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Old 28-07-22, 12:27 PM   #1
BackintheFold
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Default Length of Clutch Slave Cylinder Rod ur MB

I won't be touching this for a while, but could someone with an accessible correct length rod please measure it?

As may be obvious, I am not sure if I have a faulty set up. The first thing I want to do is check the length of the slave rod, and also check if my slave cylinder is under pressure from the master cylinder.

I can check the pressure simply enough by opening the bleed nipple, but need to know the correct length of the slave rod to check that. It is possible that the slave rod is hard up against the "stop" in the slave, but is touching the clutch bearing release lever more than it should.


It is now my understanding that this is the only real freeplay that exists in the setup; with the slave rod touching the lever, there should be some freeplay before the lever starts pushing the release bearing. If the rod is too long, it is pushing the release bearing against the clutch all the time.

There should be no freeplay at the master cylinder end-the rod should be able to sit in the cylinder cup at its "stop" position. The master rod should be activated immediately by pressing the clutch pedal, which pushes fluid through the system and starts moving the slave rod. The slave rod should be sat at its stop. When the slave rod starts moving, there is some freeplay until the lever touches the release bearing, and the bearing then pushes the clutch fingers and activates the clutch.
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Old 28-07-22, 01:39 PM   #2
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I don't have a spare slave to check for you but my recommendation would be to buy a new slave and swap it over regardless. It's a fiddly job swapping and a pain to bleed and if you are removing it to check you might as well pop a new one in at the same time. Get a Sachs one as they were original fit.
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Old 28-07-22, 01:51 PM   #3
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And anyone know when the slave changed over to the bolt securing? MB or RR?
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Old 28-07-22, 09:48 PM   #4
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Quote:
Originally Posted by tractor Dave View Post
I don't have a spare slave to check for you but my recommendation would be to buy a new slave and swap it over regardless. It's a fiddly job swapping and a pain to bleed and if you are removing it to check you might as well pop a new one in at the same time. Get a Sachs one as they were original fit.
It’s had a new one only recently. Looks lovely and shiny, with a braided hose too.
My other option is of course to remove it and poke a long screwdriver down the hole to work out the length so that the rod can rest at the stop position at one end and just touching the bearing release lever at the other.

But I’d be happier knowing the rod was the OEM length!

As for when the bolt first appeared my black MB had a bolt, but that could have been put there by Phil Payne instead of the (roll pin?)
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Old 29-07-22, 12:39 PM   #5
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Can I ask what the actual issue is please?

As it doesn't really matter what length the push rod is as long it's within 10mm of correct, the clutch is system is hydraulic and self adjusting so as long as the rod is pretty much the right length it doesn't make any odd's.

In fact I'm pretty sure you'd get away with one 20mm out and still be okay, though I wouldn't like to bet on it.

If you're clutch isn't disengaging or staying engaged, you've either got air in the system or the pressure plate is knackered.

Or possibly you have a totally wrong length push rod, certainly worth checking though.
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