have just rechecked and notice that I can't lock the n/s rear wheel with the adjuster (other side ok). Worked fine last time I used it - will investigate. I'll be interested in hearing about what you find, but I suspect you may have located at least part of the problem. At the moment, my Herald's brake system is behaving pretty much exactly as you describe. Being an all-drum-braked car, there are SIX adjusters (four in front, two in back), and I'm pretty sure it's time to check all SIX of them! Oh, and I'm with Andy (great name!) on the one-man bleeding with a block of wood, etc. Been doing that for years, as I've long since run out of willing assistants, now that my son and daughter are grown and almost never around (and the ex- really never did like to help on such jobs)! Edited October 20, 2010 by Herald948 Quote Link to post Share on other sites
Jersey Royal Posted October 20, 2010 Report Share Posted October 20, 2010 Had one of my rear brake adjuster go. Same story as yours, was the thread on the adjuster, i removed the adjuster and could push the threaded bolt back and forth. Cheers Guy Quote Link to post Share on other sites
MadMarx Posted October 23, 2010 Report Share Posted October 23, 2010 Had one of my rear brake adjuster go. Same story as yours, was the thread on the adjuster, i removed the adjuster and could push the threaded bolt back and forth. from which manufacturer came the adjuster? Quote Link to post Share on other sites
Jersey Royal Posted October 23, 2010 Report Share Posted October 23, 2010 from which manufacturer came the adjuster? Hi Chris, Sorry i cant recall, must have been ten years old though. Got a repalcement from Revington, all ok. Cheers Guy Quote Link to post Share on other sites
Herald948 Posted October 24, 2010 Report Share Posted October 24, 2010 from which manufacturer came the adjuster? Fair question, Chris. I've heard some less-than-favorable reports about some repro adjusters. On the other hand, I've saved literally dozens of frozen original Girling adjusters with no more than a couple minutes with a propane torch to free the rust bonds, followed by some cleanup and reassembly with white lithium grease! I honestly haven't lost one yet since I figured out that the above, rather than using a pipe wrench with a 10ft extension to try to free them up, was the way to go. Quote Link to post Share on other sites
harrytr5 Posted October 28, 2010 Report Share Posted October 28, 2010 Whilst piloting a friends TR4/6 from Ally Pally to his house the brakes failed going down Muswell Hill and I had to use the fly off handbrake(very differcult when it is the upright against the gearbox tunnel , TR4)To say I was nearly cr*pping myself was an understatement.I managed to drive to his home with some near misses despite trying to pump some life into the brakes.Deduced it was the brake master cylinder.Changed it and all is well.This is a non servo braked TR4.Jesus had nightmares for a few nights after that!. I use a non return one man brake bleeder.Have tried all others and this is the one that works for me. Regards Harry TR5 Nutter Quote Link to post Share on other sites
ianhoward Posted October 28, 2010 Report Share Posted October 28, 2010 For Brake Bleeding I got one of these from my local Motorshop... Vizibleed Easy to use - by yourself and only £3.00!!! Cheers Quote Link to post Share on other sites
badshead Posted November 3, 2010 Author Report Share Posted November 3, 2010 Just to conclude this one.... rebuilt the master cylinder, sorted out the seized rear brake adjuster and bled/flushed the whole system using the old fashioned jam jar & spare family member method. Result is good brakes, so much so I've abandoned long standing plans for a servo as they're fine without one. Quote Link to post Share on other sites
Herald948 Posted November 3, 2010 Report Share Posted November 3, 2010 Congratulations, Bill; well done! Quote Link to post Share on other sites
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