Just Bled and replaced my brake fluid in the ol 71 Super Beetle.
Used Dot 4. Within a day, all the blue flexible lines from resouviour leaking like mad along their length .... and master cylinder dumping fluid from the rear seal ...... read ..... had it. WADDIDIDOWRONG?????!!!!!

Maybe I shudda used Dot something else. The old fluid was really old and stuffed and dark and yuk ....... but at least it stopped the car without escaping to freedom

Now have to replace the master cylinder so .... any ideas .... did I put the wrong fluid in?

don't think so
dot 4 I think is the stuff
maybe just super old shite fluid giving a spongee pedal n coupled with old half perished lines etc the new stuff maybe just was too much for the old ones
see what others reckon

" and master cylinder dumping fluid from the rear seal"

If you bled it by "fully depressing" the brake pedal the seals inside pass over pitted crappy area and chew out.
As for the lines,probably just old,maybe better failing now than during an emergency stop.

nuthing wrong with the brake fluid the probleem is as per above its just disturbed all the crap that was in the system and torn the seals

you can use some tie wire around the ends on the blue filler lines to secure it will hold them in place

Agree with 'h' lines etc probably already stuffed and with new fluid in there would be more pressure on lines etc, causing them to give up. Happened to me when redoing a hydraulic clutch.

thanks you guys.
New brake fluid has not attempted escape from new hoses and masta cylinder.