2nd fault in as many days...

[100K+]

Went out to day to check up on possible wheel bearing noise, come home and 2 hours later go to go out again and the clutch pedal is almost to the floor - about 1" of travel. I have pulled it up with my hand and have driven around for about an hour and there is no difference in my mind to how it was yesterday and before, and how it is now. I'm thinking clutch slave cylinder failure, as I experienced this with my 2004 V70, but did not have a dropping clutch pedal.

I have been under the car and removed the undercover, which is unmarked - literally. The connection between the clutch housing with a pipe and bleed nipple is also bone dry. Looking around the engine is amazingly tight with no leaks evident of any fluid. My 2004 V70 leaked fluid onto the snow - easy find
I enclose a few pics -showing the bleed nipple and the base of the clutch housing which has a crescent moon cut out. Black charge pipe is to edge of image.Would I be correct in thinking any fluid from the clutch slave cylinder would leak from this point.
I checked the fluid reservoir and its still full to the max. I don't see this as a "one off"
As usual thoughts appreciated.
Cheers
Bob
PS As challenges usually occur in 3's no doubt I'll be back tomorrow seeking more guidence and advice.

[capt jack]

Sounds as though you may have a problem with one of the seals inside either the master or slave cylinder.

Instead of the fluid moving as it should with piston it'll move past the piston, leaving the pedal stranded at the bottom end of its travel. When you pulled the pedal up the fluid simply found it's way back to where it's meant to be.

There doesn't have to be any external loss of fluid as the problem is that faulty seal is internal - the fluid is simply ending up within the wrong part of the cylinder at the wrong time.

Chances are it'll be OK for a bit, but the risk is it could leave you stranded without warning.

I'm guessing the slave cylinder on these cars is internal, in which case I think it'll be a transmission off job to replace it. I'm not sure, but I wonder if possibly a fluid leak could contaminate the clutch itself?

There's something to be said for good old cable clutches - return springs and cables were not that hard to replace! I had a clutch return spring snap on a 740 many years ago. I needed a tow, but it took minutes and cost pennies to fix.

Jack

[100K+]

Originally Posted by capt jack

Sounds as though you may have a problem with one of the seals inside either the master or slave cylinder.

Instead of the fluid moving as it should with piston it'll move past the piston, leaving the pedal stranded at the bottom end of its travel. When you pulled the pedal up the fluid simply found it's way back to where it's meant to be.

There doesn't have to be any external loss of fluid as the problem is that faulty seal is internal - the fluid is simply ending up within the wrong part of the cylinder at the wrong time.

Chances are it'll be OK for a bit, but the risk is it could leave you stranded without warning.

I'm guessing the slave cylinder on these cars is internal, in which case I think it'll be a transmission off job to replace it. I'm not sure, but I wonder if possibly a fluid leak could contaminate the clutch itself?

There's something to be said for good old cable clutches - return springs and cables were not that hard to replace! I had a clutch return spring snap on a 740 many years ago. I needed a tow, but it took minutes and cost pennies to fix.

Jack

Yes slave cylinder is internal, and a leak does contaminate the clutch. This is what happened with my 2004 V70. Fortunately I had a Volvo extended warranty which covered the cost. For good measure the DMF was found to be damaged too. It also was replaced. The new only bad bit was I had to authorise the removal of the gearbox at my risk until they found a warranty issue. Ie if they did not find a warranty claim I’d be responsible for labour costs. As there was evidence of failure I told them to proceed. Not sure how I would proceed if this was the case today.
Change master cylinder,( lower cost)then the slave..?
Cheers Bob

Edit:- Thought...Assuming its a seal issue..
The pipe between the clutch master cylinder and where the pipe disappears into the gear box housing is metal+rubber. If I clamped the rubber section, that would reduce the flow and if pressure were felt at the pedal ( cos the master seals were OK, the slave seals would be at fault. No pressure would indicate the fluid was bye-passing the seal = master cylinder fault.
Does this sound logical?
It would only would work with a permanent fault, and at the moment the pedal has remained normal position and operation over night.

Cheers
Bob

[FreshAir]

Originally Posted by 100K+

Thought...Assuming its a seal issue..
The pipe between the clutch master cylinder and where the pipe disappears into the gear box housing is metal+rubber. If I clamped the rubber section, that would reduce the flow and if pressure were felt at the pedal ( cos the master seals were OK, the slave seals would be at fault. No pressure would indicate the fluid was bye-passing the seal = master cylinder fault.
Does this sound logical?

It sounds totally logical and good idea to me.