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MG TD TF 1500 - Brake fluid seeping

I have all new wheel cylinders of my car. The front cylinders are seeping brake fluid from the banjo bolts on each front wheel. I am using DOT 5 fluid. I installed Moss copper washers in the entire system and there are no other locations with leaks or seeping. I replaced the copper washers form Moss with soft copper ones but the seeping continues. I'd like to try bonded seal washers (washers with an inner soft ring) but I don't know if they will deteriorate with DOT 5 fluid. I've asked a few sellers but haven't gotten a reply yet. Any suggestions?
Thanks

Tim
TD12524
TW Burchfield

Tim,

Did you heat the copper washers to red hot to anneal them and then polish them flat on a glass plate? Also, banjo bolts must be very tight. Being gentle is not the answer. The above three steps worked for me without problems. Good luck!

Jim Haskins
1953 TD
J. M. Haskins

Tim,
I had the same problem when I installed new wheel cylinders on all 4 wheels on my TF and used Dot 5 fluid. Research on the subject, on this sites archives indicated that silicon fluid is more viscous (hope that's the right term) than regular Dot 3 fluid and more prone to leak.
The solution - believe this or not, was every day tighten the fittings ever so much. I did it for 2 or 3 days, thinking I would surely strip the threads on the fittings but that never happened. The leaks stopped and it' has not leaked since. That was over 2 years ago.
Good luck and check the archives for specifics.
Mark Stolzenburg
Chesterfield, MO
TF8263
Mark Stolzenburg

Jim, I've never did that with copper washers and never had leaks before (MGB, TR3). But I'll try anything.

Mark, thanks. I have been tightening them occasionally and like you I'm afraid of snapping something off. I looked in the archives for every iteration of brake line seeping, leaking and fluid loss but couldn't find anything. Could you give me the secret phrase that unlocks the archives on this subject?

Thank guys.
Tim
TW Burchfield

Agree with all above. Also take a close look at the sealing faces on the new cylinders and banjos. They need to be really smooth w/ no machining marks or anything on them. No clue how the factory finish is, even a tiny scratch will make them leak. George
George Butz

I agree with Jim. The best solution to banjo bolt leaks is to polish the washers to a mirror finish and polish the banjo faces as well.
I discovered this years ago working on a biodiesel motorcycle. Biodiesel is a remarkable penetrant much like WD40 and can seep through most washers and hose connections. I learned to grind everything on a slow wet grinder and polish every face to a mirror finish, and once I did that I never had any leaks.
I did the same (didn't need a wet grinder tho) with my banjo brake assemblies and the banjo oil connections on my oil filter assy for my 51 TD and it's always resulted in perfect connections.
Geoffrey M Baker

I found my leaks to be from not tightening the bleeder valves enough.
I used the type with the internal check valve and the threads are coated with a sealant. You need to be very aggressive in tightening them, the valves tat is along wit the banjo bolts.

Jim B.
JA Benjamin

Tim,
The thread you want is "Silicon (Dot 5) Leaks", dated 02 June 2013. It was my inquiry back when I had the problem. Dave Braun recommended to keep tightening the fittings. I did this each day for 2 or 3 days and it finally stopped the leaks. I thought I would strip the fitting and it never seemed like any of the fittings moved much, but it worked without stripping anything. I was careful not to bend the copper lines on the fronts that connect the two wheel cylinders. All I can tell you is that it worked
Mark Stolzenburg
Chesterfield, MO
TF 8263
Mark Stolzenburg

Thanks everyone.

Mark, thanks. I'll (cautiously) give it a try. First I'm going to disassemble the front lines and make sure the banjos are perfectly smooth. Your advice on tightening the bolts reminds me of my dad, a life long mechanic. When someone would ask him how tight to turn a bolt he'd say, "As tight as you can get it and two more turns."

Tim
TD12524
TW Burchfield

Tim
Its worth the trouble . 9 years and 14,000 miles now and no trouble from my brakes at all with DOT 5. I also confirm the above advice .
Keep at it.
Cheers !
Keith
K. McKenzie

To test bonded seal washers immerse in Dot5 for several days and observe the results.

"Apprentice method for bolt tightening, tighten until you feel the thread stretch then back of 2 flats."
G Evans

Heating the copper washers to cherry red works unless (prior to heating) you see any pitting or scoring. I recently removed the banjo fitting that feeds oil into the block, and after 65 years it actually had deteriorated to the point it had to be replaced. I never polish the washer after heating. You do not need to heat new washers. You should clean up and perhaps polish the fitting where the copper washer will be against, if possible.

Banjo fittings on the brakes use copper washers. Banjo fittings on the fuel system use a combination of fibre and copper washers. Parts catalogs are a god way to keep that straight.
N Tesla

This thread was discussed between 23/09/2015 and 05/10/2015

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