The Triumph Dolomite Club - Discussion Forum

I'm considering replacing the front brake callipers on my 1850hl and would appreciate any advice where to buy replacements avoiding the dreaded RBs. Does the club do anything in this line. Tractor boy

Yes, we do. £40 per side on an exchange basis plus £12 carriage (UK addresses).

Fully reconditioned with new pistons, all seals, bolts and nipples, pressure tested and bright plate finish.

Stock imminently awaited

I have a nearly new pair I'll sell. Not sure of origin whether club or otherwise, but £50 delivered if you want them. Ill get some pics later when I'm awake

Tony

A slight deviation, but why do people upgrade their brakes? For instance track cars, anything like that, good brakes are always really important, but surely if you can lock the wheels with normal brakes, then you can achieve 'maximum stopping' with them too?

The kinetic energy (movement of the car) is translated into heat energy through the friction between brake pad and disc (or shoe and drum) which then dissipates as the components cool. When brakes get frequent heavy use, the heat does not have as much time to dissipate, so the brake is trying to transfer energy into an ever increasingly hot disc/drum, to the point where an equilibrium is approached. When this occurs, you can press as hard as you like, but the car won't slow down anywhere as rapidly as normal. This experience is known as brake fade and is quite worrying when experienced for the first time, well, any time actually! It is overcome by bigger discs which can store more heat, and by ventilating them which increases exposed surface area, allowing them to cool more quickly.

The bigger discs also allow a greater swept area between disc and pad.

It is the concept that energy cannot be destroyed, only converted into another form of energy.

has anyone tried to add cooling ducts to standard brake set up,surely it ventilation that is needed

The problem is really down to the size of disc and calliper that can be fitted behind a 13 inch wheel....
and starting with a design meant for about 75 bhp and a top speed of 85 ish...

With an 1850 it was thought sufficient to fit slightly bigger pads and a servo. With the Sprint it was harder pads again and a different servo.
Nowadays you cant get the OE spec Sprint pads unless you are very lucky to find some NOS, and even "pads" sole by other suppliers are the
wrong formula and Ive had sets that dont last 5k miles....

Given modern driving conditions where traffic flows on good arterial roads are pretty fast and more crowded, so harder stops are more frequent, I'm becoming increasingly convinced that 70's Triumphs now need some improvements to mix it safely with moderns on my commute.

If its all in good nick and working right its just about adequate. Periods of indolence will soon give you a couple of sticking pistons that you may not notice round town, but arent up to a sudden long fast stop from an M way cruise, like when you go over a brow and see a rack or tail lights....
One pad overheats and fade is the result....and the last 10 feet is a tad worrying....

I think T-J needs to up production......

Jonners

I've perhaps taken more notice of this since the wife bought a hybrid Lexus. This is very clever in that it converts a lot of this waste heat energy into electricity. So effective is it that you really notice how little brake dust builds up on the wheels on the inside. You get free running from otherwise wasted energy!

Jon Tilson wrote:The problem is really down to the size of disc and calliper that can be fitted behind a 13 inch wheel....
and starting with a design meant for about 75 bhp and a top speed of 85 ish...

I don't agree. How hard would it have been to use a GT6 sized disc and type 16 callipers during production the M16 calipers share the same mounting spacing as type 14, so that would have been very easy? And easily fit under 13" wheels. A few tweeks etc and all would have been good, but I reckon it was own to penny-pinching.

Now, my car currently has no servo, and neither does my spitfire (with way more power, but a bit less weight) The spitfire brakes are excellent, the toledo is pants, terrible feel and so on. And yes, they are set up correctly, and I am using asbestos pads.....

I have just today taken delivery of a remote servo, and I also have vented discs and bigger callipers. The servo will make the brakes "feel" better, but they wont stop any faster. The new discs and ads will make the brakes actually work much better.

You arent really comparing like with like here though....

A GT6 /Spit weighs about 1/4 ton less than a dolly/Sprint....

Owning both the Spit (1500) is fare less prone to brake fade than the Dolly....despite smaller pads and no servo.

Jonners

cliftyhanger wrote:

Jon Tilson wrote:The problem is really down to the size of disc and calliper that can be fitted behind a 13 inch wheel....
and starting with a design meant for about 75 bhp and a top speed of 85 ish...

I don't agree. How hard would it have been to use a GT6 sized disc and type 16 callipers during production the M16 calipers share the same mounting spacing as type 14, so that would have been very easy? And easily fit under 13" wheels. A few tweeks etc and all would have been good, but I reckon it was own to penny-pinching.

Now, my car currently has no servo, and neither does my spitfire (with way more power, but a bit less weight) The spitfire brakes are excellent, the toledo is pants, terrible feel and so on. And yes, they are set up correctly, and I am using asbestos pads.....

I have just today taken delivery of a remote servo, and I also have vented discs and bigger callipers. The servo will make the brakes "feel" better, but they wont stop any faster. The new discs and ads will make the brakes actually work much better.

I've had a GT6 - with GT6 brakes, with and without several different servos operating on the whole system and front only.

My ultimate conclusion (and this is personal taste only) the best setup was with a tiny remote servo from (iirc) a Fiat 127 operating on the front brakes only, closely followed by no servo at all. The first servos I tried, an Austin 1800 Girling Powerstop and a Lockheed from a Hillman Hunter both gave too little "feel" to the pedal and it was far too easy to lock up the wheels, despite the A008 Yokos I used at the time. (Cracking tyre they were, shame they don't make them any more)
13" Steels obviously do fit over GT6 brakes and so do 13" Minilite replicas - but Sprint alloys don't, I tried it! So for the majority of Sprint wheel lovers, the GT6 brakes are a no-go. Oddly, even with the heavy old 6 banger in the front and very heavy road use and some competition, I never got any fade from the GT6 discs, maybe the natural cooling is better. Certainly, I started with new discs and they are quite thick. And the car only had the standard and somewhat miserable 104 BHP, still...........

I drove the Carledo about for a short time with stock Sprint brakes and its Sprint servo not working - and it was frankly terrifying!

After years of defending the stock brakes, do I finally detect a small change in Jonners previously entrenched position on TJs? Well done mate!

Steve

You do indeed...the problem is the lack of "stock" brakes in that you just cant get them anymore with proper pads now a rarity.

Aside from the fact that most moderns are a good deal heavier than dollies there is a reason why Golfs etc have bigger pads and vented disks
so they can get away with the non asbestos sintered chocolate that passes for pad material these days.

Last lot of rear pads on my Golf cant have lasted 10k miles....and on new disks too.

Jonners

As someone who spends a large part of his life covered in brake dust, I have no stomach for returning to "the good old days" of asbestos pads!

You are right though, Jonners, They did work better, not just a bit, but much better. And when you had asbestos pads, a pair of discs would last a lifetime (a cars lifetime that is) instead of needing to be changed after every 2 or 3 sets of pads. With the price of Dolomite discs heading through the roof, the TJ upgrade is not just good for the car's stopping ability, it's financially sensible too!

If you are having trouble with pad life on the rear of your Golf (and IME many do) may I humbly suggest that you avail yourself of a pair of recon rear calipers? The sticking handbrake which is endemic with these is murder on the back pads. It also pays to ensure the pad can move freely in the carrier, even to the point of touching up the pads with an angle grinder!

Steve

The quality of the steel used in modern discs also has a part to play, people tend to fit the cheapest and now that's all that's available.
The difference in weight between some brands of discs is astonishing.

Just talking 1850, what about Rossini disks and Mintex pads?

It's something that I have in mind. Not cheap but a possible quick solution?