timreid Posted April 13, 2016 Report Share Posted April 13, 2016 We have been having problems with the brakes and have diagnosed the problem as the brake restrictor valve. Having spoken to a few people most suggested that we just do without it. This doesn't seem ideal and I wondered if it had been put together correctly as the screw part could easily be reversed. Photo attached, can anyone confirm if this is the correct alignment for all the parts? Many thanks yours Tim Quote Link to post Share on other sites
Fireman049 Posted April 13, 2016 Report Share Posted April 13, 2016 Hi Tim ~ On advice from other Forum members I removed the restrictor valve from my 3A with no ill effects. Tom. Quote Link to post Share on other sites
iain Posted April 13, 2016 Report Share Posted April 13, 2016 Educate me please ....what does this do? Am I right in assuming it is on the MC outlet? Thanks Iain Quote Link to post Share on other sites
Lebro Posted April 13, 2016 Report Share Posted April 13, 2016 It goes in the line to the rear brakes only. It's to (supposedly) prevent rear brake lockup. Bob. Quote Link to post Share on other sites
iain Posted April 13, 2016 Report Share Posted April 13, 2016 (edited) Thanks Bob.....and where would it usually be located?......I might just have left that off 35 years ago..unwittingly :-) Edited April 13, 2016 by iain Quote Link to post Share on other sites
Drewmotty Posted April 13, 2016 Report Share Posted April 13, 2016 It goes between the master cylinder and the rest of the braking system and sits on the multi way manifold on the chassis rail just behind the offside turret. The theory is that it maintains a very low pressure in the system to keep the pads in light contact with the discs. Practice showed that it made the brakes drag and wasn't required so it was deleted from later models. I've taken the spring and poppet out of mine. Quote Link to post Share on other sites
iain Posted April 13, 2016 Report Share Posted April 13, 2016 Cheers Andrew. It might still be there then! Is it on the feed to the rear line off the 4 way junction? Iain Quote Link to post Share on other sites
Drewmotty Posted April 13, 2016 Report Share Posted April 13, 2016 It is in the line from the master cylinder and screws into the top port of the small manifold which also takes the brake light pressure switch. Quote Link to post Share on other sites
Guest ntc Posted April 13, 2016 Report Share Posted April 13, 2016 It goes in the line to the rear brakes only. It's to (supposedly) prevent rear brake lockup. Bob. Correct and for use with 10 inch rear drums Quote Link to post Share on other sites
iain Posted April 13, 2016 Report Share Posted April 13, 2016 Thanks Chaps its there, and I have a very early 3A with 10" rear brakes. Whether the guts are still in the valve I will check. Currently a dry system so no issue to have a look! What is the current consensus wrt keeping the valve in an operational state? Quote Link to post Share on other sites
Drewmotty Posted April 13, 2016 Report Share Posted April 13, 2016 That's not where Triumph fitted it. http://www.moss-europe.co.uk/shop-by-model/triumph/tr2-4a/brake-system/brake-controls-hydraulics/brake-pipes-girling-system.html .....and if they had it wouldn't have restricted the pressure as it actually restricts the return. Just to check that I'm not in the wrong profession I've done a quick forum search and found that there has been plenty of discussion on this before. Quote Link to post Share on other sites
Richardtr3a Posted April 13, 2016 Report Share Posted April 13, 2016 This valve was always a mistake. A long time ago I had a brake problem. In those days we still had main agents and used them. My local ST agent, Moores of Brighton, removed the valve and I still have the invoice. Remove wheels Check calipers New front brake pipe Remove hydraulic restrictor New hose 115459 Total £3.18.10 dated 30.10.1967 Those were the days. Quote Link to post Share on other sites
Guest ntc Posted April 13, 2016 Report Share Posted April 13, 2016 Thanks Chaps its there, and I have a very early 3A with 10" rear brakes. Whether the guts are still in the valve I will check. Currently a dry system so no issue to have a look! What is the current consensus wrt keeping the valve in an operational state? With 10 inch yes you will find out in bad road conditions when you hit the brake pedal . Quote Link to post Share on other sites
Don Elliott Posted April 14, 2016 Report Share Posted April 14, 2016 Here is a sketch I did in 1990. It is still in use in my 1958 TR3A and has never caused any issues. Quote Link to post Share on other sites
iain Posted April 14, 2016 Report Share Posted April 14, 2016 (edited) Just checked and the restrictor is still in place, whether its has the guts I will establish this evening As always many thanks. This valve was always a mistake. A long time ago I had a brake problem. In those days we still had main agents and used them. My local ST agent, Moores of Brighton, removed the valve and I still have the invoice. Remove wheels Check calipers New front brake pipe Remove hydraulic restrictor New hose 115459 Total £3.18.10 dated 30.10.1967 Those were the days. Sounds cheap, about £110 in today's money? Edited April 14, 2016 by iain Quote Link to post Share on other sites
Lebro Posted April 14, 2016 Report Share Posted April 14, 2016 Looks like I was wrong to say that it goes in the rear brake line only. This is often done on other old cars, but perhaps not in this case. Sorry for any misinformation. Bob. Quote Link to post Share on other sites
Alec Pringle Posted April 14, 2016 Report Share Posted April 14, 2016 The restrictor valve was fitted between the master cylinder and the multiway connector, and intended to maintain a low residual pressure in the hydraulic system to ensure that the front brake pads did not withdraw too far and thus leave a 'long pedal'. Early days of disc brakes, remember, Triumph were pioneers . . . . . Good theory, and it did work initially, but the valve wasn't really necessary and tended not to work correctly for very long - brake fluid not changed regularly, resulting corrosion prevented the valve from working properly. Subsequent owners often refitted the valve incorrectly on rebuild, assuming that it was intended to act on the rear brakes - understandable, neither the TR2/3 workshop manual nor the parts book as printed clarified the fitment adequately. Only those lucky enough to have an ex-dealer book with supplementary service notes would have had a clear understanding. Available from aftermarket suppliers in period was a very different sort of restrictor valve intended to help prevent rear brake lock-up, and fitted between the same multiway connector and the rear brakes - this was not, as far as I'm aware, ever a factory fitment. Cheers Alec Quote Link to post Share on other sites
iain Posted April 14, 2016 Report Share Posted April 14, 2016 The value of the forum is that we can discuss these issues and get the correct answer. Many heads and all that ... Will take the restrictor out later and see whats in it..........the suspense I know is killing you! Quote Link to post Share on other sites
iain Posted April 15, 2016 Report Share Posted April 15, 2016 Well. Taken apart and low and behold,some minor grime but all the bits there and perfectly serviceable.No rust all very clean when the old bf was washed off. So these bits have been there for 36 years plus with no attention.....must have been lucky I guess. Question is do I reassemble and see what happens or is the perceived wisdom to leave the guts out and then see what happens? Quote Link to post Share on other sites
Richardtr3a Posted April 15, 2016 Report Share Posted April 15, 2016 If Standard Triumph agents were instructed to remove them the answer must be to remove. My brakes are the least of my recurring problems over the years. I have had no pressure troubles since mine was removed. It has been a long test so we must assume that it is better without. Nowadays there would be a factory recall. Good luck, Richard & H. Quote Link to post Share on other sites
foster461 Posted April 16, 2016 Report Share Posted April 16, 2016 We have been having problems with the brakes and have diagnosed the problem as the brake restrictor valve. Having spoken to a few people most suggested that we just do without it. This doesn't seem ideal and I wondered if it had been put together correctly as the screw part could easily be reversed. Photo attached, can anyone confirm if this is the correct alignment for all the parts? Brake restrictor valve.JPG Many thanks yours Tim I think your plunger is the wrong way around and your picture doesnt show the copper washers but really you should just gut it and re-fit. Here's how mine looked when dismantled. Quote Link to post Share on other sites
iain Posted April 16, 2016 Report Share Posted April 16, 2016 Now removed. Quote Link to post Share on other sites
timreid Posted April 18, 2016 Author Report Share Posted April 18, 2016 Thank-you all for your replies, all appreciated. Another fascinating piece of development. yours Tim Quote Link to post Share on other sites
foster461 Posted April 18, 2016 Report Share Posted April 18, 2016 I notice that some modern cars have devices built into the calipers to pull the pads away from the disc after braking as a fuel economy measure. Stan Quote Link to post Share on other sites
TomMull Posted April 18, 2016 Report Share Posted April 18, 2016 I notice that some modern cars have devices built into the calipers to pull the pads away from the disc after braking as a fuel economy measure. Stan Stan, This is not much of a problem with hydraulics on both sides of the disc as it is with the newer ones with hydraulics on one side and a mechanical connection on the other. Tom Quote Link to post Share on other sites
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