TR2/3/3A Fitting on Moss Brake/Clutch Masters

[mastaphixa]

The new masters I have received from Moss have a black fitting with a copper washer installed on the output port. What is the purpose of this fitting? I have removed it and the brake line fitting threads in to the master nicely and I can't see any difference in type of seal between the brake line and the master with or without it. Obviously not having the fitting installed would allow my brake/clutch lines to line up as they had to the previously installed masters. The black fitting changes the geometry a bit. Nothing I couldn't overcome, but I just wondered what the intent of the fitting was.
Thanks,
Steve

 

[ShawnC_at_Moss]

Steve,
What part number did you order?

Shawn

 

[mastaphixa]

Shawn,
It looks like part number 581-010. Thanks

 

[ShawnC_at_Moss]

Steve,
I am not the tech guy but looking through 20 years of our history on this master cylinder, all our photos have an adapter. In our tech write ups of the product the adapter isn't even mentioned. We usually do that when it isn't anything special. I did find one reference to the adapter that noted, and I quote "Adaptor supplied with master cylinder is 3/8 UNF male to 3/8 UNF female with a male cone seat." I read these as saying your brake pipe would thread into the hole with the adapter removed but requires the adapter to seat correctly. Perhaps 60 years ago the adapter wasn't part of the set up but with supercessions and generalizing going on the adapter became part of the package. I do have an email in to tech to see if they have a different perspective.

Shawn

 

[mastaphixa]

Shawn,
Thanks for your interest and support!!

 

[ShawnC_at_Moss]

Steve,
According to our tech department the adapter, for your Triumph, can be discarded. The outlet port of the cylinder also has the male cone seat. The adapter is likely for an Austin Healey or other applications.

Shawn

 

[mastaphixa]

Thank you very much!!

 

[RandyInUtah]

Just went through this adapter business with my master cylinder on my TR3 because the steel brake pipe would not seal at the adapter. I tried removing the adapter and and threading the brake pipe in and it would not seal at all fluid just poured out. FWIW I feel the reproduction master cylinders are not machined for a direct fitting of the steel brake pipe thus the adapter is needed. To correct my leaking problem I had to re do the flair on the original steel line. The original steel line had a double flair which was not making a good seal on the adapter. I put a single flair end on the steel brake pipe and it stopped my problem of brake fluid weeping from the line to the adapter.
I would be interested if others have had this same problem with the reproduction cylinders leaking at the adapter.

 

[Chuck Murphy]

I believe that MOSS must of, unfortunately, changed suppliers for their Brake/Clutch master cylinders some time ago. The master cylinder I got from them in the 1980's did not have an adapter - the original "Triumph" steel brake line fit into the master cylinder and sealed just fine. However, the one I got from them in early 2016 had an adapter on it. My finding was that the original "Triumph" steel brake line would only work if you used the adapter. However, if you have for some reason replaced your original 'Triumph" brake line with the new copper/nickel lines from MOSS that use a "Universal Flare" then you do not have to use the adapter.
Moss talks about the Universal Flare in the brake lines section of their catalog (but does not talk about master cylinders, unfortunately).
I wish Moss would explain when you need (or do not need) the adapter in their catalog or with an instruction sheet along with the new master cylinders.
Chuck

 

[mastaphixa]

I am not sure what to call the flare that is on the brake and clutch lines coming from the masters to the various slaves, but it is not a single or double flare. It has a flared back that the captive threaded fitting presses on, the sealing face appears to be a rather rounded affair. I have never seen anything like this before. So far they are sealing well without the adapters, but I have only been through the first round of bleeding after purging a mix of dot 3 and dot 5 out of the brake and clutch system. As I progress with that and use the car a bit, I will update this.

 

[martx-5]

I believe that MOSS must of, unfortunately, changed suppliers for their Brake/Clutch master cylinders some time ago. The master cylinder I got from them in the 1980's did not have an adapter - the original "Triumph" steel brake line fit into the master cylinder and sealed just fine. However, the one I got from them in early 2016 had an adapter on it. My finding was that the original "Triumph" steel brake line would only work if you used the adapter. However, if you have for some reason replaced your original 'Triumph" brake line with the new copper/nickel lines from MOSS that use a "Universal Flare" then you do not have to use the adapter.
Moss talks about the Universal Flare in the brake lines section of their catalog (but does not talk about master cylinders, unfortunately).
I wish Moss would explain when you need (or do not need) the adapter in their catalog or with an instruction sheet along with the new master cylinders.
Chuck

This past summer, I put a dual master setup in my TR3. Since I had to go with smaller bore masters for the brakes, I bought
two 5/8" cylinders from Pegasus Racing. They are listed as genuine Girling and they didn't come with the adapters. As you can see in the picture below, I used the adapters with the two brake masters...one with a steel brake line and one with a Moss cupro-nickel line. They were from the original brake and clutch masters that I had bought from Moss when I initially did the restoration. On the clutch master I didn't use an adapter, but it has the cupro-nickel line, which worked OK without it.

Your post got me thinking about this, and I dug out an old master from before I did the resto (without an adapter), looked inside and it had a different seat then a newer one from Moss and Peagsus without the adapter. As it turns out, the outlet of the Girling cylinders being supplied now have a 3/8"-24 (AN3) seat, whereas the adapter and the original cylinders have a 3/8"-24 IF (Inverted Flare) seat. I just got lucky by deciding to use the adapters for the brake masters and having the cupro-nickel line being used where I decided to not use the adapter. Go figure...

As it turns out, I'm going to replace the two 5/8" brake masters with two Girling style masters from Wilwood, as they offer a 1/2" bore size, which will give me a lighter pedal then the two 5/8" sizes I'm now using. They come with the adapters.

 

[Geo Hahn]

I am not sure what to call the flare that is on the brake and clutch lines ... It has a flared back that the captive threaded fitting presses on, the sealing face appears to be a rather rounded affair...

Sounds like a bubble flare.

 

[mastaphixa]

Geo, I would agree, the brake and clutch output lines have bubble flares on them. Is that what came from the factory?

 

[Geo Hahn]

That is my recollection.

BTW - the brake line plugs shown in that photo (from Google) are quite handy and worth making if you have some old fittings around. I always carry one, once had to drive the 700 miles home with the rear brakes disabled when a leaky axle seal caused the brake shoes to come unglued.

Also useful when the line is disconnected for a time during maintenance.

 

[TR-3rg]

This past summer, I put a dual master setup in my TR3. Since I had to go with smaller bore masters for the brakes, I bought
two 5/8" cylinders from Pegasus Racing. They are listed as genuine Girling and they didn't come with the adapters. As you can see in the picture below, I used the adapters with the two brake masters...one with a steel brake line and one with a Moss cupro-nickel line. They were from the original brake and clutch masters that I had bought from Moss when I initially did the restoration. On the clutch master I didn't use an adapter, but it has the cupro-nickel line, which worked OK without it.

Your post got me thinking about this, and I dug out an old master from before I did the resto (without an adapter), looked inside and it had a different seat then a newer one from Moss and Peagsus without the adapter. As it turns out, the outlet of the Girling cylinders being supplied now have a 3/8"-24 (AN3) seat, whereas the adapter and the original cylinders have a 3/8"-24 IF (Inverted Flare) seat. I just got lucky by deciding to use the adapters for the brake masters and having the cupro-nickel line being used where I decided to not use the adapter. Go figure...

As it turns out, I'm going to replace the two 5/8" brake masters with two Girling style masters from Wilwood, as they offer a 1/2" bore size, which will give me a lighter pedal then the two 5/8" sizes I'm now using. They come with the adapters.

View attachment 46512

Hi Martx-5, Can you provide information on the two master cylinder set up? Is a kit or did you fab it yourself? Do you have a proportioning valve in the system or any residual pressure valves? Any cutting of the body tub needed to get them to fit? It might be worth while to post a new thread so I am not hi jacking this one.

Thanks, RG

 

[martx-5]

RG,

I fabbed the setup myself. I don't have any proportioning valves etc. and I didn't have to cut into the body. One of the features of a dual set-up is that you can run a threaded balance bar to bias the brakes. I have one, but haven't installed it yet and may not, as right now the front and rears lock up at just about the same time. When used for racing, the balance bar can be adjusted on the fly with a cable attached to the threaded rod. Dual master set-ups are available from Racetorations...

https://www.racetorations.co.uk/search/triumph-c56/tr3a-c5/dual-master

 

[bobhustead]

A search for bubble flare tools seems to unearth kits with dies only for metric size tubing. I would guess that an SAE clamp would allow use of the metric die, but it is not likely that the bubble was oem.
Bob