Technical Clutch Master?

[BikeDoc]

I don't suppose anyone knows the Bore size of the Clutch Master Cylinder?
Think I might need to replace the seal(s) on mine, but don't want to fork out £50+ for the privilege if I can help it.

Might be able to source a seal kit from another unit if I know the size.

 

[glowplug]

I have a brand new one I bought as a spare. I'll measure and let you know, but having done the job I would recommend using the tried and tested method.

 

[portland_bill]

If it is a plastic cylinder, like many these days, replacement seals may be difficult to source.
On my Panda, the plastic bore wore, causing the piston to squeak and stick, not fixable.

Seems to be one size fits all, petrol and diesel.
Fiat part number 51775173
Valeo 804877

Good hunting.

 

[BikeDoc]

From what I've read Bill, it's a Plastic Cylinder, but with a Metal liner.

Glowplug, I'm planning on stripping the innards out in-situ and replacing the Seal (I think that's what you meant), I don't fancy forking out for a complete unit just to get a seal.

 

[glowplug]

Yes that is exactly what I was referring to, however I am with you in concept.

Here is what you want

Rear seal (closest to your foot) 16.5 x 9 mm
Front seal 16.5 x 6.5

Measured using a vernier AND using the old piston and seals that came out my car so I would probably go slightly larger on the OD to account for inaccuracy on the vernier and wear on the old seals. ID is unlikely to have changed.

 

[BikeDoc]

Thanks GP.
I've not tried bleeding it yet, but have just finished bleeding the Brakes all-round, flushing fresh Fluid through, I'll see if that helps.

 

[glowplug]

Wishfull thinking methinks. Although they share the same reservoir any air in the clutch systems will never be purged by bleeding the brakes. They have a separate pipe system.

 

[BikeDoc]

Ah, no.
I was meaning the fresh fluid might help the Clutch (has been graunching into reverse).
Still have to try bleeding it at some stage.

 

[glowplug]

Read the guide I did on bleeding the clutch. Trust me, many many hours of trial and error went into making that masterpiece. A gunsons easibleed, the angle of the car and the retention at full depression of the clutch pedal are all imperative to a successful bleed.

 

[BikeDoc]

Full depression?

Will have a read, thanks.

 

[glowplug]

I forgot to say that before doing anything lubricate the clutch fork shaft first. Get some WD40 and spray plenty under the lever so that the lube finds it's way down the shaft as it runs into the bell housing. spray then get someone to pump the pedal and then spray some more. The rod seizes up over time and gives ALL the symptoms of a bad clutch. If this still doesn't help then persecute the rest of the journey.