Help! Clutch issues

[badger]

I am having a few problems with my clutch, and am hoping someone may be able to solve it.
When the engine is cold the clutch operates fine. However once fully warmed up after about half an hour or so, the biting point is very difficult to locate, and the pedal almost feels sticky.It makes pulling away from junctions quite awkward and involves pumping the pedal a few times so that I can get the biting point.Also the gear change has a more notchy feel to it.I will bleed the system tomorrow as it hasn't been done for at least 4 years prior to my ownership (6 months)
All opinions welcome

[Jonathan Lewis]

Could be something on the operating mechanism in the bellhousing but, given your comments about pumping the pedal to get the biting point, my first port of call would also be the hydraulics.

You may have a failing seal in one of the cylinders, or the flexible hose may be leaking slightly and allowing air to be drawn in.

[tony]

Just had a similar problem with my S, clutch dragging quite a fit. When I pulled the dust cap on the slave cylinder back it was damp.Fitted new cylinder and problem has gone away.

[Steve Knight]

This can often be the last nylon bit of flexible pipe to the slave. When hot it will slightly swell giving problems. Replace with a short aeroquip hose ( but no one makes one do they ) and the whole length costs a bit. Why are the clutch hydraulics in 1/4" pipe when most other vehicles happily use 3/16" ?

[badger]

Thank you all for your advice. I shall be ordering a new slave cylinder on Tuesday, and will get some new hose from the master to slave as the whole length is the nylon stuff.

[Mike Stevens]

Why are the clutch hydraulics in 1/4" pipe when most other vehicles happily use 3/16" ?

Because you get an odd pedal feel otherwise!

I've replaced the hose from master to slave with 3/16" copper brake pipe, (with a suitable coil at the bottom). Unlike a brake, a clutch requires a lot of fluid movement and with the smaller pipe, the pedal feel is 'heavier' going down that up. I think this is due to the fluid flow restriction of the smaller pipe as opposed to the 1/4" pipe.

When a get "a round tuit" I intend to make up a similar pipe in 1/4" copper....

Cheers,
Mike.

[badger]

Hi all. I'm still having problems, even though I have renewed the slave cylinder and fitted a new braided hose. When the car is cold the clutch works fine and finding the biting point is no problem.However, once the car has warmed up, the peddle feels "sticky" and finding the bp is not easy. When waiting at junctions, holding the clutch at bp is near impossible, so neutral and handbrake are engaged, until I can move off, then it is a matter of trying to pull away without the clutch problem kangarooing up the road too much as the peddle seems to stick just before bp is engaged. Any help or pointers appreciated. Apart from the clutch problem, the old girl runs lovely

[tony]

Looks like it's time to have a look at the master clyinder. You've done the rest of the hydraulics. If fluid is leaking past the piston cup/seal in the cyl. it won't do much for your pedal pressure.

[Alec]

Hello Badger,

I think I would check the mechanical action of the clutch itself, get the car nice and hot so the clutch is misbehaving, disconnect the slave push rod and using mole grips or a bit of pipe on the clutch actuating arm (for leverage) get a feel for it's action, the thrust bearing carrier may be sticking on the gearbox input shaft extension? This should prove whether it is mechanical or hydraulic.
Normally what happens with the plastic pipe is that when it balloons it just doesn't release the clutch properly i.e. it won't go into gear cleanly, but doesn't give the 'kangaroo' symptoms?

Alec