Brake Systems Canniablelising Itself (SOLVED)

I had noticed some drops of fluid on the swingarm. I went in for a closer look and noticed a major issue on the rear brake master cylinder. Note....these were all fresh parts. It was corroded like a positive battery terminal does. The surface of the master cylinder was lifted, powdery and soft. I really haven’t seen this before but have several ideas to why it happened, wanted to see what the forum thought first so not to bias the answers. Your help would be greatly appreciated.

Thanks, Spencer

Was the cap on tight? looks like fluid got under the paint and went to town on it.
I think a lot of the white stuff on brake line is from the fluid eating the plastic coating of the line :sick:

The cap was tight, dosent mean it wasent leaking? fluid was getting out somewhere...but the white stuff was on 100% metal no plastic around.

Check the banjo bolt fittings,I think most of them have some sort of clear coating that protects them from rubbing.
Check with z1 for a new seal for the lid,and also for between the resevoir and mc body itself.
Yet another reason I like the dot 5 fluid,it doesnt hurt paint if it leaks.

brake fluid and paint are mortal enemies with brake fluid being the ultimte winner everytime


I painted a front master cylinder put it back on weeks later bled the brakes put the top on
wiped it off rode the bike once about 4 miles

3 months later (decided to sell the bike) uncovered it and the master cylinder was similar to yours

I did use dot 5 , if you rem the thread I started...on the advise of the forum, and suffered no damage to the bike but the master cylinder. I will reinstall in an unpainted form on the rebuild.

I have it soaking in carb cleaner now...going to start over. The master cylinder cleaned up fine with soap and water...inspected it and tossed it into the cleaner.

The leak seems to have come from the plastic cut and where it meets the master....need to get a new gasket for this area.

Dot 5 fluid shouldnt have done that to paint :blink:
Ive dumped it on paint many times without an issue like that,dot 3 on the other hand definately reacts like that in my experiance

Did you soak it in carb cleaner the last time you rebuilt it,how did you clean it after soaking the last time?

Soaked

Make sure to soak/scrub in simple green or something like that to get all the carb cleaner out of the aluminum before painting again.

Ok, I have that...will do...thanks.

The more I get into this the more Im considering that electrolysis is the factor causing this. With dot 5 used and brand new chrome items finish chewed off the bango and hose connector....and the damage being located at the bango where power is....I really am leaning this way.

If brake fluid is the cause...then why didnt it damage the battery box, swingarm and other painted items the fluid covered and had splashed on....they all look fine after cleaning and had no affects of brake fluid getting on them?

just the bango, hose fitting and master were affected in this certin area.