May I Have Some Master Cylinder Help Please

[Flashheart]

Hiya Folks,

A while ago I had the standard clutch faff, wouldn't properly engage etc. Looked in the master cylinder resevoir and found black gunge & rubber bits. That will be the seals methinks. Ordered a seal kit and took the master cylinder off today (which was quite easy really).

Disconnected the rod that connects to the clutch pedal and replaced the seal (the one that drips into the footwell). Took the cap apart and replaced the seal. All going well so far but then......

How on earth does the piston (with the spring) within the body of the cast cylinder come out - or doesn't it? I am assuming it comes out and that there is some sort of seal inside as I have about 4 seals left over in the kit, the diameter of 2 of them matches the bore of the cylinder.

Can anybody give me any top tips please as 3 of us have been banging our heads against the wall this evening. It was so bad we just started drinking gin in the street!!!

Best regards, Flash

[itiejim]

It does come out, and that's where the leaking seal is likely to be!

You can sometimes just tap the cylinder against a bench or something and it'll drop out, otherwise you may have to put some air or hydraulic pressure to it. If an air hose won't have it out then I have previously used a grease gun full of gearbox oil - never fails! It helps is you have one which shares the same thread as the master cylinder of course!

[billy no brakes]

Flashheart said:

Hiya Folks,

A while ago I had the standard clutch faff, wouldn't properly engage etc. Looked in the master cylinder resevoir and found black gunge & rubber bits. That will be the seals methinks. Ordered a seal kit and took the master cylinder off today (which was quite easy really).

Disconnected the rod that connects to the clutch pedal and replaced the seal (the one that drips into the footwell). Took the cap apart and replaced the seal. All going well so far but then......

How on earth does the piston (with the spring) within the body of the cast cylinder come out - or doesn't it? I am assuming it comes out and that there is some sort of seal inside as I have about 4 seals left over in the kit, the diameter of 2 of them matches the bore of the cylinder.



Don,t want to the bearer of bad news but it sounds like the seal in the slave cylinder has gone as black gunge and rubber bits normally point to the seal in the slave cylinder has gone which is a gerabox out job to get to it,

Gary

Can anybody give me any top tips please as 3 of us have been banging our heads against the wall this evening. It was so bad we just started drinking gin in the street!!!

Best regards, Flash

[billy no brakes]

oops put my reply in the wrong place best to read through and you will see my reply hope its not slave seal but sounds like it

[Flashheart]

Thanks chaps. I was rather hoping it wasn't the slave hence trying the master first.

Itiejim, thanks for that. I will try pressure/tapping it but must admit that I'm not sure how successful it will be as the plunger fits up tight against what looks like an aluminium ring within the body of the cylinder. This ring has a diameter less than that of the plunger so the plunger doesn't seem to be able to come out. I'll try a bit of brute force and ignorance later today.

Regards

Flash

[itiejim]

You may find you need to remove a C clip or circlip of some sort.

[supersix]

Flashheart said:

Itiejim, thanks for that. I will try pressure/tapping it but must admit that I'm not sure how successful it will be as the plunger fits up tight against what looks like an aluminium ring within the body of the cylinder. This ring has a diameter less than that of the plunger so the plunger doesn't seem to be able to come out. I'll try a bit of brute force and ignorance later

Not done this on a cerb, but there's always a circlip that the piston rests against when there's no pressure on the pedal. You'll often find you need to found a way of pushing the piston in a little while releasing the circlip.

Anyway, seconded itiejim's suggestion of using air to pop the piston - they can sometimes be a bugger to get the seals past the circlip channel, even with the spring pressure. If you've got any suitable nipples handy (easy now!) then drop one in a little - not fully in - and get a foot pump onto it. Don't point it at the car while you do this