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View Full Version : TR5/TR250 4-Piston Brakes for a TR250 - Anyone done this?



RobT
10-25-2004, 03:22 PM
Hello there. I have been "lurking" around this forum for a little while and have decided to leap in with my first post.

I have a TR250, which is fairly original, but with some nice uprates - including tripple ZS carbs, "warm" cam, oil cooler , extra oil feed and electronic ignition.

I am currently rebuilding the hydraulics, and have noticed that Moss Motors (USA) have started offering a 4-piston caliper conversion for TR4, 5/250 and 6s. This kit includes the larger caliper plus slotted/drilled rotors and stainless hoses.

Has anyone installed this uprate? Any impressions?

Many thanks,

Rob.

PeterK
10-25-2004, 05:53 PM
I think that Moss is offering the Toyota 4-pot caliper upgrade that the TR community developed a few of years ago. But theirs is a kit and saves you from hunting the bits. Mine is the home built version with solid drilled/slotted rotors and Toyota 4WD pickup calipers although there is a vented disc version available too(search the web) that uses 4-runner calipers and vented discs (I think from a Corolla). My experience with Moss is that a diy'er could assemble the parts for less the 1/2 of their price. ymmv

JamesWilson
10-26-2004, 10:17 AM
The vintage Triumph registry has a technical article on doing this:

www.vtr.org/maintain/brake-conversion.htm (https://www.vtr.org/maintain/brake-conversion.htm)

I've accessed that before but had a little trouble just now. I hope it will work for you.

I'm in the process of doing this for an Austin Healey 3000- the Dunlop Calipers on it are the same as on TR6s, and everything looks like it will adapt easily enough.

vagt6
10-26-2004, 12:17 PM
A quick question for you TR250 buffs out there: Did the 250 have front discs? And, are the stock TR250 brakes that bad, assuming no major HP mods?

Geo Hahn
10-26-2004, 01:20 PM
[ QUOTE ]
Did the 250 have front discs? And, are the stock TR250 brakes that bad, assuming no major HP mods?

[/ QUOTE ]

Yes, discs. IMO the originals are quite up to the task in the absence of racing conditions or extreme mods. I don't know that the Toyota or other 4-pot conversions really gain anything in terms of stopping distance e.g.

martx-5
10-26-2004, 08:45 PM
[ QUOTE ]
The vintage Triumph registry has a technical article on doing this:

www.vtr.org/maintain/brake-conversion.htm (https://www.vtr.org/maintain/brake-conversion.htm)

I've accessed that before but had a little trouble just now. I hope it will work for you.

I'm in the process of doing this for an Austin Healey 3000- the Dunlop Calipers on it are the same as on TR6s, and everything looks like it will adapt easily enough.

[/ QUOTE ]

Well, it's not working...
I'm in the process of restoring my TR3, and want to go with the Toyota 4-pot calipers also. I have the calipers in my possession (I work for an auto parts remanufacturer that has calipers as one of the lines). I know I need the late TR6 caliper bolts, but need to know what brake line is being used in this conversion. Does anyone know?? And does anyone have a copy of the vtr link that isn't working??

trrdster2000
10-26-2004, 09:04 PM
I hope this will get you to VTR, then give it a search. I haven't read the post but you might try getting one end of you hose the TR side put on the hose for you caliper at a hydraulic hose maker(ie John Deer, or other heavy machinery.) https://www.vtr.org/ Wayne

martx-5
10-26-2004, 09:21 PM
I got on to VTR OK, but that particular section about changing to the 4-piston calipers just draws a URL not available. I looked at the Moss instructions for the conversion on-line, and they showed a brake line that mounted correctly in the caliper and mated with the hard line on the chassis. I wonder if they would sell those parts seperatly??

Geo Hahn
10-26-2004, 10:20 PM
Try this:

https://www.cs.du.edu/~ljanssen/tr6_brake_install.html

trrdster2000
10-26-2004, 11:07 PM
Geo, thanks for the info, not sure if I will do this, but WOW, what a good tech tip. I feel sure someone will want this in the future. Thanks, Wayne

RobT
10-27-2004, 10:14 AM
Thanks for the great link to the Toyota upgrade. Looks like the same parts Moss is offering. I don't want to seem like a car snob, but I really am not sure if I could bring myself to installing Toyota parts on my beloved Triumph. The Morgan rear brake slave conversion looks intresting. Perhaps I will give that a try though.

Thanks,

Rob.

martx-5
10-27-2004, 10:23 AM
Thanks for the great link. That's just the kind of info I was looking for.

Geo Hahn
10-27-2004, 01:27 PM
[ QUOTE ]
...I don't want to seem like a car snob, but I really am not sure if I could bring myself to installing Toyota parts on my beloved Triumph...

[/ QUOTE ]

Me neither but there my wife's old Toyota sits in the driveway with the calipers and 5-speed that are used on TRs.

Not for me but if it keeps people in the LBC hobby and cars on the road then it's a good thing for some.

Winston
10-30-2004, 01:46 PM
Geo,
Excellent post.
how do you feel about the same adaptation for a 67 TR4A (front disc only)

Winston

Geo Hahn
10-30-2004, 08:28 PM
AFAIK TR4s, 4As, 250s & 6s had the same caliper (though the TR4 at least does not have a solid line feeding into the caliper) so the mod would seem to be equally applicable.

Since it is not thought to improve braking distance the main benefit is reduced fade in situations where that may occur... probably not in normal street driving.

trrdster2000
10-30-2004, 09:20 PM
While thinking about this little goody for the front a conversion I saw a few years back on a TR6 running IMSA was the whole kit and caboodle from a Datsun 280 ZX. All I could do was get a picture of the car on the outside, the guy was not the friendly type. I know the U-joints are the same, so the axles would fit up and he may have use the Z,s rearend but the disk brakes looked really good. Wayne

Geo Hahn
10-30-2004, 09:28 PM
Maybe something like this? Follow link to 'Brakes'...

https://www.hottr6.com/triumph/hottr6.html

trrdster2000
10-30-2004, 09:41 PM
u'r the best Geo. Wayne

Simon TR4a
11-01-2004, 12:42 PM
I would just like to offer the opinion that even for racing a brake pad with suitable temperature range will usually prevent fade.
The exception might be a track with a "stop and go" layout.
In street driving I cannot imagine how you would get the brakes to fade, though the conversion may have other benefits.
Simon.

v8triumph
01-29-2005, 02:16 PM
The beauty of the toyota 4 piston caliper upgrade is that it is a truly bolt on upgrade. You can always just swap back the old calipers if you feel the need to go back to stock brakes. From what I can tell, this is exactly what Moss is reselling in their new catalog. I just did this upgrade this past summer on my V8 TR4A and the calipers along with cross drilled Brembo rotors looks great and more importantly, do improve the braking. Next step will be a MC and booster swap as I have never been a fan of the single line MC of the TR4A. You can check this out on my site https://www.v8triumph.com

35thbdaytr6
01-29-2005, 06:34 PM
I did the Morgan wheel cylinder and Toyota caliper upgrade myself using a complete "loaded caliper set" from Autozone. I thought that it felt better, but my passenger grabbbing the dash when I hit the brakes is what told me it stopped better.