Master Cylinder failing after bleeding

[getunder]

In a lifetime of motoring and tinkering with them I have had 2 master cylinders fail just after bleeding. I put this down to the fact that when bleeding you use full strokes of the piston and with no resistance the piston travels further than the polished bit into unused grotty territory with corrosion etc., which finishes off a probably worn rubber seal. What to do is up to you but one moral is don't do a brake bleed on an very old vehicle just before an important trip

[Red Westie]

That's why professionals use pressure bleeders....basically a drum with wheels that you fill with DOT4 and is connected to the resevoir with an adapter, the bottle is then pressurised to force fluid into the resevoir, all you have to do then is slacken off each nipple in turn and bleed. No pumping, no chance of seal damage.
Martin

[asahartz]

The Eazibleed is the home mechanic's version. However there are some vehicles it just won't work for; my wife drives a Toyota Previa which has a rubber cap. You just can't get a cap that will fit the Eazibleed without being blown off by the pressure on that car.

But it does work OK for my Minis and T25, so it's good enough!

[Ian Hulley]

Eazibleed is great for the brakes and clutch slave cylinder (if you need to force bleed it), for the clutch master though gentle tapping and a break for a cup of coffee worked for me.

Ian.