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MG TD TF 1500 - master cylinder disassembly?

Hello again,

My '50 TD has a Lockeed master cylinder now on my bench. I'm trying ti take it apart to determine if it needs any new parts, honing, or maybe rebuild by White Post or replacement. The shaft & circlip were easily removed but how do you get that washer or whatever it is out so you can pull the internal parts? I assume they come out the front end? I've searched the archives but can't find the specifics on how to take it apart.

Thanks,
Ed
efh Haskell

ed, page M.4 and M.5 of the mg td workshop book have the exploded view. yes, it appears you are correct (its been a few years since i did mine) after the circlip is removed the guts come out the front. it also appear a small brass drift, inserted through the brake fluid line port, could be used to persuade stubborn parts out the front. regards, tom
tom peterson

Just yesterday I removed the circlip and washer, pushed the piston down into the bore 1/2" deeper, cleaned out the corrosion and debris with a Scotchbrite pad, gave it a bit of WD-40 as lubrication, held a rag over the open end, and a quick shot of compressed air popped it right out. It's the junk at the mouth of the m/c that stops everything from coming out easily, as though there were a ridge there.

If you try to poke in from the end with a drift you can damage the metal valve body.

Tom
t lange

Thanks Tom for the reference but I still can't get it out.

Just to clarify, it's called the "Stop-Piston" in the WSM diagram and it's the thing the screwdriver is pointing to in the photo below. I guess it's rusted in place?? At this point I can't get the fluid line in rear to budge either and I'm afraid a brass drift would destroy what's inside. I just want to "inspect" the guts today.

Any other ideas?


efh Haskell

The spring in the m/c is about 3" long, so the piston can push down a good deal. Once the circlip is out put a dowel in the piston and tap it with a hammer to push it down a bit. Then lever out the stop, clean as above, and go from there. Call if I can help.

Tom 207-288-0978
t lange

Put it in an old coffee can Ed. Fill it up with water and put that in another pan and fill with water and bring the whole mess to a boil for about 30 minutes. Should come apart after that. Blow dry everything with your new fancy compressor.
LaVerne Downey

Thanks guys, I got it out! A squirt in liquid wrench, wait 1/2 hour, pry it out easily. (I know, clean that stuff out of there before re-assembly! I will.)

Now that it's apart, the pieces look "pretty good" to me. Rubber is soft & flexible, no visible tears etc. Bore seems very smooth to the touch using little pinky (no DRE jokes or otherwise please:)

Since I have the newer "concave washer" part, the WSM would incidate I have one of the "later model" Lockheed cylinders. That said, can you tell which Moss rebuild kit I would need if I went that way? I'm not sure-maybe just tired.

Or would you just spend $159 min. and get a whole new cylinder from Moss or White Post? (I've spent plenty this month at Moss, trust me! Would rather just put it back together and move on, but "Safety Fast"...)

Your opinions are always welcome here!
Ed


efh Haskell

My feeling is that you should rebuild the m/c no matter what; it's small economy for peace of mind. As to replacing the m/c, I would not; unless there is considerable corrosion in the bore where the cup is, there is nothing wrong with it. At the very worst, if there is mahjor corrosion, have it sleeved in brass (Phil Marino) or, even better, stainless (Mark Frappier). Glad it came apart so easily. Once done, always remembered.

Tom
t lange

Ed,

You need rebuild kit 180-910. I agree with my friend Tom, rebuild it with a new kit. Use silicon grease to rebuild, or silicon fluid, if you are intending to go that route on reassembly.

I'm using the same MC that came in my car. I've rebuilt it three times in 25 years.

warmly,
dave
Dave Braun

Ed - I'm with Tom and Dave, once it's apart, hone the cylinder (even if only slightly) and replace the rubber components - it's cheap and easy (you've already done the hard part) and good insurance . Cheers - Dave
David DuBois

This thread was discussed between 17/04/2010 and 18/04/2010

MG TD TF 1500 index

This thread is from the archive. The Live MG TD TF 1500 BBS is active now.