Lost the clutch

Looks like the hydraulics in my clutch just went, luckily in my driveway.
Clutch pedal goes to the floor with no exertion needed, I had a look at the
hydraulic pusher on the side of the gearbox (740 GLT with M46 gearbox) It
seems to look like it is too far out and brake fluid is leaking out of the
unit around the rubber gaiter. I would guess the pushrod looking piece is
over extended due to wear on the clutch lever side, but it was getting dark,
and I've had a hell of a day, so I just closed the lid and came inside for a
few beers..... Anyone had experience of this? I do have a parts car parked
up in the drive and it has an M47 gearbox. Would the hydraulic side of
things be swappable? I really do not want to drive my BMW 316 I bought for
£50 for too long. It's much harsher on the bumps LOL.

 

From a point at sea, to the circles of your mind, this is Stuart Gray:

If the pushrod is too far out, but still located in the release arm,
it probably indicates failure of the clutch mechanism. This will mean
removing the gearbox and fitting a new clutch kit.

Hopefully, you have only blown the slave cylinder seals. If this has
happened, you will have been pumping a little fluid out every time you
pressed the clutch, and now the reservoir is empty and you are just
pressing on air.

You can get a seals kit, but it really isn't worth it - if the
cylinder is worn or corroded inside you will have wasted your time. Go
to a motor factor (not a Volvo dealer) and get a whole new slave
cylinder for a few quid more. Last time I bought one it was about £12,
but it's many years since I had a manual box, so they've probably gone
up a bit.

Replacement is easy - loosen the flexible hydraulic line, remove the
cylinder (bolts or circlip, depending on type), disconnect from
hydraulic line, fit new cylinder in reverse order, making sure the
pushrod is located properly, tighten hydraulic line, fill reservoir
with DoT 3 or 4 (NOT DoT 5) and bleed through. Job done.

Your parts car will probably not be a good source of hydraulic parts.
Glycol based brake and clutch fluid is hygroscopic and if it's more
than a couple of years old it will have absorbed moisture from the air
(it makes the fluid go dark brown in colour) and corrosion will be a
problem. This could be what has already happend to yours. Change brake
and clutch fluid every couple of years to prevent this.


--

Stewart Hargrave

Faster than public transport


For email, replace 'SpamOnlyToHere' with my name

 

Thankfully it is external to the clutch- Haven't had a proper look yet, been
raining all day here and I'm not in the mood LOL. Mebbe tomorrow.

Stuart.

 

Fixed it today. There was a chunk missing from the seal on the piston inside
the slave cylinder. Then the hose had a pinprick leak. Got it all done now
though. All I need to do is igure out why the crackcase pressure is high.
I've cleaned the flametrap, replaced a hose that was blocked - the little
one to the inlet manifold, but it's still high.

Stuart.
..