Fornt master cylinder woes. Please help!

[teriyakimonkey]

I managed to accidently pump out a piston the other day so I've decided to take the calipers off andsort them out.

Master cylinder was run dry. Today I put the calipers back on to pump out the remaining pistons. Put brakefluid in and nothing.

Lots moremessing around and I now have the master cylinder in the sink. I can blow up the outlet with a bit of pressure and it comes out of the reservoir. When I blow and push the piston it blocks it, as I'd expect. However if I push the piston it won't push anything, not brake fluid, not water and not air (I think).

What the **** is going on?! It was fine a couple of days ago to push one of the pistons all the way out and the other three partially. I've tried lots and lots of brake cleaner and hot water but nothing's clearing it, if it is indeed gunked up.

Help me. Please.

[StumpyFingers]

You may need to service the master as well.

[teriyakimonkey]

Why would it happen though? Has some gunge clogged it up because I let it run dry?

[StumpyFingers]

Why would it happen though? Has some gunge clogged it up because I let it run dry?

That is possible.
The thing with brakes is the design is simple but parts are only as good as they are, (i.e. prone to fail at inopportune moments ) therefore anything could have caused it.

[teriyakimonkey]

I've now got circlip pliers and have taken the MC apart.

Here's my one followed by a pic of the rebuild kit.





Mine seems to be in good condition but are the seals in the right place and do they look the right way round? I'm a bit confused why the rebuid kit has a cup without a hole in it?

[StumpyFingers]

I've now got circlip pliers and have taken the MC apart.

Here's my one followed by a pic of the rebuild kit.





Mine seems to be in good condition but are the seals in the right place and do they look the right way round? I'm a bit confused why the rebuid kit has a cup without a hole in it?

The "cup without a hole in it" is the boot it fits at the lever end.

[piguglyshandydrinker]

Once you have air in the system, it does take an age - lots of pumping, to re-prime it, doesn't mean that it needs a rebuild.

Phil

[teriyakimonkey]

Too right piggy. THat was my problem. Too much haste. GOt the pistons out now.

TIme to buy a one way valve bleeder doobrie methinks.

Thanks all.