Dual Circuit Brakes

[John Morrison]

Question about a standard road going four.

 

Is there a relatively simple way of fitting dual circuit brakes?

 

been trying to think, along the lines of either twin, smaller, master cylinders with appropriate pipework, and a modified Master Cylinder carrier,Or

dual circuit master cylinder that will fit the standard cylinder box,

this been done?

 

John.

[TR 2100]

John,

 

One way (kits provided by TREnterprises, Revington & others)

is the twin mini-bore master cylinders, TR3A-style reservoir and

modified master cylinder bracket.

 

The bores of the master cylinders result in equal braking pressure

to standard, so no need for a servo. There is a mechanical bridge

bar between the master cylinder pushrods.

That is the option I have on my TR4.

 

 

Alternative would be to adopt the TR5/TR6 system complete with

pedals and brackets.

Probably cheaper but not so easy to come by the brackets.

 

AlanR

[stuart]

Alan is that an extra re-enforcing plate going down the toe board below the balance bar I see?

Stuart

[Graze]

I seem to remember Tony Millward saying he had fitted a pressure limiting device to his rear brake circuit to adjust the bias. On that basis couldnt you could just set up a standard dual circuit and fit that to the rear. Much cheaper than buying one of the pre-packaged systems

 

Graze

Edited July 2, 2015 by Graze

[TR 2100]

Alan is that an extra re-enforcing plate going down the toe board below the balance bar I see?

Stuart

Stuart -

 

Yes. A TR Enterprises jobbie. Special bracket made up.

 

This was done some 6 years ago when I had the car restored.

We discussed brakes and it seems the TR4 pedal box leads

to a fair bit of bulkhead flexing.

 

I was considering a TR6 setup as a possibility to achieve dual

circuit brakes, also as the bracket represents a stronger setup

than standard TR4. At that time, small bore master cylinders

of just the right diameter (such that two give the same braking

force as standard) had only come onto the market and so I went

with that option.

 

I don't know if the TRE bracket is still the same, or if it has been

modified over the years.

 

AlanR

[Motorsport Mickey]

Hi Graze,

 

You can fit a Tilton brake valve to the rear brake line which is adjustable for bias of the braking effort if apportioning effort is what's required, available through most of the on line ancillary suppliers.

 

Mick Richards

[Graze]

Thanks Mick

 

That sounds like the system Tony mentioned

 

Regards

 

Graze

[John Morrison]

Alan - thanks for the info.

 

Mick - how does this make the system dual circuit?

 

John.

[Motorsport Mickey]

Sorry John it doesn't, I was answering Graze and supplying a manufacturer who did an apportioning valve so you can change the effort going to the brakes front to rear. Why do you want the dual circuit ?

 

Mick Richards

[John Morrison]

Thanks Mick,

We have an elderly TR 4 driver in our group, who recently lost all his brakes because a brake pipe had chafed

on something, its his question really.

 

I can see Alan's set up working, but it will be expensive,

just hoping there might be a cheaper alternative. I found a guy who has a home made similar set up, twin, smaller bore (5/8ths) master cylinders,these with an integral fluid container, and plumbed

1 for fronts, and 1 for rears,

I understand that rears only might pull the car round in an emergency situation but it made the pipework Much simpler, the logic being that any half brakes were a lot better than none!

Looking at Alans set up, and your point about bias, I'm thinking that the two master cylider pushrods are adjusted to allow for the bias you mentioned.

 

All food for thought, and I would welcome your input, just trying to keep our man driving his TR a bit longer.

 

John.

[ianc]

The brake failure which John describes makes one wonder whether the MOT inspector had done his job thoroughly. The small garage which I use has two testers, both of whom are very thorough, and I welcome that annual independent inspection.

As it happens, my TR4 passed the test on Tuesday with nothing other than complimentary comments. Over the last 22 years of inspections, I've had two advisories, and in both cases I took action as soon as I got home.

Ian Cornish

[BlueTR3A-5EKT]

Question about a standard road going four.

 

Is there a relatively simple way of fitting dual circuit brakes?

 

been trying to think, along the lines of either twin, smaller, master cylinders with appropriate pipework, and a modified Master Cylinder carrier,Or

dual circuit master cylinder that will fit the standard cylinder box,

this been done?

 

John.

I too am seeking such a system for the disc braked Girling TR3-3A.

Not yet managed to do this yet but you are seeking something like this. Twin side by side cylinders in the early cars looks like it involves cutting the bulkhead.

 

http://www.ebay.co.uk/itm/Delphi-Master-Brake-Cylinder-Genuine-OE-Quality-Braking-Replacement-Part-/301389952314?pt=LH_DefaultDomain_3&hash=item462c3db53a

 

The challenge is getting the combination of bore size, flange mount orientation, outlet position and reservoir inlets.

You would need twin remote reservoirs probably. Think about a switch to the TR4 master cyl bracket as it moves the flange mount postion and is wider spaced - you will need to modify your pedals to suit too.

 

One exists I know as I have seen it fitted, but failed to get the information from the owner - Wilwood do something that might do but alas the fluid outlets go straight down.

http://www.ebay.co.uk/itm/like/131536930121?limghlpsr=true&hlpv=2&ops=true&viphx=1&hlpht=true&lpid=108&chn=ps&device=c&rlsatarget=&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0-L&ff12=67&ff13=80&ff14=108

 

Peter W

[stuart]

Peter the setup that Alan has is fairly easy to fabricate out of a TR4 master bracket and wouldnt need to alter the pedals as if you look the clutch master is moved over and the clevis is pinned to the side of the pedal. Like this Racetorations one.http://www.racetorations.co.uk/triumphs-c56/tr3-c4/tr3-brakes-c31/racetorations-kit-dual-brake-master-cylinder-rhd-p505

Stuart.

[stuart]

Thanks Mick,

We have an elderly TR 4 driver in our group, who recently lost all his brakes because a brake pipe had chafed

on something, its his question really.

 

I can see Alan's set up working, but it will be expensive,

just hoping there might be a cheaper alternative. I found a guy who has a home made similar set up, twin, smaller bore (5/8ths) master cylinders,these with an integral fluid container, and plumbed

1 for fronts, and 1 for rears,

I understand that rears only might pull the car round in an emergency situation but it made the pipework Much simpler, the logic being that any half brakes were a lot better than none!

Looking at Alans set up, and your point about bias, I'm thinking that the two master cylider pushrods are adjusted to allow for the bias you mentioned.

 

All food for thought, and I would welcome your input, just trying to keep our man driving his TR a bit longer.

 

John.

Sounds to me like a full inspection of the original setup is required rather than a twin system. I have never had any problems with a properly fitted and maintained system.

Stuart.

[John Morrison]

Thanks Stuart, and everyone else,

If our man does go down the road of something like this,

I'll get all the details and let you know if it works.

 

John,

Edited July 5, 2015 by john

[MRG1965]

Hi all, picking up on AlanR's and others comments above about the TR5/TR6 more modern duel curcuit and servo assisted setup.

Is this a relatively straightforward modificationn to fit this peddle box/servo and master cylinder setup from a TR6 to a standard late model TR4?

I appreciate the pipe work needs modification, which is not a problem, but I'm more interested in if the peddle box fits or can be easily made to fit. I'm assuming it can, but wondered if there is anybody who has done this who can comment.

 

Mark

[stuart]

Its not that easy but it is do-able if you dont mind a bit of metalwork as well as re-piping the front. You need to cut the holes in the toeboard for the servo and alter the footwell top for the clutch master.

Stuart.