Helping friend bring his 76 Buick out of hibernation a little early to make sure all systems are go, got it fired up with minimal trouble, hop in to check for brake pedal, to the floor it goes. I sort of expected this, when he bought it last year it looked like it had the original brake fluid in it, we flushed the hell out of it but I warned him it would probably need a master soon, at minimum. We're starting there and ordered a Delco replacement.
So now it's time for that job, and I'm not sure the best plan of attack to avoid inevitable drips of DOT 3 melting any holes in the single stage paint. Cover the whole DS corner in plastic drop cloth? I figure I can suck out a lot fluid from the reservoir before removing any lines, but there will still be drips and I always make a mess when working with those old open top masters.
We plan on reverse bleeding it though the bleeders(calipers and wheel cylinders are definitely pretty clean) after installing it dry to avoid the mess of installing a dripping bench bled master.
Spray water over the drips to "neutralize" them so they won't eat the paint. Maybe have a friend stand by with a super-soaker.
Suck out the fluid before removing it, then wrap it in a rag or a newspaper or something similar so it doesn't drip on the fender. Another way would be to slip a plastic bag over it. It's not that difficult, just be careful. Don't forget to bench bleed the new master cylinder before installing it.
In reply to stuart in mn:
Good idea on bag, I'll bring a gallon ziplock.
No bench to bench bleed, going to hit TSC, get a bigass syringe and some tubing, and reverse bleed it on the car like a motorcycle.
I don't think I'd reverse bleed that car. If the fluid leaked out in storage you have a leake somewhere and I'd want any debris from that leak heading away from the master towards an end. I'd also replace every hose and get a few good pumps through the metal lines with the rubber hoses disconnected before I put the new hoses on just in case any big shrapnel is in there. When fluid is clean at that point put on new hoses and finish out unit you get pedal back.
Saving paint isn't as important as being able to stop that boat reliably
Do the above. If there is any rust in the metal lines it will either go into the MC if you reverse bleed or into the wheel cyl. or calipers if you bleed without flushing the lines first. DO replace the rubber lines. I would bet they won't cost that much and they are most likely OEM so old, hard, and brittle.
chances are the rubbers are $5 each or less from rock auto.
you don't really need a bench with a vise to "bench bleed" - it just makes it easier.
Just wipe it up.
Unless you let sit there for a long time it's not really going to do anything. It isn't thermite.
bench bleed on car as follows:
- bolt MC to booster
- bend up some spare hard lines that loop back from the outlet ports into the reservoir
- fill reservoir
- set up a mirror so you can see into reservoir from drivers seat
- pump pedal until no more bubbles
- win
In reply to AngryCorvair:
This one (Skyhawk, the Monza badge job) has the master raked back at enough angle that I think we'd need to jack up the rear to do it on car, but it is an option.
Or I could rig up some short lines to do this on car with a cheap syringe https://www.youtube.com/watch?v=IHLi4tyFcJo and avoid all the inevitable splashing that goes with touching the brake pedal on an open top master cylinder.
