Four months ago we put a new clutch kit including the concentric slave (Valeo kit, alsoinc. flywheel) in a 2004 Merc Sprinter. Two weeks ago it came back with a crap clutch pedal. The brake and clutch fluid (shared reservoir) didn??
sr2,
Mar 20, 8:06pm
Despite having fitted a replaced it still sounds very much like a mastercyl issue. Bit of a long shot but is there enough slack in the clutch pedal linkage when at rest! If someone had previously fiddled with it, both old and new mastercyl??
llortmt,
Mar 21, 12:28am
No adjustment in pedal, the way the master attaches it cant be wrong. There's no way it's been fiddled with since we did the clutch and even if it had been I cant see whats would have been done. Just re-bled it and its fine at first, press the clutch 200-300 times and pedals at the floor again. ps we changed the clutch because it was worn not this problem.
bellky,
Mar 21, 1:12am
You say there's no leaks and the level is still good - could it be sucking air somehow! Or fluid pushing past the cups somehow.
bellky,
Mar 21, 1:32am
"this has happened to my mates van,reverse bleed it from the slave cylinder using a squirty oil can (full of brake fluid of course), cut the flexible hose and push over bleed nipple take top off master cylinder and pump away. an ex mercedes mechanic did this on my mates van and it cured the problem." http://sprinter-source.com/forum/showthread.php!t=2040
llortmt,
Mar 21, 1:54am
Yes it's sucking air, (but where!) bleed it and its all good for a couple of hundred clutch movements.
llortmt,
Mar 21, 1:58am
We've also tried vacuum bleeding, and pressure bleeding but I don't think bleeding is the problem.
sr2,
Mar 21, 3:02am
I don't think bleeding technique is the issue either but if it is providing a temporary fixair has to be getting into the system somehow and I keep coming back to either a restricted compensating port or an obstruction in the fluid supply from the shared reservoir. Just a thought, are you sure there wasn't a gasket / spacer left outwhen the new master cylinder was fitted! You wouldn't be the first (or last) to get caught out by that one.
jmma,
Mar 21, 3:12am
Is there a flexi hose, only other cause I guess, may have been stretched or something.(o:
llortmt,
Mar 21, 3:17am
No spacer and the problem is exactly the same as before fitting the new master.
llortmt,
Mar 21, 3:19am
Yes connects directly to concentric slave, it looks ok, and as it bleeds ok I'd kind of eliminated it.
unbeatabull,
Mar 21, 4:28am
x1
Could be a faulty Slave, even though it was replaced.
intrade,
Mar 21, 4:43am
yea unfortunately thats what i start to think. I would fit a pressure read sensor on to the gearbox inlet if possible to see when it does it if the pressure to the slave still works might have to engeneer some tool best would bea wireless unit reporting back to the laptopvia bluetooth to confirm this.
llortmt,
Mar 21, 6:01am
Yes that my guess right now, I've ordered another, its back on the hoist: box back out in the morning!
sr2,
Mar 21, 7:50am
Make sure you let us all know when you successfully diagnose the problem.
llortmt,
Mar 21, 8:01am
IF, I'm using the scatter gun approach now 'replace everything!
sr2,
Mar 21, 8:04am
I've been there before, you get to the point where you're wondering how the hell am I going to charge the customer for this one!
jmma,
Mar 21, 8:23am
Sounds like you eliminated everything else by replacement, maybe replace this next!
llortmt,
Mar 21, 9:19am
x1
Yes we covered the unions of the hose with grease to attempt to eliminate them, the hose itself is in good condition. But it the slave doesn't fix it, it'll get a new one. Right now I think the slave must be sucking up air at the top somewhere hence no visible leak.
llortmt,
Mar 21, 9:23am
The customer is desperate for the van back (delivery's) and time off the road is well 'time' which is money! so I'm not too worried about that.
cowlover,
Mar 21, 11:15am
Silly as it might sound I think you have not got all the air out.There is a valeo service note that refers to using a syringe to suck air out of their csc cylinders.May not apply to yours as I think it only applies to the type where the bleed nipple on the csc pipe is not at the higest point of the csc.Have you got a pic of the bleed point!
Can't resist but is it about now you need to say "where is Jazz when i need him"!
snoopy221,
Mar 21, 11:26am
Gunna juus have ta punt on uneven fingers on pressure plate and slave sucking air.
Can't resist but is it about now you need to say "where is Jazz when i need him"!
LOL
llortmt,
Mar 21, 6:03pm
x1
It is a Valeo slave but the bleed screw is at the bottom (lowest point) plus vacuum bleeding would be the same as a syringe. I really think the air is out, as remember it lasted over three months the first time.
llortmt,
Mar 21, 6:09pm
It's coming back out today, so we'll soon find out (I hope!). But as I said I think it's the slave sucking air.
llortmt,
Mar 22, 4:59am
Right took box back out, looks like the slave HAS leaked VERY slightly. There was fluid behind the bellows and very slight dampness below it that could only have got there through leaking. Fitted a new one, put box back in, bled it up and 600+ pedal movements later it still has a good pedal. So what should the customer pay for!
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