John Morrison Posted April 27, 2021 Report Share Posted April 27, 2021 Hi all, I've seen this more than once, but cannot, now that I need the info, find it anywhere. I'm after the detail on re-drilling the 4A handbrake pawl, so as to increase the leverage, anyone got the info? Also whats a simple, hopefully in situ test for a 4A Temp Guage got one reading really high, when the engine is fine. Cheers, John. Quote Link to post Share on other sites
RogerH Posted April 27, 2021 Report Share Posted April 27, 2021 (edited) Hi John, the hole is quite limited in where it can go. Mid way between the existing hole and the curve of the metalwork. For the gauge - pop the temp sender into a pan of hot water on a fly lead for the earth. You will need a thermometer in the pan. Roger PS - you should not be drilling the pawl etc but the hole for the cable clip. Edited April 27, 2021 by RogerH Quote Link to post Share on other sites
jerrytr5 Posted April 27, 2021 Report Share Posted April 27, 2021 Jerry Quote Link to post Share on other sites
Lebro Posted April 27, 2021 Report Share Posted April 27, 2021 Re the temperature gauge reading high - check the voltage stabiliser is connected, & working. Does the fuel gauge read correctly ? Bob. Quote Link to post Share on other sites
trchris Posted April 28, 2021 Report Share Posted April 28, 2021 Hi John I used a digital thermometer (the infared type) to check mine after a engine rebuild I think Lidl have/had them on sale at around £15 recently Chris Quote Link to post Share on other sites
Z320 Posted April 28, 2021 Report Share Posted April 28, 2021 Hi John, indeed I often have a different view on thinks, I guess I'm "strange"...? The TR handbrake is a very awful construction because of the assembly around the brake drum, pulling stronger on it does not improve it. Please see my post at this handbrake lever thread and decide your own You also could read Handbraaake (with triple A) There I explain how to lift the cable to avoid friction and not to twist the lever, also how to added a strong spring for more more elasticity. Finally only a swop to a "lever in the drum" construction changes everything. Ciao, Marco Quote Link to post Share on other sites
RogerH Posted April 28, 2021 Report Share Posted April 28, 2021 49 minutes ago, Z320 said: Hi John, indeed I often have a different view on thinks, I guess I'm "strange"...? The TR handbrake is a very awful construction because of the assembly around the brake drum, pulling stronger on it does not improve it. Please see my post at this handbrake lever thread and decide your own You also could read Handbraaake (with triple A) There I explain how to lift the cable to avoid friction and not to twist the lever, also how to added a strong spring for more more elasticity. Finally only a swop to a "lever in the drum" construction changes everything. Ciao, Marco Hi Marco, our step by step change is Evolution Your attack on the final solution is Revolution Roger Quote Link to post Share on other sites
Andy Moltu Posted April 28, 2021 Report Share Posted April 28, 2021 An alternative is to fit the extensions to the levers sold by Hart on eBay. I know there are those who will say the standard handbrake is fine when in perfect condition. I would argue it’s just about adequate at best. Flat back plate, good shoes, adjusted properly and new handbrake cables are ok but the extensions make it so much better. Quote Link to post Share on other sites
RogerH Posted April 28, 2021 Report Share Posted April 28, 2021 19 minutes ago, Andy Moltu said: An alternative is to fit the extensions to the levers sold by Hart on eBay. I know there are those who will say the standard handbrake is fine when in perfect condition. I would argue it’s just about adequate at best. Flat back plate, good shoes, adjusted properly and new handbrake cables are ok but the extensions make it so much better. The extenders do make a very good improvement. Repositioning the cable attachment pivot on the handbrake handle improves it significantly more - especially combined with the above Marco's re-engineering of the lever mechanism is a greater leap in improvement yet again. Roger Quote Link to post Share on other sites
keith1948 Posted April 28, 2021 Report Share Posted April 28, 2021 (edited) attached is how to do 4A handbrake mod (you need to be logged in to see the attachment) Improving TR4A.doc Edited April 28, 2021 by keith1948 more info Quote Link to post Share on other sites
Z320 Posted April 28, 2021 Report Share Posted April 28, 2021 Hi, allow me to add one point about the longer levers: you get less than you might expect from a longer lever - if you can`t also change the point you are pullng from. Because torque is only force x the effective lever 90° to the force. This photo is already some years old. Red is the direction of pulling on the original lever, but the effective lever (90° to the force) is shorter. Orange is the direction you have to pull the original lever to benefit from its full lenght, but you can't pull in that direction and the effective lenght is not much longer. Green points from the fixing of the bowden cable to the the end of a possible end of a lever extension, but the effective lever 90° to the force is much shorter. So yes, you will have a benefit from lever extensions, but it is less than the lever may suggest. Ciao, Marco Quote Link to post Share on other sites
Tr4aJim Posted April 28, 2021 Report Share Posted April 28, 2021 Marco, I think I see maybe why my implementation of the lever extensions had a better result. My TR4A has a live axle. On my car the handbrake cable connects to the lever extension at almost 90 degrees (the pictures are not the best, but you get the idea). Jim Quote Link to post Share on other sites
Z320 Posted April 28, 2021 Report Share Posted April 28, 2021 (edited) Sorry me and YES, I expect less benefit on the IRS axles, more benefit on the live axle, let me add: 90 deg to the visible lever is no guarantee, it has to be 90deg to the effective lever, see the orange lines: pulling 90 deg the effective lever is pasing left of the coil spring, 90 deg to what you might think is the lever is directly to the coil spring - but the wrong direction. Please have a closer look yourself (if you want) Edited April 29, 2021 by Z320 Quote Link to post Share on other sites
John Morrison Posted April 29, 2021 Author Report Share Posted April 29, 2021 On 4/27/2021 at 10:25 PM, Lebro said: Re the temperature gauge reading high - check the voltage stabiliser is connected, & working. Does the fuel gauge read correctly ? Bob. Hi Bob, so the fuel guage works fine. I'm thinking there is no real way to test the sender other than by substitution? John. Quote Link to post Share on other sites
Lebro Posted April 29, 2021 Report Share Posted April 29, 2021 If you have access to some resistors, or a variable resistor then you can. I would need to check on the values required for your car, or RobH may come up with them, as he has before. Bob Quote Link to post Share on other sites
RobH Posted April 29, 2021 Report Share Posted April 29, 2021 (edited) The TR4A sender is around 240 Ohms at cold and 20 Ohms at hot according to the data I have. see actual figures in post below Edited April 29, 2021 by RobH Quote Link to post Share on other sites
RobH Posted April 29, 2021 Report Share Posted April 29, 2021 (edited) Update - I have just found the resistances as measured. This is just one sample and as these are not precision devices there is bound to be some spread in actual value from unit to unit. The TR4A uses the GTR 104 transmitter: temp GTR104 GTR101 deg C. Ohms Ohms 26 554 909 30 524. 849 40 352 563 50. 272 400 60 184 270 70 146 181 80 98 124 90 65 90 99 47 56 Edited April 29, 2021 by RobH added comment Quote Link to post Share on other sites
pfenlon Posted April 29, 2021 Report Share Posted April 29, 2021 So Archimedes was wrong about the lever then????? Quote Link to post Share on other sites
John Morrison Posted April 29, 2021 Author Report Share Posted April 29, 2021 Quick question chaps, is the TR4 and 4A quage the same? John Quote Link to post Share on other sites
RogerH Posted April 29, 2021 Report Share Posted April 29, 2021 5 hours ago, pfenlon said: So Archimedes was wrong about the lever then????? Hi Pete, Archie Medes was spot on but the angle of dangle does take its toll. Roger Quote Link to post Share on other sites
RobH Posted April 29, 2021 Report Share Posted April 29, 2021 30 minutes ago, John Morrison said: is the TR4 and 4A quage the same? According to Revingtons they both use the same sensor John. Quote Link to post Share on other sites
Z320 Posted April 30, 2021 Report Share Posted April 30, 2021 16 hours ago, pfenlon said: So Archimedes was wrong about the lever then????? Hi Pete, if you post a sketch and an accurate question it could be possible to explain (this reminds me of one of my teachers (RIP), this phrase was one of his fovorites). Ciao, Marco Quote Link to post Share on other sites
pfenlon Posted April 30, 2021 Report Share Posted April 30, 2021 12 hours ago, RogerH said: Hi Pete, Archie Medes was spot on but the angle of dangle does take its toll. Roger Ah Ha.... Quote Link to post Share on other sites
stuart Posted April 30, 2021 Report Share Posted April 30, 2021 12 hours ago, RogerH said: Hi Pete, Archie Medes was spot on but the angle of dangle does take its toll. Roger But he did like a good screw! Stuart. Quote Link to post Share on other sites
RogerH Posted April 30, 2021 Report Share Posted April 30, 2021 Quote Link to post Share on other sites
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