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Manual clutch issue

Posted: Wed 10 Jan, 2018 9:10 pm
by GREENPEDRO
Hi All,

Pedro, the green 300TD manual wagon, has an issue.
Went to move out of the garage the other day and on putting my foot on the clutch, it went straight to the floor, No clutch !!!
Left it a few days and noticed a lot of hydraulic fluid on the garage floor.
Mopped the spill up and noticed that brake fluid reservoir was almost empty, topped it up again and noticed that fluid was leaking out between the manual gearbox and the clutch housing at about two drips per minute.

What does this mean, apart form the obvious of no clutch, is it a major issue or something more easily fixed.

All suggestions appreciated as I am a novice.

Cheers
Larry

Re: Manual clutch issue

Posted: Wed 10 Jan, 2018 10:38 pm
by Thunderbolt
Sounds like the slave cylinder, normaly pretty easy job dont know about these cars though
Cheers

Re: Manual clutch issue

Posted: Wed 10 Jan, 2018 10:48 pm
by CraigB
I don't know where the clutch slave cylinder is compared to where it is dripping, but it must be coming from there or a flexible line going to it. I don't know how readily available a replacement slave is or how much but that is the easiest solution. If it is in good shape you could get away with new rubbers or Power Brakes in Adelaide (and probably others) do a stainless sleeves on anything.

Re: Manual clutch issue

Posted: Thu 11 Jan, 2018 12:38 am
by mathuisella
I have a manual as well, although i did the manual transmission swap myself in the back yard...

I would dare say your clutch slave is leaking internally and the liquid is coming out of the emergency fluid drain port between the slave cylinder and the gearbox.

Either that or my 2nd guess would be at the line that goes between the clutch slave and the liquid resovour, would need some good pictures to confirm where it's coming from.

clutch slave cylinders can be wholly bought online and through mercedes and i gather our sponsor here as well.

but the 3rd party ones won't be exactly the same, they may not have the same travel distance ect: so be careful

Re: Manual clutch issue

Posted: Thu 11 Jan, 2018 8:34 pm
by GREENPEDRO
Thanks guys for your interesting thoughts.
It makes sense to my limited knowledge that it may be the clutch slave cylinder gone ca-put.
It sits on top of the manual gear box and I can't see any fluid escaping from there so can only assume (dangerous) that the slave cylinder is leaking into the bell housing and dripping out via the emergency fluid drain port as suggested by Mathuisella (where did you dream up that name from).

Will do some more investigation before taking any action, so at present, Pedro is on stands in the garage.

Cheers
Larry

Re: Manual clutch issue

Posted: Thu 11 Jan, 2018 10:29 pm
by mathuisella
hehe, the name kinda suits it as if the drain port wasn't there, all the fluid would drain into the bellhousing and you'd end up with liquid all over the clutch plate(s) and that's just an accident waiting to happen....

a few good clear shots to trace the liquid where it's leaking from :) either the clutch itself, or the connection to the fluid res in the engine bay are my thoughts.

Re: Manual clutch issue

Posted: Fri 12 Jan, 2018 9:06 pm
by GREENPEDRO
Thanks Mathuisella,

I have very limited knowledge of this stuff, but can I presume that it is the slave cylinder on top of the gear box that is leaking into the bell housing and if so, doesn't that mean that fluid would have been leaking over the clutch and clutch plate assembly which, as you say, is not good.

Should I change the cylinder as a first option and see what pans out ?

By the way, there are no obvious signs of fluid leakage anywhere else apart from the slow drip from the join between the gear box and bell housing.

Cheers
Larry

Re: Manual clutch issue

Posted: Mon 15 Jan, 2018 10:58 am
by Bartman4800
It is quite common.

Brake fluid is hygroscopic (attracts moisture) and should be replaced every 2 years.

The water drifts to the lowest point (in this case your slave cylinder) and starts to rust the cast iron body...
When you take it off, check the hose for cracks and replace if in doubt.


Bart

Re: Manual clutch issue

Posted: Mon 15 Jan, 2018 8:31 pm
by GREENPEDRO
Thanks Bart, good info and interesting about the moisture attracting properties of brake fluid.

I am in the process of trying to remove the slave cylinder and having a little trouble due to the very confined space to allow for hand and tool room etc.

Thanks again.
Larry

Re: Manual clutch issue

Posted: Mon 15 Jan, 2018 9:39 pm
by CraigB
I didn't realise the water went to the lowest point. That explains just how effective it is when people go to track days without changing fluid - disc and caliper get hot, boils all the water down there to gas and pedal goes straight to the floor. Happened to a friend in a 6.9 despite a warning - he looked very pale faced when he came in after running off the track! He was convinced something else had broken. I told him to leave it for a bit to cool and then try the pedal again and sure enough it firmed up again once the gas turned back into water. But when you need your brakes the most, when they get hot and that's when they will go.

Re: Manual clutch issue

Posted: Tue 16 Jan, 2018 4:18 am
by mathuisella
ah yes, i remember now, oh the pain of such tight spare. My suggestion is to do what i did.

first spray some penetrative oil around it and let it soak for a bit.

then using every socket extension you have use this method... also may use the universal joiner/ knuckle joint, go at it from down the transmission tunnel further back. It makes life so much easier when trying to get to the starter motor, upper bellhousing bolts as well as the top clutch slave cylinder.

if you're in brisbane i'll be happy to pop over and help.
ow445.jpeg

Re: Manual clutch issue

Posted: Tue 16 Jan, 2018 12:07 pm
by Bartman4800
I know it is a bit of a hassle, but wouldn't it be easier to remove the propshaft and take the gearbox out?

That way you can have a good look at the clutch fork and the throwout bearing too...


Bart

Re: Manual clutch issue

Posted: Tue 16 Jan, 2018 12:09 pm
by Bartman4800
CraigB wrote:
Mon 15 Jan, 2018 9:39 pm
I didn't realise the water went to the lowest point. That explains just how effective it is when people go to track days without changing fluid - disc and caliper get hot, boils all the water down there to gas and pedal goes straight to the floor. Happened to a friend in a 6.9 despite a warning - he looked very pale faced when he came in after running off the track! He was convinced something else had broken. I told him to leave it for a bit to cool and then try the pedal again and sure enough it firmed up again once the gas turned back into water. But when you need your brakes the most, when they get hot and that's when they will go.
The brake fluid is lighter than water. Next time you replace the brake fluid chuck in a few drops of water in the jar with dirty fluid and see it pool on the bottom.
They lie on the floor of the jar in nice bubble shapes. Same applies for Diesel and any other fluid lighter than water...

Re: Manual clutch issue

Posted: Tue 16 Jan, 2018 6:29 pm
by GREENPEDRO
Thanks for the suggestions guys, I will certainly try them all and thanks Mathuisella for your offer of help.
Unfortunately, I am on the Central Coast of NSW, no where near Brisbane, but you are very welcome to come down the coast, a few beers await.

Cheers
Larry