I have got a 98 fatboy with performance machine foward controls.

The pm rear brake master sprung a leak and the rear brakes are out of action.

I took the master off to install a rebuild kit and i noticed the inside of the lid has chrome flaking off and it was all over the rubber dust cover. 

I'm going to go with plan a, that the chrome flakes got into the brake fluid and wrecked the seals causing the leak.

The master was empty when I took the lid off, but I want to know if I can get away with replacing the lid and flushing the system, or do i need a new master?

Thanks.

Do you know exactly where it is leaking from?

I can see why chrome flakes would be on top of the rubber but how would they get under it?

Maybe you could flush it all out, re-bleed till the brake works, make sure the outside surfaces are all fluid free and watch closely next time you ride it too see where the blazers the fluid is going.

Yeah, it's worth a try. I figure it needs new seals. 

When I took it off there was crap up inside the rubber boot around the push rod and the spring had a bit of surface rust. 

I'll give it a flush and a rebuild kit and see if it sorts it out. 

Thanks.

clean hone & inspect with a new kit as min ass with rubber grease only . also rear caliper strip & clean reass with rubber grease  + check disc for dishing with a straight edge on da outside full lenght of disc & look with a touch from behind & see if any light comes thru , fatboys are bad for dishing disc rotors

It's funny you say it's the solid wheels that cause this problem , as I've had it happen with spoke wheels on the rear and
In my time on Harley's I would say you do tend to use more back brake than front as the front does not stop just slows you down a bit Compered to riding jap bikes which you tend to use 70% f. 30%r. Harley evos seem the other way to me with single disc and Oem brakes

with any forward controls brings bad riding habits too big on da back brake ,  & not servicing the brake fluid enough & pushing da caliper piston back to clean its path enough etc , 

Yep I would agree with That in regards to a bit more matnence seeing the master is a lot closer to the road / water spray dirt and grime on a hd

I have factory 3" extended forwards on my softail and the master cylinder is directly behind the rectifier and very close to the front header, the hose to the rear runs close to the rear pipe along frame. could there be an evaporation issue from heat, sorry deviate but while where' on the subject.

keeping it cool is always good if ya can but these are not racing bike's , if ya don't use da front brake enough you will cook da rear , & da front tyre will never wear out once its goe's hard with age

A flush and bleed with new fluid seems to have sorted it out.

Thanks for the tips everyone.