Richardtr3a Posted August 14, 2010 Report Share Posted August 14, 2010 My brake pedal on my 3A is gradually getting harder and harder. The brakes work well and we just passed the MOT, so they are loosening off well. I am tempted to check inside the master cylinder where I think there is a return port internally. Does anuone have an intimate knowledge of the workings of the master cylinder. If the pads were not retracting I would hear a noise and the MOT man would be on to it. Has any one else had such a problem? Quote Link to post Share on other sites
TomMull Posted August 14, 2010 Report Share Posted August 14, 2010 My brake pedal on my 3A is gradually getting harder and harder. The brakes work well and we just passed the MOT, so they are loosening off well. I am tempted to check inside the master cylinder where I think there is a return port internally. Does anuone have an intimate knowledge of the workings of the master cylinder. If the pads were not retracting I would hear a noise and the MOT man would be on to it. Has any one else had such a problem? I had similar issue years ago on my 3A. A master cylinder kit fixed it. However, several things could cause the hard pedal. I would lift the car and re-confirm that all four wheels are braking and releasing. Tom Mulligan Quote Link to post Share on other sites
ianc Posted August 14, 2010 Report Share Posted August 14, 2010 Back in the 1960s, on my disc-braked TR2, I suffered from retained pressure in the brake system and this caused the discs to get very hot - and reduced top speed! The quick fix was to release the bleed nipple on one calliper, but, as I considered brakes rather critical to life expectancy, the proper fix was to swap the master cylinder (it was the combined brake/clutch type). In your case, it could be the pressure retaining valve (116197, called the restrictor valve, situated on top of the 5-way coneector), retaining too much pressure. I suggest you do what many of us have done - dismantle this valve, remove its innards, then replace it as a straight-through tube (this avoids the need to fit a longer bundy between master cylinder and 5-way connector). Ian Cornish Quote Link to post Share on other sites
TomMull Posted August 14, 2010 Report Share Posted August 14, 2010 Back in the 1960s, on my disc-braked TR2, I suffered from retained pressure in the brake system and this caused the discs to get very hot - and reduced top speed! The quick fix was to release the bleed nipple on one calliper, but, as I considered brakes rather critical to life expectancy, the proper fix was to swap the master cylinder (it was the combined brake/clutch type). In your case, it could be the pressure retaining valve (116197, called the restrictor valve, situated on top of the 5-way coneector), retaining too much pressure. I suggest you do what many of us have done - dismantle this valve, remove its innards, then replace it as a straight-through tube (this avoids the need to fit a longer bundy between master cylinder and 5-way connector). Ian Cornish Ian, I think Standard Triumph discontinued this restrictor valve some time before the TR3A came out, but if it's there, I agree it would be good to take it out. Tom Quote Link to post Share on other sites
vivdownunder Posted August 15, 2010 Report Share Posted August 15, 2010 Tom, I think you'll find the restrictor valve was phased out during TR4A production. Richard, the main rubber (pressure) cup in the master cylinder can soften over time and tend to grab. A repair kit is one answer, but the M/C should also be re-sleeved. For the small extra cost, when a M/C falters I always fit a brand new one. Having suffered one total brake failure with a rebuilt M/C, I'd never knowingly risk a second episode. Regards, Viv. Quote Link to post Share on other sites
stuart Posted August 15, 2010 Report Share Posted August 15, 2010 Always replace with new. Its brakes after all!. Re-rubbering is very seldom successful. Stuart. Quote Link to post Share on other sites
TomMull Posted August 15, 2010 Report Share Posted August 15, 2010 Tom, I think you'll find the restrictor valve was phased out during TR4A production. Richard, the main rubber (pressure) cup in the master cylinder can soften over time and tend to grab. A repair kit is one answer, but the M/C should also be re-sleeved. For the small extra cost, when a M/C falters I always fit a brand new one. Having suffered one total brake failure with a rebuilt M/C, I'd never knowingly risk a second episode. Regards, Viv. Viv, You and Ian are, of course, correct. I should have known that Ian would have it right. Good advice on the new cylinder too. Tom Quote Link to post Share on other sites
Richardtr3a Posted August 16, 2010 Author Report Share Posted August 16, 2010 Back in the 1960s, on my disc-braked TR2, I suffered from retained pressure in the brake system and this caused the discs to get very hot - and reduced top speed! The quick fix was to release the bleed nipple on one calliper, but, as I considered brakes rather critical to life expectancy, the proper fix was to swap the master cylinder (it was the combined brake/clutch type). In your case, it could be the pressure retaining valve (116197, called the restrictor valve, situated on top of the 5-way coneector), retaining too much pressure. I suggest you do what many of us have done - dismantle this valve, remove its innards, then replace it as a straight-through tube (this avoids the need to fit a longer bundy between master cylinder and 5-way connector). Ian Cornish Quote Link to post Share on other sites
Richardtr3a Posted August 16, 2010 Author Report Share Posted August 16, 2010 My restrictor valve was removed by the Standard Triumph agent in Brighton, Moores, in 1967. But I seem to remember that there is some small port which allows the fluid to return inside the master cylinder. I have a new cylinder so that looks like a job for next week end. Thanks Richard 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.