Master Cylinder Removal

[John L.]

I plan to remove a 50 year old master cylinder and have it sleeved. Does the following procedure make sense?: 1) Remove brake fluid from it and disconnect from brake line.
2) Cover end of brake line.
3) Send out for sleeving.
4) Upon return, bench bleed it, reinstall and fill with barke fluid.

Will there be a need to bleed the sytem following installation since I will not be disturbing the brake fluid in the brake lines? This is my first doing this.

Thanks

[Edward J.]

Re: Master Cylinder Removal

John, it would only make sense to flush out the old brake fluid in system since your rebuilding the master cylinder ,You'll want to remove any moisture in the system that maybe there. Bench bleeding the rebuilt master is a good idea this will help when bleeding the rest of the system.(makes life easier)

Before shipping I would remove fluid and wrap in a zip lock bag.

[Paul S.]

Re: Master Cylinder Removal

I'm not sure you'd be able to keep air from being in the brake lines effectively. When I replaced my MC on my 67 (which went belly up after I flushed the brake fluid) I bench bled the new MC, installed, and then bled each caliper. There was air introduced by having the lines off, and mine were off for a short time. Don't know how you could manage to keep air out for weeks while the MC is off being re-sleeved.

By the way, bench bleeding is essential in my opinion-I'd hate to try working any trapped air in the MC all the way through the brake system. While it can be done mounted on the car, it's a lot easier clamped in a vice on the bench; tie off the bench bleeding tubes; carry to car; mount; then connect lines. Almost no fluid ran out when I unscrewed the bench bleeding fittings and put the brake line in place. Not a mess at all.

[Jeffrey S.]

Re: Master Cylinder Removal

John,
Just remember that conventional brake fluid is the best paint remover known to man (don't ask me how I know). Cover EVERYTHING with plastic and anything else you can think of to protect your paint. Once I remove a line from the mc I use a plastic plug and screw it into the open port. After bench bleeding I plug up the port until the unit is put on the studs and the nuts are started on the studs. Leave them loose so you can move the mc around a little to facilitate starting the lines in the ports. It's always advisable to bleed the system anytime it is opened up.
Jeff

[John F.]

Re: Master Cylinder Removal

Agree with guys above. There is always a little air in there. I also went with DOT-5.
John F