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Triumph TR6 - Toyota calipers anmd brembo discs

My front brakes are obviously trash. Has anyone had good/ bad experience with the Toyota truck calipers as opposed to having White Post rebuild mine at $80.00 a piston? My car is the unusual 76 TR6 with the metric filttings. Price in the end probaly is close either way. Also I have seen advertised Brembo discs at $37.00 vs Moss at $35.00. Is there any real diference other than the famous name?
Thank you.
Richard Porter

Errors always creep in, my e-mail is wrong and I have dificulty spelling the word and.
Sorry
Richard Porter

If you are like me and have "membered up," but typically don't bother to sign in, go sign in and look in the archives under rear disc brakes caliper conversions. If you haven't "membered up," go do that so you can search the archives. Search under brakes, disc, caliper, Toyota, etc. There is a fair amount of information out there on this conversion. The only real downside that I see is that the Toyota caliper is about 2 pounds heavier as I recall.

I have done the Toyota caliper bit. It should be a bit easier for you as your car will already have the bolts with the larger diamater shanks, so you will not have to make up bushings (I tried ordering the later bolts, but they seem to be on permanent backorder from both TRF and Moss). The part that I had the hardest time with was in fabricating the hard lines. I finally threw in the towel and had my brother in law make them up for me. I could get the bends with no problem, but the double flaring was killing me. Found out later that someone I know had similar problems with that company's double flare set up. Bottom line, use a good tool for the flaring and save yourself some trouble. The one from Mac tools is the one to get if I am remembering correctly. This tool topic is specificaly mentioned in one of the archive threads by brands.

I was also running the .875" bore rear wheel cylinders, but took the car off the road for some much needed work and it will be a while before it hits the street again. I will probably put it back on the street with that same set up. I wound up getting side tracked with other stuff and back burnered the rear disc set up with parking brake stuff I had been working on. Maybe when things get a little more sane and I have the TR6 up and going again.....
SteveP

Thanks for the info Steve. I just reuped as a member, lot of e-mail problems recently and new werver. I will check the achives. I was aware of the bolt issue and glad I have a 76. Do you see any balance problem with keeping the stock rear wheel cylinders in place. I think they are .75 bore.
Richard Porter

I don't really have any idea how the balance would be with the .750" bore cylinders. I changed calipers and rear wheel cylinders at the same time, so I have no actual "feel" impression for what it would have been like with the smaller bore (either the .700 or .750) cylinders. With the larger bore cylinder, I didn't notice any balance problems or at least not so far. Since the TRs have a rear weight bias, this is a help in keeping the rears from locking even when the rears are unloaded somewhat under braking. Since the large cylinders are not a problem, I cannot think of anything off the top of my head that would make for a probllem with the smaller ones.

I can tell you that the pedal travel is noticably longer since you are moving more fluid. It had a bit of a pucker factor at first, but then I got used to it. The down side is that you will see much greater impact if there is a master cylinder problem of any type since it is near the limit of its capability to work with both the four piston calipers and the large rear cylinders. There is a late XK motored XJ6 (not XJ40 type XJ6) master cylinder with a larger bore that can be used, but that will increase pedal effort for the same amount of pressure applied out at the wheels. I don't think the extra effort would be a problem with the servo on the TR6. When I get around to the four wheel disc brakes, I think that I will be forced to go that route or some other alternate. I just don't think that the stock TR6 master cylinder will be able to move enough fluid for the large calipers up front and a set of calipers in the back too. It just goes to show you, it's always something. We call it the Trickle Up Theory.
SteveP

I also had so funny things going on up front about a year ago. Ended up changing out the bearings, new rotors from TRF, and rebuilding the calipers. Although I didn't "split" the stock calipers, I did remove the pistons and cleaned them up real well (Mother's Chrome Polish), blew out the passages, then resealed, assembled, and went to silicone fluid. That was actually a snap to do.

Brent
'73 Sapphire Blue
Brent B

On my TR3A, I changed the front brake pads at 43,000 miles. These are still in the car and I read over 155,000 miles on the Odometer now with 112,000 miles on these pads. At 80,350 miles, my neighbour skimmed about 0.005" off each side of each original front rotor and these still look like new.

I agree with Brent above - why change something for more "new" or "different" problems - if repairing what you have will do the job ?

Don Elliott, Original Owner, 1958 TR3A
Don Elliott

Don, the "Why" part is a matter of what you want to do with the car and the circumstances. In my case, it is a toy for me to play with and the traffic pressure demands brakes that are more up to the task. Modifications are not for everyone, just like having a 400 point concours trailer queen is not for everyone. If you want to play, you have to pay and what and how you pay is determined by the manner in which you play. If you want a 400 point trailer queen, you pay top dollar and/or your time for a car that will see little real world use. If you want a car that is a driver and pretty much no fuss, no muss, you stick to pretty much stock and can actually use it as a car if you wish. If you want to modify, you can still use it as a car as long as the mods aren't too wild for the street, you have to remember what is what and where to get bits, it cost money and time, and is usually more maintainance intensive.

To talk specifically about brakes, in my case a large part of it is tied to where I live and how people drive. This is a major urban area with loads of traffic and rather high speeds. An example of the speeds, I was driving my daily car on our local loop (I-285), heading over to the shop to work on my TR6 (now sitting in major disassembly mode). I was driving about 70 mph in a 55 mph posted zone. I was being passed by as many or more cars than I was passing. Our local county police have stated that the speed are high enough that they don't even typically ticket for under 80 mph on the freeways around here. Now put those brakes that were pretty good in the sixties and seventies against modern brakes at those speeds and you have a potential disaster in the making. Hence my desire for more and better brakes.
SteveP

But are they "more and better"? You did complain about the extra pedal travel since the caliper cylinder's are bigger... that will change the road feel. Hopefully the pads in the Toyota assembly have more area as well, otherwise there's no benefit as long as the pedal can be pressed hard enough. Personally, I've not had a problem with the stock brakes - I can (and have) lock them up if needed. After that, it's a tire/road problem.

I guess my point is that the braking problem I was having was due to a sticking/frozen piston. After 30 years, what can you expect. But after cleaning things up the brakes work fine! Using silicone bf should keep water and corrosion out, so I doubt I'll have to touch the brakes again. And I'm touchy about brakes...

Brent
'73 TR6
no dents
Brent B

Interesting. I never hesitate to change my car if I think it will work better than originally designed. For example I changed the stock heater valve for a Honda Civic valve and have never regretted it one bit. However I do not want to change the character or essence of the car - that is why I owne a TR6. I think it just looks and feels cool but in some respects needs a little polishing.
I had heard about the extended pedel travel but it seems to be something I would be able to deal with for better brakes. The numbers I have seen comparing braking distances certainly are an argument in favor of the Toyota brakes. I noticed in one web site this conversion is popular with Datsun 240Z drivers so it must be worthy of some consideration.
Richard Porter

Nothing wrong with tinkering since it keeps you in the garage and out of trouble! I suggest that before one opts for a toyota coversion you might want to try a set of real performance brake pads like EBC "green" or similar. I find the stock triumph brakes when properly set up to be really very good - and speaking from experience they are much improved with a set of performance pads.

I dont have any experience with the toyota mod apart from having read lots about it but I understand that they are heavier thus adding unsprung weight -which is where its best not to ad for performance handling. You can get from the UK a lightweight wilwood 4 piston setup but it is pricey.
Michael

My brakes are great - it is well known that Triumph brakes exceed modern standards re weight versus surface area. Why not get the brakes you have, working as they should, instead of wasting all this time and effort on an unnecessary upgrade.Unless you are racing, and even then, when you can lock up at any speed, how much braking do you need ? Peter
Peter Gooch

I refreshed my braking system by rebuilding the front calipers, replacing the rear wheel cylinders, new rotors, racing pads and stainless steel brake lines.

I drive my TR to work in the summers and my commute consists of a 110 km per hour speed limit that often comes to a complete stop on a very high accident rate highway.

I'll tell you - with all the work I did to my TR brakes, I have a hard pedal and the car stops hard.

Really no need at all for the Toyota thing unless you are on a vintage race track.

John Parfitt
Calgary, Canada
73 5 speed.
John Parfitt

Regarding my "complaint," it was more an observation than complaint as I indicated that it "had a bit of a pucker factor at first, but then I got used to it." As for the stock braking system vs. what I have done, it is not just the calipers, but also the larger bore rear wheel cylinders. I traded several e-mails and a couple of phone calls with John Lye on the subject before proceeding. If the front caliper conversion alone is done, then statistically the Toyota calipers provide slightly better stopping distances, but when standard deviations are taken into account from John's trials, there is some overlap between the stock set up and the Toyota front caliper set up as far as stopping distances are concerned. As for pad size, the pads for the Toyota caliper are considerably larger, otherwise I would have to agree and say why bother. I made a point of weighing both the 16P caliper with all hardware and pads and the Toyota caliper with all hardware and pads. The Toyota caliper was about two pounds heavier, less than a kilo delta between the two. Not an ideal situation, less is better, but one I can live with. We played size games and calulations with some Wilwoods for the front, but decided not to go that way for a street car.

The hot lick in decreasing stopping distances is when you change the rear cylinders along with the calipers. Again going back to my own experiece autocrossing a TR6, the car had a tendency to lock up the fronts as opposed to the backs in straight line stopping. With the rear weight bias in the TR6, you can stand more brakes on the rear before rear lock up becomes a problem. The use of larger rear wheel cylinders was an old SCCA club racing trick on these cars before SCCA allowed the use of rear disc brakes on them along with alternate brakes up front. Getting back to John's trials on the Toyota caliper/.875" bore rear cylinder set ups, the average stopping distance was reduced by 47 feet (262 vs. 215) and taking even a worst case deviation into account, there would still be a noticable improvement with the Toyota caliper/.875" bore rear cylinder set up compared to stock (243 vs. 224).

(Note for you mathematics majors out there, I am well aware that the population of samples in these trials can be argued to be statistically insignificant. However, from my own experience in development and test labs before they chained me to a desk, there are methods to provide a pretty good estimate of a standard deviation when the populations are small. Sort of goes back to an arguement I had with a prof in one of what seemed like too many calculus classes on the difference between scientists and engineers......no point in rehashing MTH 2307)

What all of this means is that there is some small benefit to be gained from going the Toyota route alone. If you really want to see an improvement, you have to do both front and rear. As for going to disc brakes on the rear, to be honest I don't know that there will much improvement, if any, with the single piston-built in parking brake set up. I put it more in the category of it's something to do to show that we can, if it is the same or better, great, if not, then off it comes and back to big bore cylinders and drums. The set up with the four piston calipers in the rear, that does indeed work but it is in reality a race use set up for current club racing. As a rule, most vintage race organizations intend that the cars be raced as governed by the rules of the appropriate era, so that means no big calipers up front, no disc brakes in the rear on these cars. Check with the sanctioning bodies as rules do vary.

About four years ago I could have used that shorter distance when some bonehead travelling at what must have been triple digit speeds ran out of talent on I-285. He came across all lanes of traffic from the inside lane outward, crossed a median, then crossed a two lane wide entrance ramp from I-75 to take out a Maxima on the ramp in front of me. Before it was all said and done, he had gotten the Maxima twice, a Mazda 626 out on I-285, a Land Rover Disco which was knocked into an 18 wheeler and the very right hand front corner of my TR6. Some of this happened behind me, some in front and some to my side, but if I had just a little more brake I would have had the foot or so that I needed to snake my way through the sheet metal carnage and avoid it all instead of taking that glancing blow on the corner. The only vehicles that left that incident under their own power was the 18 wheeler and a certain signal red TR6. On the plus side, this incident is why the car is in major disassembly mode now. I got tired of being reminded of it everytime I looked at the car since the red matching is such an problem. I stripped the car, had it painted, decided to go through the suspension and steering again since it had been a while, and will be going back with new interior, top, new headliner for the hardtop, all new seals, etc. When I get through with this one, it will be time to move onto the TR250.......this stuff keeps me occupied and out of trouble most of the time.
SteveP

I cant see the need for ever using a 2 or 4 piston caliper set up in the back (apart from trying get rid of some weight and maybe for extreme competition purposes where you might be getting rear brake fade). The physics of braking is that simply the front brakes do most of the work. Hard braking shifts weight forward - the faster you do it the more weight transfer that occurs - it takes very little braking to lock up the rears when there is little weight there. Just as you can upgrade the front disc pads for a considerable improvement you can upgrade the rear lining material (ie for more friction ) as well. I expect that there would be an economical yet more than sufficient improvement.
Michael

Hey Steve,
I'm not knocking the upgrade, and from what I've seen of your posts you certainly know what you're talking about when it comes to TR6's. But that upgrade is not for everyone - it's not quite the same as a Bosch alternator, for instance.

My hairest stopping problems come from wet pavement, sand/gravel, and lo it be said, wet leaves. The brake upgrade offers no help there. But if you're largely a high speed interstate driver or racer, go for it!

I am not at all familiar with racing brake pads or EBC "green". Are those metallic (yuk)? Please - how about some more info.

Brent
'73 TR6
Brent B

Hi Steve, I have exactly the same setup on my TR6,
Toyota 4 pot calipers/.875"rear cylinders and I find them superior to the stock set up. In addition I've added the stainless steel braied brake hoses and a niffty little gaget that brings the brake pedal back up where it should be. A vacuum cansiter made out of a old hand held propane bottle. Make sure it is completely empty, drill out the two valves,(the top main valve and secondary safety valve} so they eccept a standard metal fuel line. About three inches of line per hole.
These will form the nipples that the vacuum brake lines
will fit onto. A bit of silicone sealant will secure each fuel line nipple to the propane canister.
Then simply attach the brake booster line and the intake manifold line to either of the nipples from the
propane/vacuum canister and there you are.
Normal feeling brakes.
I got this tip off of Les Shockey at this summers
TRF summer party in Pennsylvania.
Christopher Trace

Chris, a vacuum reservoir, mmmm, I like that. I had not really given one much thought since it is primarily a fluid movement problem, but if there is more vacuum for boost available, there would be an effect on effort and travel. Long ago, in a state far, far away, I had fitted a car with a vacuum reservoir because it had a pretty wild cam in it (therefore it didn't have a lot of manifold vacuum available) and hadn't thought about it until you broached the subject. It was done for a different reason, but could still be applied here. I think we may just have to give that a try as we put the car back together. Then there are the stainless braided brake lines, got those too, but forgot to mention them. With your motor set up and speed potential, big brakes are an excellent idea. Hats off to you and Lee on this one.

I must admit that I was somewhat puzzled with the responses on this thread. It's not like all of the postings here are from folks whose cars exist in a modification free zone. Add a vacuum advance where there was a vacuum retard before, three Strombergs instead of two, five speed transmission instead of a four speed or a four speed with a Laycock unit hung on the back, high amperage alternators that have the potential to put out sufficient amperage to overheat wiring harnesses are modification stated in other postings. Chris' V8 motored TR6 has been mentioned on several occasions. With the possible exception of the 65 amp alternator (55 amp should be a max to my mind since heat generated in current transmission is square function of amperage and the TR wires are not really that heavy a gage), none of those things bother me and don't elicit the big "WHY?" But for some screwy reason, you mention brake modifications on this board and it's like you have set someone's pet on fire. Even something as simple as bypassing the instrument lamp rheostat is a modification, how many out there in TR6 land have done that?

Green pads, blue pads, black pads, red pads, they represent different pad compounds and are specific to a given company if that company chooses to color code their pads. Pad compound discussions should be saved for another time, very complicated subject that. Just remember that unlike most front engine cars, under static load conditions the TR6 is tail heavy (about 46% front, 54% rear nominal, some minor variance by year during the production run). Even with weight transfer forward during braking, there is still proportionally a lot more weight on the rear wheels than with most cars. This means that the rear brakes on a TR6 can be used to do more of the braking than on most cars and improved rear brakes translate into shorter stopping distances for these cars.

The root question at the top was what experience have you had with the Toyota caliper set up, good or bad. So folks, pony up some answers to Richard with your Toyota conversion experience. If you have anything to add on Moss supplied vs. Brembo made replacement disc, you should pony that up too.
SteveP

Well well well. What a controversy I have started with a simple, I thought, question. I have decided to stay with the stock setup and just ordered parts from everywhere. The reason is not because I do not like the Toyota route but because I know I can rebuild the stock system without having to make any modifications which would be timeconsuming and possibly beyond my skill level. Once I get a new base line I will look into improvements to the system. I just want to get this car back on the road before I die and/or we run out of gas.
Having read all this I still guess I most agree with Steve from Marietta. I do not see any problem changing the cars to meet our expectations and levels of performance. Even if the change is slight if it makes me happy I will make the change. By the way Steve I was in Atlanta about 4 years ago and loved the place but not the drivers. You really take your life into your own hands when you travel on the freeway.
Richard Porter

Richard, You'll find the stock brake set up will be just fine.When I had the stock set up I was very pleased with it.As long as you keep the pads thick and the fluid fresh you won't have any problems.
The only reason that I changed over to the Toyota
system was sometimes I get going a bit too fast and
I like knowing there is real help available on that
other pedal when I need it.
Keep us posted, those of us that have been through
the restoration ringer love to help someone else not
to make the same mistakes we did.
Christopher Trace

Im not trying to rain on anybodies parade nor am I against modifying my TR - I think that with some tweakin' here and there you can have a really very much better performing car (and one that looks better too like for example proper stance instead of the jacked up look.) Sure Ive got my own preferences too. I am also just adding another perspective to better the cause!

Pads are very relevant here -you simply cannot talk about performance brakes without talking about pads. Real performance pads have higher friction and no these are not just pretty colors - this is fact and not just my opinion. Your research will confirm that. I wonder how many people that change to toyotas still use a non performance pad- rhetorical question please dont reply! Same with the discussion on rear braking. Im not knockin it I think a rear disc setup is desireable but not for the braking: I expect the real gain would be in reducing unsprung weight (taking out those nasty 15ib? drums) thus improving the suspension.

Steve, Im not trying to start an arguement but my eyebrow is raising here.I dont see how under any type of braking the rear are doing anywhere near 50% of the braking unless your using your handbrake or your wife is really heavy and sitting on the bumper(really Im just kidding!! just trying to add some comic relief). Why else would Triumph put big discs up front and not all the way around?

Brent, EBC "green" pads are designed for street use ie they are good for all temperatures (race pads in comparision operate properly at higher temperatures and thus are not suitable for causal use)and are easy on rotors. I think the material is kevlar or some blend -not sure though- but you can probably get that info from their website or web search. EBC uses colour to designate the compound and use from street/ strip to full serious race. There are other brands also I am not an EBC salesman but Im just familiar with using their products.
happy motoring
Michael

I looked into pad variations - the EBC "green stuff" is a Kevlar blend. And "racing" pads are probably out due to poor cold performance. I'm not too keen on metallic or semi-metallic due to high rotor wear. On top of that it looks like the EBC, Hawk, and Performance pads aren't made for a '73 TR6 anyway - the pads are for 1/4" pins rather than 3/16" (check out the Moss catalogue). So what do people do - slap the 1/4" pads in anyway?

Brent
'73 TR6
Brent B

Interesting topic for discussion, obviously others think so too. I will try to keep my comments brief.....
1) If you can lock up your brakes with the stock brakes ( you definitely should be able to)then the way to stop quicker is too increase the grip the tyres have on the road.
2) Having good shock absorbers helps keep the tyres in proper contact with the road, poor shocks increase braking distance.
3) If you use high performance tyres with more grip or race tyres withmuch more grip, there is a case to be made for upgrading brakes, especially if you will need to do several hard stops in succession.
4) Change your brake pads if they are much more than 50% worn, the pad material provides some insulation, reducing heat transfer to the caliper and fluid.
5) Change your fluid every two years or even every year, pump it all out and replace with fresh.
6) Make sure the front/rear brake balance is correct by adjusting the "clickers" on the rear drums. As the drum linings wear the rears do less work and pedal travel gets longer, but slowly so you don't notice in normal driving.
7) Datsun 240z rear brake drums work well on TRs; they are aluminium with fins cast into the outer edge, 3lbs lighter each and better heat disipation.
8) Stainless flex hoses (and stiffer calipers which will not flex under heavy loads) improve braking feel, allowing you to get the most out of your tyres grip.
9) I use stock calipers with Repco (now Axxiss) semi metallic pads, have had NO problems with wear on either stock rotors or cross drilled Brembo rotors. I use 550 degree Ford heavy duty DOT 3 brake fluid and have only ever had brake fade at one track, Cayuga Road Course. These pads work well for street except that they require a firm push on cold wet days.
10) Final point, to your enormous relief no doubt, if you change calipers the pedal travel issue can be corrected by changing the diameter of the brake master cylinder so the same pedal arc moves enough fluid to move the pads the same amount. Of course this means a non Triumph master cylinder.

I applaud all those with high performance cars who upgrade the brakes to match, for most of us good maintenance is probably enough. Sorry it was so long! Simon.
Simon Rasmussen

The EBC pad to use for a TR6 is one listed for a Ford Cortina - I have the part # somewhere here. I have a 73 TR6 and am using them without any problem and they looked identical to stock (though I didnt thouroughly scrutize them.) I dont know what size the pin is.
Michael

Does anybody on the list have follow up information about a recent 6-pack post re using a 1988 Nissan Master cylinder and servo? I am happy with the original system which is in the final stages of being rebuit to original specs but am always interested in new and possible better ways of doing things. Just curious, no intention to cause controversy.
By the way just fired up the TR6 for first time in long time after rebuild and wow engine pulls well seems very smooth and idles well. Looking forward to the open road. Had small problem which I had never heard discussion about but is worth looking for. I rebuilt the carbs but did nothing to the floats or their attachemnt to the metal shut off valve. They are held on with three cotter pins. Firsr time firing up I had gas out of the back carb. I took it apart and it was clear that one cotter pin had rotated to the point that one leg was just long enough to prevent the valve closing. I hear airplanes have specs for cotter pin length just to prevent this problem. Sorry for long ramble but was obscure problem I had never heard of and just wanted to share.
Dick
Richard Porter

Regarding Chris Traces comment on Sept. 1 about adding a vacuum reservoir to the brake system:
Chris, I have the same brake set-up awaiting install on my '75 TR6 and have a few questions.
I'm curious about the size of the propane bottle and where you installed it -- are there any pictures available that you could share ??
Are there any downsides to the 'extra' chambers use ? And last - are there any better ways of doing the installation now that you've lived with it for a short while ??
Thanks for taking the time to share this information --
David J. ---
Seattle, Wa

David Johnston

Hey David,
We got to get together so I can see your toy
Don K.
DON KELLY

David,
The size of propane bottle I used is one those
hand held types generally used for melting solder
for plumbing work. You could also use one of the Coleman camping propane bottles. At the moment
the bottle is straped in on that little shelf
behind the brake and clutch M/C s But this winter
will place it sideways on the shelf where the battery
use to be.(it is now in the trunk)
I have a feeling from what SteveP says that the
canister works for me because my cam is a bit
on the hot side.It may not have much effect on
a stock motor. But give it a try, it only take ten minutes to make one.
Christopher Trace

I have continued this line of discussion in a new thread "Extra vacuum for brakes"

R
Roger H

Thanks Chris for the info and Roger for continuing the thought process. Don,
give a call over the weekend -- I'm in the midst of installing hi-ratio roller rockers
you might get a kick out of parts everywhere ! (Hopefully, most will stay in the motor)
Now to the new thread ...
David Johnston

This thread was discussed between 30/08/2003 and 10/10/2003

Triumph TR6 index

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