Diesel Clutch Hydraulics - Are They Still Problematic ?

[Sonic ZS]

As most members on here will know, the diesel (and possibly some petrol) versions of the 75/ZT seemed to gain a reputation for early failure of the plastic clutch slave cylinder following a replacement.

Now, not wishing to tempt fate with my own car - and it may just be my imagination, but there seems to be distinct lack of posts regarding this issue over the last few years ?

It could, of course, be that numbers are dropping as cars are being scrapped, or that as the models are getting older they are being used less so covering lower mileages ?

But can we now assume that the slave cylinder manufacturers have finally sorted the problems and the clutches are becoming suitably reliable again ??

I replaced my original Rover clutch about 3 years ago at 155k (surprisingly due to centre plate spline fracture, not hydraulic failure) and the new LuK Repset 3-piece kit has now covered about 20k, and touch wood, it's working perfectly.

So would be interested to hear other member's thoughts and experiences.....

[Lee T]

The problem with the slave is the two plastic tangs that hold the body parts together cut a groove around the lower body part allowing the top half to rotate, spinning the spring with it and that creates heat. My own slave ejected the top half with bearing, then the spring followed leaving the base held by the hydraulic pipes, as soon as I slid the gearbox back.
There is a How To on here somewhere, showing how to modify the slave to prevent this. It involved cutting two grooves in the upper body and placing a self rapper in the lower body through the groove allowing free travel of the slave but preventing the tangs doing their thing.

Lee.

[trikey]

What most folk forget to do is replace the guide tube, I've never had one fail early when the guide has been replaced.

Sent from my SM-S711B using Tapatalk

[MSS]

Originally Posted by trikey

What most folk forget to do is replace the guide tube, I've never had one fail early when the guide has been replaced.

Sent from my SM-S711B using Tapatalk

That , even to me an amateur, is pretty obvious. Which is why when my car came over to you for the clutch change Andy, it had a new guide tube and the sealing ring.

Since you replaced it the clutch has been light and operates perfectly!

[Sonic ZS]

Originally Posted by trikey

What most folk forget to do is replace the guide tube, I've never had one fail early when the guide has been replaced.

Sent from my SM-S711B using Tapatalk

Out of interest, what's the issue with the guide tube (and not changing it) ?

I checked mine carefully when changing the clutch and it luckily had nothing more than very slight polishing to the surface, so deemed it was good to reuse

[Sonic ZS]

Any other thoughts on this ?

[biffa75]

The guide tube aids the slave cylinder movement and over time can end up with wear and grooves from dust and other debris eventually the slave can't move as freely on the guide tube and as I believe results in the slave extending beyond it's usual extending length and ruins the seals.

Whenever we have done clutches on any car not just 75s, we do every thing in its entirety,
full three piece clutch kit
(dmf if fitted)
crankshaft rear main seal
Guide tube and any seals associated to the guide tube
Driveshaft oil seals
Gearbox oil
Master cylinder and pipework

We also like to try and keep all the parts we buy, from the same company as the parts are designed and engineered to work together at designed pressures and so on..

When we bought our tourer the clutch was slipping under load in 5th gear. We replaced everything as listed above with the only exception being the master cylinder (went against my own rule) and fitted an ap Lockheed clutch master cylinder instead of Luk as per my own rules and had no end of issues with failing master cylinders. This was due to others negative comments regarding Luk master cylinders... I've now had an Luk master cylinder fitted for 8 months and not had an issue and in 2.5 years I've now covered 30k miles between myself and my wife used for work, shopping etc etc and 85% of that driving has been round town through villages etc so the clutch hydraulics.have taken quite a lot of use.

I'd also strongly advise using the correct torque figures when fitted the clutch cover plate and flywheel bolts etc as I know some people ignore these figures.

You can now also get full 3 piece Luk clutch kits along with the dmf on eBay from parts in motion when the 15% discount codes are running for just under £400 with free 3 day delivery!

I know many people advise that the dmf can be re-used and specify the tolerance limits in regards to engagement but personally, I generally ignore this and just fit one. A cost yeah but saves me the frustration of dropping the gearbox again in saying 6 months and anything to aid reliability.. other cars of the same era i.e MK3 Mondeo tdci, tddi, E46 320d (same engine) all recommend changing the dmf when replacing the clutch, seems odd to think these would be any different.

Do them by the book, fit parts that are designed to work together from the same company and worry not..

Regards rob