Clutch Master Cylinder

[geryS2]

clutch

mine broke today !!

does that 4 AO 721 401 replacement part got used by others ?

any weakness in other parts in the clutch system to look for while doing the job ?

cheers

[jade]

mine broke today !!

does that 4 AO 721 401 replacement part got used by others ?

any weakness in other parts in the clutch system to look for while doing the job ?

cheers

Works for me

[Rusty]

Good news, I've got a prototype linkage brace being made up This will enable MCs with a worn or damaged (due to manufactiuring defect IMO) rubber joint to be left on the car, it can also be used to prevent failure occuring in the first place! It's not a miracle worker but should save all but the worst affected linkages.

[Rusty]

Prototype is now made and I'll be fitting and testing it ASAP (yes, my clutch linkage is shot after 30k miles )

[s2_bo]

30K, thats good going Andy considering you don't exactly treat it respectfully!

[Rusty]

if it was a mechaincal part then I'd agree but it's a simple linkage that should really last the life of the master cylinder. IMO, it's a manufacturing error, as the 10V item that I've been leant is of the same design and is in excellent working order and I'd wager that it's many years older...

Anyway, I've got to test fit the part to the car and then tweak the design a little to make a production item. Cost should be about £30, or around 1/4 the cost of a new ABY cylinder and many times less than the cost of a new cylinder fitted! This can be used on all master cylinders for B3 and B4 cars.

The 'saver' can be fitted to linkages in most conditions to save the linkage from breaking, repair it to a useable condition or remove the flex from older linkages. Watever the use, it'll be a load easier than replacing the whole part

[Bowlerwell]

This sounds very useful. I'll keep a keen eye on how your testing goes...

[Rusty]

Yeah, I'm hoping this will be rather useful to most people... a lot more useful than ripping out a perfectly healthy master cylinder because the linkage has gone

[Fat Audi 80]

I always thought this would be a good little project but didn't have time to tackle it with a day job and the family.

Can't wait to see the results Andy, I will deffo have one myself to go in the car or on the spare parts shelf.

Nice one!

Cheers,

Steve

[Rusty]

It's a simple bit of kit and effective

[macspring]

I'm in the queue for a new one, so keen on an update when you're ready.

Thanks.

[Rusty]

Here's a couple of pictures of the prototype. Simple, but effective...

[Fat Audi 80]

Andy,

Does the joint need a certain degree of freedom in it's original guise and does this bracket still provide that? I have never been up close and personal with the linkage, so just asking the question out of curiosity.

It does look very substantial though.

Cheers,

Steve

[Rusty]

No, I've never really understood why the joint is done the way it is, it might take out a little vibration or something like that but there's no requirement for movement, that I've found.

I've fitted the prototype and will be testing it - see pics.

It was fiddly to fit but that was more due to access and angling of my body and limbs than anything else.

I'll make a few adjustments to the design and get a cost for a batch

[Fat Audi 80]

Which is why I cannot understand why the OEM mechanism has been made so flimsy in the first place?

Looking at your design, presumably you have designed it so that you can fit it without stripping down the MC and pedal?

Looks very good from here and would make a good preventative maintenance fit.

Cheers,

Steve