Tr4aJim Posted December 21, 2018 Report Share Posted December 21, 2018 Folks, Are these the Tr4a handbrake lever extensions I’ve seen mentioned on this forum? https://www.ebay.co.uk/itm/Triumph-Stag-TR4a-TR5-TR6-2000-2500-hand-brake-improver/372536247158?hash=item56bce40376:g:9boAAOSwHMJYEKBA thanks Jim Quote Link to post Share on other sites
peejay4A Posted December 21, 2018 Report Share Posted December 21, 2018 They’re the ones I have Jim. Quote Link to post Share on other sites
Tr4aJim Posted December 21, 2018 Author Report Share Posted December 21, 2018 Great, thanks! Jim Quote Link to post Share on other sites
AndrewMAshton Posted December 21, 2018 Report Share Posted December 21, 2018 These extensions increased my brake efficiency from 16% (15% is an MOT fail) to 25%, well worth fitting, cheers, Andrew Quote Link to post Share on other sites
Z320 Posted December 22, 2018 Report Share Posted December 22, 2018 (edited) A different idea on "Handbraake!" The lenght of the leavers is not the problem. Edited December 22, 2018 by Z320 Quote Link to post Share on other sites
Tr4aJim Posted December 22, 2018 Author Report Share Posted December 22, 2018 I wonder if the handbrake issue affects IRS cars differently than live axle cars. As I recall, the design of the handbrake cable mechanism was changed with the introduction of the Tr4a/IRS. However my TR4a has a live axle, so the handbrake action may feel slightly different than on an IRS car. Anyway, the reason for my sudden interest is, last month my wife and I went out for a drive to enjoy the last of the nice (above freezing) weather. As we were going along we hit a pothole which gave the car a pretty good shake. Suddenly we heard a loud rapid metallic clicking! I spotted a safe place to pull over to investigate, applied the brakes to slow down, and NO BRAKES! I was able to use the handbrake to slow down and stop without incident, however I wasn’t thrilled with the variation of force I could apply. Hopefully these extensions will provide a little more “bite”. BTW - the brake failure was caused by the front/to/rear brake line being struck by the rear universal joint of the driveshaft. Apparently the jolt from the pothole caused the line to move enough for the joint to hit it, bending it enough to keep striking it, causing that loud clicking noise. When I replaced the line, I added two more line clips along the frame, to keep the line nice and secure. Jim Quote Link to post Share on other sites
stuart Posted December 22, 2018 Report Share Posted December 22, 2018 FWIW The handbrake on a NON IRS 4A is the same as an IRS car so a lot less mechanically advantageous than a 4. I have a good handbrake on my solid axle 4a as I changed to 10" Alfin drums on the rear. Stuart. Quote Link to post Share on other sites
Tr4aJim Posted December 22, 2018 Author Report Share Posted December 22, 2018 Good to know, thanks Stuart! Jim Quote Link to post Share on other sites
Z320 Posted December 22, 2018 Report Share Posted December 22, 2018 Hi Jim, does your brake line go the wrong way? If the universal joint damaged it, and you only fixed the tube, the universal joint will damage it again, if you did not change the way. Drum brakes are "self forcing" (don't know if this is the correct english term). Therefore the brake shoe must fit as good as possible to the drum's diameter. New standard shoes on antique drums do not work good. Anyway the mechanism of the handbrake on TRs is a very, very sad construction. Ciao Marco Quote Link to post Share on other sites
Tr4aJim Posted December 23, 2018 Author Report Share Posted December 23, 2018 Hi Marco, When I replaced the damaged line, I tried unsuccessfully to find an “official” routing path or attachment points for the rear section of the two piece front to rear line. There were two pipe clips on the frame, about 18 inches or so on either side of the union joining those two pieces, roughly in line with the left seat. However looking toward the rear of the car, I did not see any other clips or other attachment points until the pipe union bracket by the left rear wheel (where it connects to the flex hose). So quite a bit of that rear pipe was unsupported. So I added an additional clip to the frame about two feet before the U-joint, which was the best I could do with the exhaust in place. I added another clip to the vertical sheet metal right after the pipe makes a 90 degree turn toward the left rear wheel. Now that pipe seems quite rigid and is well clear of the driveshaft. Cheers Jim Quote Link to post Share on other sites
qkingston Posted December 23, 2018 Report Share Posted December 23, 2018 Does anyone else sell these other than Tony Hart? Quote Link to post Share on other sites
keith1948 Posted December 23, 2018 Report Share Posted December 23, 2018 (edited) Not attached a file before but hope this has worked. This is (hopefully) something I wrote a while ago for a TR friend who was having trouble with his handbrake. It is the handbrake mod on my 4A which works very well. Still haven't got around to fitting the lever extensions. It goes into how I set up the rear brake cables so it now sails through the MOT (and more importantly holds the car on steep hills) Keith Mmmm seems you might have to log in as a member to see attachment. Maybe someone can try this to see if they can open it. Not sure what I've done wrong but as I say - first time doing this. Just tried dragging word file across to see if that works. Ok that didn't work either so now trying it as a pdf file. Aaargh no luck with that either. Says I don't have permission to upload file either .doc or .pdf - Any ideas anyone? At last success but you need to log in to see it. Improving TR4A.doc Edited February 4, 2020 by keith1948 reloaded pdf as word document Quote Link to post Share on other sites
stillp Posted December 24, 2018 Report Share Posted December 24, 2018 PDF was OK for me. Pete Quote Link to post Share on other sites
Tr4aJim Posted December 24, 2018 Author Report Share Posted December 24, 2018 Thanks Keith! Jim Quote Link to post Share on other sites
stuart Posted December 24, 2018 Report Share Posted December 24, 2018 Another point of interest to improve the handbrake action is to check the back plates where the handbrake lever mounting pins sit as by now a lot of them will have worn a grove in the back plate and if this is the case no matter how much you lube the brake cylinder in its slot in the back plate once you fit all the clips to hold it in this groove will hold the cylinder in one place so defeating the object as it will only move one shoe instead of both when you pull on the handbrake. Its an easy fix by welding up the grooves and carefully grinding the area flat again. This will give you full slide of the cylinder. Stuart. Quote Link to post Share on other sites
keith1948 Posted December 24, 2018 Report Share Posted December 24, 2018 (edited) Seems as if you can open the attachment if you sign in but doesn't open as a guest (i.e not signed in). Thanks Stuart for extra info. I'll look for the groove in the backplate when I get around to fitting the lever extensions. Keith Edited February 3, 2020 by keith1948 Quote Link to post Share on other sites
Z320 Posted December 24, 2018 Report Share Posted December 24, 2018 (edited) Hi Stuart, on my TR4A there have not been grooves, because the handbrake never worked. When I've been told about the grooves, my idea was this: what force / power must have been wasted senceless to make these grooves, instead of using this force to hold the car with the handbrake? And what more force is wasted to make new grooves by using the extensions? Cheers Marco Edited December 24, 2018 by Z320 Quote Link to post Share on other sites
MikeF Posted December 26, 2018 Report Share Posted December 26, 2018 The small chassis cars (Herald Spitfire GT6 etc) have a central tunnel mounted handbrake. As far as I know they don't have problems, Anything we can learn from them? Mike Quote Link to post Share on other sites
PaulAnderson Posted December 26, 2018 Report Share Posted December 26, 2018 If you look at past posts you will find that much of this has been discussed before. From 2005 there was and in 2010 there was this The suggestion then was these extension pieces could be self made as documented complete with dimensions in the Roger Williams book "How To Improve 2-4A" . Paul Quote Link to post Share on other sites
RogerH Posted December 26, 2018 Report Share Posted December 26, 2018 Hi Paul, very easy to make from 1" angler iron. Cut to length. Trim one flange down to to apprx 1/4" to lock against existing lever. Drill a hole in the 1" flange to align with existing hole in lever. and lock down with a nut/bolt. Drill new hole in angle iron apprx 1" from existing hole to take the cable clip. Job done Roger Quote Link to post Share on other sites
Z320 Posted December 26, 2018 Report Share Posted December 26, 2018 Still got these pair of brake plates in my workshop to do an essential modification. Hope this will happen soon, my plan is 2 or 3 years, one project after the other ... Cheers, Marco Quote Link to post Share on other sites
keith1948 Posted December 26, 2018 Report Share Posted December 26, 2018 (edited) Hello Roger - Merry Christmas If only the job was that simple. Had several discussions with Phil Barnett on the design of the extension lever. The lever pivots on an arc on the pin in the backplate. The end of the brake cable also pivots on an arc from the fixing point on the trailing arm. Any extension of the lever arm needs to take this into consideration so that the extended lever can simply be connected to the end of the brake cable without any adjustment to the length of the cable. The mark 1 version simply extended the length of the lever which required quite a bit of adjustment (lengthening) of the cable. The mark 2 design was a slightly cranked lever which didn't need any adjustment. Here are a couple of diagrams I did at the time that hopefully explains it all. Hope you can open the pdf files. Keith img003.pdf img004.pdf Edited December 26, 2018 by keith1948 typo Quote Link to post Share on other sites
RogerH Posted December 26, 2018 Report Share Posted December 26, 2018 Hi Keith, I'm sure there is a theoretical [perfect design. I just made mine (10 or more years ago), extended the cable adjuster to align the holes and off I went. The obvious problem with these or any extension is that what you gain at one end you lose at the other. Therefore so as to avoid an over long handbrake one needs to have brakes adjusted nicely. Roger Quote Link to post Share on other sites
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