TR2/3/3A Defective master cylinders Tr3

[mctriumph]

Having a business that regularly serves the needs of Triumph owners(and me too) I have had trouble getting
a quality replacement master cylinder from my regular suppliers. The symptom is that it is very nearly impossible to bleed
the air from the system regardless of time spent or the expertise of the tech performing the job.
Disassembly of the new units reveals that the tiny waffle washer in the end valve of the plunger is not there. There was a good
reason the factory had it in there in the first place. Some kid in Taiwan is not putting them in and these (IMHO) defective
units are all over and the distributers say they are just fine if you only get some engineers to bench bleed and work for 3 and a half days
eventually most of the air is gone.........I call DINGO ON THIS! The cost of this tiny washer is miniscule and the time I have personally spent
on just one master, trying in vain to do a job that should take minutes, is sad.
If you have to buy a new master for a tr3, get a kit or cannibalize the old one to get the waffle washer or you will wish you had.
MD(MAD DOG)

 

[mctriumph]

Just completed my third cyl re-build on a "new" AM cylinder . Found massive amounts of metal shavings and grit. NO
washer, which by the way is still included in the kit from TRF....
So far in my experience the AM master cylinders are coming from the factory in non usable condition. Re-build before
installation or wish you had done so.
MD(MAD DOG)

 

[CJD]

Another bad repro part hits the shelves!

 

[71TR6]

Thanks for the information- this is very timely since I just purchased a couple of cylinders and will take them apart to check on them. Do you have any pictures of the waffle washer and where it is supposed to be?

Ron

 

[Geo Hahn]

It is number 12 in this diagram:

 

[Geo Hahn]

Some rebuild kits come with one...

And some don't:

 

[Graham H]

I had the same problem 10 years ago finally gave up and got the original rebuilt. Just for interest will take the non-genuine one apart and check it out.

Graham

 

[martx-5]

I've bought master cylinders from Pegasus and Wilwood. Not cheap, but no problems either. I believe I may of had to change the push rod because the length was different. The design of the boot is different, but that can be swapped also, at least on the Girling unit. I haven't tried it on the Wilwood.

Pegasus Girling Master

Wilwood Master

 

[71TR6]

This has been a very helpful thread so for everyone's FYI, I checked the set of AM cylinders I got from Rimmer as well as a rebuild kit. The kit did come with the wave spring. I disassembled the AM cylinders to see what the difference is from the originals. The wave spring was replaced with a coil spring in the AM assembly and I also noticed that the piston does not have the secondary seal (#18 in the image). Sadly, the rebuild kit does not have the secondary seal so I'll probably just fit a nitrile oring. I'm going to clean up and use the originals and keep the AM one as a backup for now.

Ron

Here's an image showing the two- the top one is AM, bottom is original.

 

[Geo Hahn]

...Sadly, the rebuild kit does not have the secondary seal so I'll probably just fit a nitrile oring.

You may find there is more to that seal than an o-ring can replace. Some are a little cap, others are a ring with a lip and a flat forward edge.

 

[mrv8q]

Doing mine now, been a while since I last did the master cylinder seals, 15 years or so! Is it ok to use a dab of anti-seize on the threads of the master cylinders and the reservoir? I was surprised how tight they were...

 

[mrv8q]

I’m reassembling now, gotta say the #13 part, referencing Geo’s part diagram above, is looking pretty tired after 60+ years. It feels like it is made out of aluminum? The screwdriver is pointing to it below. Are these available anywhere separately?

 

[TFB]

If it hasnt been covered yet the easy way to check the mc before install is to blow in the inlet,line to reservoir, and air should come out the outlet.
Then as your blowing press the plunger in,hopefully no more than about 1/16 and the hole should seal allowing no air to blow thru.
If it doesnt pass this test somethings wrong.
Tom

 

[mrv8q]

Thanks, Tom. Both MCs are working as they should. I would love to have newer parts for the MCs, besides the rubber seals. Except for a new MC, I’m guessing the parts are not available.