Clutch issues!

[Stevo302]

Hi guys,
Looks like I got the Wong bits. (Clutch master and slave) Thought these were off a triumph 2500.
Anyway as you can tell the holes are the wrong size to fit the pipe I had. Can't send them back as I've had them for ages.
Can I tap them to the bigger size? (Easy to buy and do?),
Change the pipe to the smaller size? (Will this make any foot peddle difference?),
Get new parts with correct hole? (Simple but more expensive),
1971 Vixen 2500, but with a later 1974 2500 TC engine.
Thanks in advance,
Stevo.

[phillpot]

you could pipe with 3/16" brake pipe, in theory the added resistance will make clutch heavier but quite possibly not noticeably?

I think I recall someone else having similar issue and they drilled the smaller pipe nut out to take 1/4" pipe?


If you go 3/16" can you adapt at slave cylinder?

[Gary C]

cant see it would make any real difference to the pedal, if the piston diameter is the same size that is. When it comes down to it, there should be no significant 'flow' in a hydraulic system (just enough to push the pistons back out, then its all just force).

[phillpot]

Gary C said:

there should be no significant 'flow' in a hydraulic system .

I believe that is why clutch systems tend to be 1/4", there is a lot more flow than a braking system.

Clutch pedal goes to the floor, hopefully your brake pedal doesn't

[yosini]

Hi,

I remember exactly the same dilemma on my Vixen 2500 about a year or so back. Changed the slave first for a new triumph unit, which didn't bring my gears back so I swapped the master cylinder and it was then I realised the old plastic pipe between didn't fit the new master. So I replaced the pipe with a new metal braided one (again from a Triumph place). Nice bit of kit but although the new one fitted it seemed somewhat shorter and more awkward to attach to each end. But after a lot of disgusting fluid all over the floor and plenty of grazed knuckles it all works now.

Still feels reasonably light as a pedal too.

Cheers

Joe

[Stevo302]

yosini said:

Hi,

I remember exactly the same dilemma on my Vixen 2500 about a year or so back. Changed the slave first for a new triumph unit, which didn't bring my gears back so I swapped the master cylinder and it was then I realised the old plastic pipe between didn't fit the new master. So I replaced the pipe with a new metal braided one (again from a Triumph place). Nice bit of kit but although the new one fitted it seemed somewhat shorter and more awkward to attach to each end. But after a lot of disgusting fluid all over the floor and plenty of grazed knuckles it all works now.

Still feels reasonably light as a pedal too.

Cheers

Joe

So did you use the smaller DIA hole/pipe then?
I'm thinking of sending both off to be re tapped to the larger/ original.
Cheers.

[Bull McCabe]

You could try something like this. Would be quick and easy.

https://www.carbuildersolutions.com/uk/brass-union...

[Gary C]

phillpot said:

Gary C said:

there should be no significant 'flow' in a hydraulic system .

I believe that is why clutch systems tend to be 1/4", there is a lot more flow than a braking system.

Clutch pedal goes to the floor, hopefully your brake pedal doesn't

oooops,sorry, just perusing and saw a master cylinder and made a leap

yep your right,

[anonymous-user]

If the pedal goes to the floor without engaging the clutch = go for a larger diameter master cylinder. It resolves it.
If it goes to the floor and hits solid go for smaller.

[Stevo302]

Both the bore ID are the same on the old and new units so it would only be the new pipe I will make up that will be any different. But how much different will it make?
I still want to get them both re tapped if possible, ive asked an engineer and awaiting a response.

Thanks for all the help again in this matter,
Stevo.

[phillpot]

Always good to get a professional opinion, depending what sort of engineer he ( or she) is

[anonymous-user]

Stevo302 said:

Both the bore ID are the same on the old and new units so it would only be the new pipe I will make up that will be any different. But how much different will it make?
I still want to get them both re tapped if possible, ive asked an engineer and awaiting a response.

Thanks for all the help again in this matter,
Stevo.

The pipe diameter makes no difference, it can’t? It’s the master volume moved that’s important, the pipe volume is a constant

[phillpot]

It can! A thinner bore pipe will have a greater resistance so to move a set volume of fluid in the same time will take a greater pressure. Possibly not noticeable but if your clutch is already "heavy" you wouldn't want to do anything to make it worse.

Manufacturers don't use a larger bore (more expensive) pipe just for the fun of it ...

Edited by phillpot on Monday 5th February 15:25

[ATE399J]

phillpot said:

It can! A thinner bore pipe will have a greater resistance so to move a set volume of fluid in the same time will take a greater pressure. Possibly not noticeable but if your clutch is already "heavy" you wouldn't want to do anything to make it worse.

Manufacturers don't use a larger bore (more expensive) pipe just for the fun of it ...

Edited by phillpot on Monday 5th February 15:25

Absolutely right! You are trying to push the same volume of fluid down a narrower pipe.

[anonymous-user]

That’s viscosity for you! If we’re talking travel it’s a constant I changed large to small to get the travel within the range.