Land rover 90 Brakes

The brakes on my 90, when i bought it were non-existent. The master cylinder was gone, so the pedal went straight to the floor.
A restoration project was then decided upon and for the last 4 months i have been doing work on it.
So, i am at that stage where i can see the finish line. The master cylinder has been replaced, (That could be part of the issue). The brakes work really good. unfortunately, after a while the rear brakes (Drums) just start locking up to the point where 3rd can't take the strain.
The drums also feel really warm.
To fix the issue, i have to release fluid from one of the drums. Then, the system rolls freely again. I'm guessing it's a buildup of fluid in the slave cylinders or something.
Can anyone help?

Thanks

try pulling the vac hose from servo next time to release any vacuum and see if that frees brakes if it does servo /master cylinder rod needs shortening

jamesmartin said:

try pulling the vac hose from servo next time to release any vacuum and see if that frees brakes if it does servo /master cylinder rod needs shortening

Click to expand...

Okay, i think i might have them, finally, adjusted properly. Thank you, that was the problem. The master cylinder was pushing fluid to the cylinders, then was not allowing the fluid to come back, thus locking them.

Thanks again!