Intermittent clutch problem

Intermittent clutch problem

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sunbeam alpine

Original Poster:

6,936 posts

187 months

Saturday 22nd November 2014
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Yesterday I got stuck in traffic, and suddenly had no clutch frown

The pedal went to the floor with nearly no resistance, and I couldn't select any gear. The pedal came back up and after a few pumps of the clutch, everything was back to normal.

What is weird is that there is no fluid loss (reservoir is still on max), and the slave cylinder is dry (not leaking). I guess it's the seal on the master cylinder failing, but I would have thought this would still allow fluid to leak, and therefore the level to drop.

It happened also once this summer - in July SWMBO rang me to say she couldn't get a gear. By the time I got there everything was fine so I didn't think anything of it.

In July the fluid was the normal colour, now it's a nasty brown colour.

I don't know whether to just replace the fluid and bleed the system, and wait to see what happens, or bite the bullet and replace the master cylinder. I replaced both master and slave about 5 years ago.

I've taken it for a drive again today and it's fine.

Anyone got any suggestions?

Mroad

829 posts

214 months

Saturday 22nd November 2014
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As a first option and if the fluid hasn't been changed for 5 years then just change the fluid and bleed it through properly.
The clutch fluid should be treated the same as brakes, change the fluid every 2 years. The clutch often gets overlooked.

If that doesn't work (bleeding can be a pain on some clutches some make sure it's done properly) and inspecting the rest of system (slave, master, servo and pipework in between) doesn't show up an issue then it could be the master cylinder.

The master cylinder internal seals can fail or the bore may become scored which stops it pushing adequate fluid to the slave cylinder (it just flows around the damaged seal/bore), this would not show as up as a leak.



Edited by Mroad on Saturday 22 November 14:22

crossy67

1,570 posts

178 months

Saturday 22nd November 2014
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What car is it?

Sounds like master cylinder seals are failing to me.

PositronicRay

26,957 posts

182 months

Saturday 22nd November 2014
quotequote all
If the master cylinder is good could it be the slave? Can you get to it to have a look?

sunbeam alpine

Original Poster:

6,936 posts

187 months

Saturday 22nd November 2014
quotequote all
Thanks for the replies -

I also suspect the master cylinder

The car is a S4 Alfa Spider

Slave cylinder seems fine - dry and not leaking

smile