TR2/3/3A Moss ClassicGold mastrer Cylinder

Working on the car today I noticed clutch master leaking into bellows.My first Classic gold MC failed at 2yrs 4k miles not covered on warranty.
Over this past winter I purchased and installed another new Cassic Gold MC and this one has now failed a 2K miles.All linkage is straight and adjusted .Upon dissasemebly of the first failed unit I noticed the design has only one main seal on the piston with no guide or secondary seal.I believe the original had two seals on the piston.The inside aluminum bore is worn away by the front of piston dragging on the bore,Seal is on rear foot valve end.Brake Mc is ok and I suspect its because it does not see a long stroke.
Is anyone else having these issues?
Who makes a better MC?
Am I right about the originals having 2 seals,not including the foot valve assembly? I Gave my original to a forum member because I had bought all new.
Can the original type be purchased without a core?
Hoping to resolve before 9/8 as I was planning 250Mile trip to Watkins Glenn.
Thanks
ps,will call Moss in the AM
Thanks
Tom

Early originals did have a second seal on the piston, but it was officially deleted by Girling. They used to pack a note with the rebuild kits to remove the old seal and leave the groove empty.

TFB said:

...Who makes a better MC?...

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I haven't used them (mine are old but still good) but I think Pegasus offers what they state are Girling master cylinders:

https://www.pegasusautoracing.com/productselection.asp?Product=3502

You could also check out Wilwood. ISTR hearing that they offer Girling pattern single circuit master cylinders in various bore sizes.
https://www.wilwood.com/MasterCylin...roup=Compact Remote Reservoir Master Cylinder

Thanks for the links.I talked to Moss and they are sending a new one as the warranty is 2yrs.As to the Girling from Pegasus or the Wildwood all seam almost exactly the same externaly except the name and I wonder how different they are internally or if they all come from the same source.
For instance the bellows with rubber band,which has to be slipped on after mounting because its bigger dia. than original and doesn't fit through the mount hole with it on seems the same on all three.
Anyway after a closer exam of the first failed unit it looks like the piston edge was sharp enough and had enough clearance to mis align and to scrape the bore .
The very corner of the piston is worn shiny.
So I think when the replacement comes I will take it apart and break the edge and polish the front corner of the piston.Hopefully the next one will last or its one of the Linked units next time.
Thanks

Not surprised since they usually are, but glad to hear Moss was good about it.

Let us know how this goes.

Question: What failed? A bad seal? Are those seals replaceable with a rebuild kit originally intended for the original Girling cylinder (i.e., an SP1963 kit for the 5/8" bore)? EDIT: Oops, I missed your follow-up post! I would be a bit leery of actually "polishing" the new internals. I don't see a problem, though, with your examining same and contacting the supplier regarding any problem you see!

Andrew Mace said:

Question: What failed? A bad seal? Are those seals replaceable with a rebuild kit originally intended for the original Girling cylinder (i.e., an SP1963 kit for the 5/8" bore)? EDIT: Oops, I missed your follow-up post! I would be a bit leery of actually "polishing" the new internals. I don't see a problem, though, with your examining same and contacting the supplier regarding any problem you see!

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Thanks Andrew.
If you saw the cylinder and bore I think you would agree that either the piston is to loose or leading edge of the piston to sharp.I would only smooth or polish that edge.
The bore damage makes the cylinder not a rebuild candidate.BTW they are .75,not sure what originals were.
Thanks
Tom

I noticed my Master cylinder started dripping out the boot again.Curious if I am the only one who is having Clutch master cylinder leaks with the Moss classic MC and dot 5.This last replacement lasted only about 3k miles.
I guess
I will start by calling Moss on Monday and see if they are still using same design.

Tom

I have had similar problems with Classic Gold master cylinders, as well as slave cylinders, regardless of the vender.
I will check out the links shared here the next time one of the Classic Gold units begins to leak.

TFB said:

I noticed my Master cylinder started dripping out the boot again.Curious if I am the only one who is having Clutch master cylinder leaks with the Moss classic MC and dot 5.This last replacement lasted only about 3k miles.
I guess
I will start by calling Moss on Monday and see if they are still using same design.

Tom

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I don't know, but you make me feel better about having tossed a Moss Gold MC last week. I was going through old parts and decided it was not worth the effort of re-gifting. No guilt now...Thanks!

I thought I remembered something from a few years back about that brand so I googled:
https://thisweekattheshop.com/?p=535

That was even 5 years before this necro-thread

Frank Angelini found that problem when he was restoring his 3A and alerted Moss to the problem. I'm glad he did but sorry the issues with that manufacturer persist.

During my TR3 restoration, if it was possible original parts were used. Many trips were made to Marvin's place searching for the correct stuff. To keep the original brake and clutch MC, I had SS sleeves installed by Brake & Equipment Warehouse, Minneapolis, MN. It wasn't cheap, $75 each including shipping, but no issues since April, 2010. I also used TRF rebuild kits and DOT 5 fluid.

Yes I remember the recall.Moss recalled my cylinders and even gave a $150 to cover labor to remove.I had not got the car on the road yet.Then the recalled
replacement units and now 2 units after after failed,3 total in 9500 miles.
While I have 2 original cores,I gave my internals to a forum member who was going original and I figured I would never need them as I was going all new.
I did contacted Apple Hyd. about resleeving,but I may need to find some internals as their site seems to indicate they resleeve and you rebuild.This may not work with the Moss internals because I think the piston clearance is sloppy compared to the originals.
As Randall mentioned Girling also went to a single seal,but I think this must have only worked with better clearances and maybe dot 3 being more lubrous than dot 5.Waiting to hear from Apple and calling Moss later.
Also As I look at the offerings from all the available suppliers I
think they must all come from the same source.Even the Willwood seems exactly the same externally.The exception seems to be the Pegasus which has an original style boot,no rubber band,also the most expensive at $124 butI may take a chance.
But I still suspect the "exclusive" part is they put you name on it--Willwood or Girling.
Tom

update:Moss is sending a replacement.Seems I paid for the last one in 10/15,so the one I got as replacement in 8/16 is still coveerd. They said its not the same part number and is not the same,so hoping for better results this time.
Apple got back to me and they offer complete resleeve and new internals for about 145 with a week turnaround,so would be about 2 weeks to get in my hands.I will hold off until I see the new Moss unit.

Positives1.this is the only problem I have had with car in 4 seasons and 9k+miles
2.I made John feel better about having thrown his away.
Tom

TFB said:

...
Even the Willwood seems exactly the same externally.The exception seems to be the Pegasus which has an original style boot,no rubber band,also the most expensive at $124 butI may take a chance.
But I still suspect the "exclusive" part is they put you name on it--Willwood or Girling.
Tom

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I bought two of the Pegasus Girling cylinders in 5/8" size for the dual master set-up on my TR3. When Wilwood came out with the Girling style cylinders in 1/2" size, I bought two of those to replace the Pegasus ones as the braking forces were a bit high with the two 5/8" cylinders. In comparison, externally, the cylinders have a lot of differences, including the names "Girling" or "Wilwood" cast into the sides. Neither came with an original non-accordian style short boot. The boots on the Pegasus Girling units did come with a fat rubber band, but they worked fine without them. Also, the Wilwoods are painted black. They definitely are not made by the same manufacturers. With the exception of the boot, the Pegagsus "Girling" is the same externally as the originals. Also, the original style short boot will fit it.

I can't vouch for the longevity of either master. The Pegasus Girlings were only on for about three years (maybe 6000-7000 miles) and the Wilwoods have only been on since last April. I use Dot 4 fluid. If I was interested in originality and didn't want to re-sleeve, I'd buy the Pegasus Girlings and put the short boots on them.

Thanks for reply Art.After my post I noticed the Pegasus boot in drawing appeared original but the pic shows same bellows and rubber band.
I think the brake cylinders last longer because of the short stroke and the clutch gets used way more than the brakes.
If the next unit fails I think I am going with the Apple rebuild,only a little more than Pegasus.
BTW,I am sure Moss,and me, would have rather had the product they distribute from their vendor be problem free but from the way they handled the recall to standing behind the warranty I am glad they seem committed to getting it right and didn't just drop the cylinders from their product line.
Thanks
Tom