2nd fault in as many days...
 

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.

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

It sounds totally logical and good idea to me.

time for action
 

Well it has happened again. Daughter this time driving, went to change gear and pedal went straight to floor. She lifted pedal and got car home with out further drama. Have read much about CSC being an issue on M66 gearbox, but that will be a very expensive repair ( I'm too old to be doing this major work) However, it could be the master cylinder which would be a cheaper repair.
Sat in car tonight repeatedly pushing clutch pedal, after about 10 minutes pedal went straight to floor and was lifted back up. Pushing down again, the pedal was about 30/50% harder to push and again the same when I tried a couple of more times. I checked around the clutch pedal and bone dry, the fluid res. was also still full. I returned to the pedal and the excess stiffness had gone and the pedal had returned to "normal"
How do you tell which end to repair.? Cheap end first and hope you guessed right? Will a garage be any more able to advise? Do you think a Volvo garage would be better/more knowledgeable. The older you get the easier it is to become confuzzeled

Cheers Bob

At the risk of increasing the confuzzle factor, I think I'd be looking for an opinion from a friendly dealer/independent. Good luck.

Biting the bullet
 

It’s done it again…so biting the bullet. Am arranging to take the car to a main dealer,and replace both slave and master cylinders. As I intend keeping the car long term, the 80k mileage, limited caravan towing, I have decided to invest in new pressure and drive plates and a dual mass FW. Seems short sighted not to while it’s all apart.
Got what I think is a good deal using genuine Volvo bits.
Cheers Bob

Hi
I would have thought if it was the slave cylinder with the problem, ie fluid passing the seals, the fluid would be leaking out and the level dropping. (if that has happened there would probably be fluid dripping out underneath). With the Master, if the fluid is leaking past the seals it will just end up back in the reservoir and therefore not leak externally.

There are several points here.
There is no fluid leaking from the bell housing joint, in fact the engine is still oil seal wise very tight. So if it is a slave issue oil is passing internally,as you suggest with the master cylinder, which is also bone dry. My issue has been it’s an intermittent fault, so replication has been almost impossible. Without the fault present diagnosis too is impossible. It’s not helped by there being no Vida diagnostics available to record fault codes. It would have been very helpful. Cars going in tomorrow and should be back at w/end. Will advise what is discovered.
Cheers Bob

Final Update...
 

Got the car back today from dealers. Budget was £2k and I was able to get under this with a little bit to spare. Using all Volvo purchased bits and labour. The Volvo tech was unable to say which cylinder ( master or slave) was causing the dropping pedal, both appeared to be fine. I have attached pics of the returned items (except the master cylinder, as it looks like new)
Observations:
The pressure plate shows no sign of abuse, ( to me) the inner plate is totally smooth. the fingers where the slave cylinder locates do show signs of some wear, whether significant or not pass. The slave cylinder has a small degree of play ( the bit I'm holding) some 2/3mm. If it were a wheel bearing I'd be having some concerns. The same degree of play is in the DMF (about which I know nothing) the inner plate has a 2/3mm of lift from the back outer plate, and it has about a 5/7mm rotational play about the circumference. Whether this play is working tollerence or wear, I don't know. Just reporting.
Where I go from here I don't know, my fingers and toes are crossed, but surely I have resolved the issue, time will tell.
Car : V70 2015MY D5 Manual 80K miles.
On to next job....
Cheers Bob