cotswold Posted August 10, 2015 Report Share Posted August 10, 2015 (edited) Hello wise ones, I was at the IWE in Malvern yesterday and saw a Servo Kit for the TR4A. I spoke to the guy on the stand who said the kit included all the bits save for the connection to the manifold. I quickly walked around the TR4A section with their bonnets up outside and saw various methods of connecting the hose. One included a T piece from that twisted breather pipe thing with a flat disc and and a spring (does this actually serve a purpose?) and others had hoses attached to the carburetors. If anyone has pics of their set up that would be excellent. I do not want to remove the manifold for drilling and tapping. I am fine with the set up as is but I want my wife to drive the car when we go to France and Italy so it would be easier for her with a servo. I think I would mount it on the passenger side bulkhead where I have seen a few on other cars. Pics please Thanks Charles Edited August 10, 2015 by cotswold Quote Link to post Share on other sites
RogerH Posted August 10, 2015 Report Share Posted August 10, 2015 Hi Charles, the "twisted breather pipe thing with a flat disc and and a spring (does this actually serve a purpose?) does actually serve a purpose and almost works. It is part of the crankcase breathing system. On the TR4 and earlier cars the oil fumes were dumped overboard. The PCV takes it back in the engine via the carbs and it comes out the back - much nicer. Roger Quote Link to post Share on other sites
ctc77965o Posted August 10, 2015 Report Share Posted August 10, 2015 Charles, Put a "T piece" in the hose between the manifold and the PCV. Connect your servo to the T. Neat n simple. Dave Quote Link to post Share on other sites
Rosy Posted August 10, 2015 Report Share Posted August 10, 2015 Here is my installation - servo from TR Shop London - works perfectly. The manifold was removed and drilled and tapped for the connection (where the breather inlet is on the 4A) Hope it helps! Brake pedal is very light with the only downside being it is very easy to lock up the rear wheels! Quote Link to post Share on other sites
ianc Posted August 10, 2015 Report Share Posted August 10, 2015 Surely the best tip is: don't fit a servo. Car only weighs a ton and even a 10-stone, mid-70s old man can stop a TR without need of a servo! And once wheels are locked, the car is no longer under the driver's control. Ian Cornish Quote Link to post Share on other sites
RogerH Posted August 10, 2015 Report Share Posted August 10, 2015 Hi Ian, it is for Charle's wife. Roger Quote Link to post Share on other sites
cotswold Posted August 10, 2015 Author Report Share Posted August 10, 2015 Thanks all, I guess it's the T adaptor on the breather then (helpful pics too thanks Dave) if I go ahead with it that is, there are many of these servos out there but I have not heard of the rear brakes locking up from anyone before, I will raise it at the next meeting. Charles Quote Link to post Share on other sites
Geko Posted August 10, 2015 Report Share Posted August 10, 2015 Check out this tread I still have a premature rear brake locking problem after installing a servo. Quote Link to post Share on other sites
graeme Posted August 11, 2015 Report Share Posted August 11, 2015 Thanks all, I guess it's the T adaptor on the breather then (helpful pics too thanks Dave) if I go ahead with it that is, there are many of these servos out there but I have not heard of the rear brakes locking up from anyone before, I will raise it at the next meeting. Charles Charles, Based on my experience with the servo fitted to my TR4A, I would suggest that there is a problem with the front brakes if the rears are locking first. The servo does not alter the balance of the brakes at all, it just reduces the effort required to achieve the same force. If your system is good then the servo is a sensible addition, after all Triumph engineers added one to the next model! Cheers Graeme Quote Link to post Share on other sites
RogerH Posted August 11, 2015 Report Share Posted August 11, 2015 Hi Graeme, they fitted the servo to the next model to attract girls and hairdressers Roger Quote Link to post Share on other sites
ianc Posted August 11, 2015 Report Share Posted August 11, 2015 TRs with disc front brakes and with 10" rear brakes having 0.75" slave cylinders can be over-braked at the rear. Depends to an extent on the material in the disc pads. My brother's TR3 would lock its 10" rear brakes, whereas my disc-braked TR2 (with 9" drums at the rear) never did - so the TR2 stopped more rapidly. To reduce the problem, one can reduce the size of the slave cylinders in the rear brakes - I think the first step is to 0.625". Ian Cornish Quote Link to post Share on other sites
dbug Posted September 1, 2015 Report Share Posted September 1, 2015 I used a servo off a BMC land crab on my TR4 and on the 4A without any brake locking issues - braking system on both being in good order prior to fitting servo. As said servo fittment just reduces pedal effort, and does not affect brake balance. And as for saying " And once wheels are locked, the car is no longer under the driver's control", the answer is don't lock the wheels!! - same answer with or without a servo Quote Link to post Share on other sites
monty Posted September 11, 2015 Report Share Posted September 11, 2015 Surely the best tip is: don't fit a servo. Car only weighs a ton and even a 10-stone, mid-70s old man can stop a TR without need of a servo! And once wheels are locked, the car is no longer under the driver's control. Ian Cornish Agree with Ian. I have Green Stuff pads on the front, slightly uprated shoes on the back, no servo. Works fine, no lockups yet & the wife can drive it! Quote Link to post Share on other sites
trerynn Posted September 15, 2015 Report Share Posted September 15, 2015 And a NON return valve to the servo, stops nasties getting down the pipe to the servo unit. Quote Link to post Share on other sites
Ian Vincent Posted September 16, 2015 Report Share Posted September 16, 2015 I fitted a servo to my TR3a and it has proved to be responsible for some strange behaviour from the brakes and led to me disconnecting the vacuum pipe from the manifold. Without the servo the brakes take a bit of getting used to after driving a 'modern' but the do lock the wheels if needed. I live in Devon and we have lots of narrow lanes so I have had plenty of opportunities to check that they are still effective. I will leave it until the winter before I decide whether to remove the servo altogether and re route the brake pipes or to strip and repair the servo. Rgds Ian Quote Link to post Share on other sites
tonycharente Posted October 7, 2016 Report Share Posted October 7, 2016 Hello all, Does anyone know the part number for the "t-piece" / "t adaptor" used on the TR4A to link the brake servo vacuum pipe to the mushroom PCV and the inlet manifold vacuum pipes, please? Many thanks Tony Quote Link to post Share on other sites
Geko Posted October 7, 2016 Report Share Posted October 7, 2016 AFAIK there's no part number as this is an aftermarket accessory. I used a copper "T" piece 10 mm inner dia out of the hardware shop Quote Link to post Share on other sites
tonycharente Posted October 10, 2016 Report Share Posted October 10, 2016 AFAIK there's no part number as this is an aftermarket accessory. I used a copper "T" piece 10 mm inner dia out of the hardware shop Thank you for your rapid reply, and I will do the same. However assuming (???) that some TR4A's were delivered brand new with brake servos you would have thought there would be a part number for the T-piece? Quote Link to post Share on other sites
Geko Posted October 10, 2016 Report Share Posted October 10, 2016 Yes but weren't. Quote Link to post Share on other sites
Allan Westbury Posted October 10, 2016 Report Share Posted October 10, 2016 Hi, I fitted a servo to my 4A some years ago & am generally happy with the result. Yes the wheels can lock up if I brake hard but that applies to any car without ABS. With respect to your wife she is unlikely to be as heavy footed as some of us. I have fitted 1144 brake pads to the front discs and will generally lock the fronts rather than rears although to be honest it is not very often. I much prefer the more solid performance the servo gives & would recommend it. I fitted a fast road cam a few years ago & was advised by TR Enterprises to dump the breather valve as it would affect performance. This then gave me the ideal take off point for the servo - or so I thought. advice from a different source said I was better to drill & tap a hole in the center of the inlet manifold as this would equalise the effect on the vacuum to the carb pistons. If you are keen not to drill the manifold then I would use the breather valve inlet pipe on the manifold & feed a breather hose from the rocker cover to an oil catch pot on the bulkhead. i don't know what adding a brake servo would do to the vagaries of the breather valve in terms of inlet pressure, but it surely cannot help? Be sure to use decent vacuum hose to the servo. Quote Link to post Share on other sites
peejay4A Posted October 10, 2016 Report Share Posted October 10, 2016 There's no flow so attaching the servo to the existing breather takeoff is not a problem. 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.