Dragging clutch - S3 Spider

I have recently put my engine and gearbox back into my 1989 S3 Spider after a head rebuild and new clutch. I bled the clutch some weeks ago and have had the engine running to shunt the car in and out of my garage to enable other odd jobs to be done prior to the MOT. A couple of weeks ago I noticed that the clutch was dragging, such that it was difficult to put the car in gear with the engine running. If I pumped the clutch a few times, it seemed to help, so I thought I may have some air trapped somewhere. Since I was to bleed it again, I replaced the old (slightly cracked) flexible pipe. The result was a much lighter clutch - too light in fact and it was worse than ever, despite several attempts to bleed it. Looking underneath whilst my son helped by pressing the pedal, I noticed that the slave cylinder was only pushing the clutch mechanism about 10mm or less, and I was expecting it to be more in the region of 10-15mm. Nothing seemed to improve this despite numerous attempts at bleeding. In the end, I have adjusted the rod between the pedal and the master cylinder and it now seems to be ok - I think!

The problem seems to have been due to the pedal not having enough throw to operate the slave cylinder far enough. Adjusting the rod at the master cylinder so far seems to have sorted the problem, but why did I have to do this? It worked prior to the clutch being changed. Incidentally, the slave cylinder was changed about 500 miles ago due to a leak on the old one, so I can rule out any problem there.

I'm pleased to have hopefully fixed the problem, but mystified as to why the problem came about. Any ideas?

This suggests that the master cylinder bore is internally corroded for just the first bit of movement, with fluid passing the seal instead of pushing the slave. Corrosion usually from water mixing with the fluid over the years. This sounds more feasible than my usual attempts at distant diagnosis.

Thanks for your suggestion. Although the car is approaching 20 years old, it spent the first 12 or so in California, and is remarkably rust and corrosion free (you should see inside the brake drums!). I'm beginning to think that I have a broken or breaking lever arm shaft, which I will investigate tomorrow. I found this on an old thread on the alfabb.com site and unfortunately for me it is looking just like my problem..... These links are copied over, just in case anyone else is having similar problems:

Replacing the Alfa Clutch Pedal Shaft

http://home.hiwaay.net/~ortak/Clutch...pivot_arms.htm

If anyone has other suggestions, please post them here.

You may have had a master or slave cylinder problem for some time. As the clutch plate wears it reduces in thickness. The new clutch will be thicker (and the new pressure plate harder to push) it will alter the position where the slave cylinder operates. If the master cylinder inside or seal are warn or damaged, it will not push so much fluid. If you put the clutch down and hold it down (while in gear) if the clutch slowly starts to engage then the master cylinder needs attention.
(silly question, you have bled the slave with bleed uppermost) Not worked on LHD cars, so if you can adjust master cylinder, try it (after the hold down test)

Thanks for your comments, Filbyman. The slave was bled with the bleed nipple at the top. I've since found out that it appears to be a problem with the clutch lever shaft, and either the weld is giving way on the lever on the end of the shaft or the shaft is sheared inside, but still managing to offer a limited amount of friction to try and do something. I'm off to try and take it apart........

One thing that has become apparent is that adjusting the rod length is only covering up the main problem. The rod length should be fixed at 134mm on the lhd model.

The problem is that the weld has cracked on the clutch lever pivot shaft. Although still tight, the lever doesn't provide the full movement on the master cylinder, thus the slave doesn't move enough either, and the clutch doesn't clear properly.
I have taken the pedal box off the bulkhead and removed the shaft, and with the shaft held firmly in a vice, I can just about rotate the lever without the shaft moving! Luckily, I have been able to mark the relevant positions and it is being welded tomorrow. I can the reassemble. I've even managed to do it without having to disconnect the pipes - tight, but just about possible.

Thank you for this information. I have just got my S3 back on the road after a gearbox rebuild and clutch replacement only to experience much the same as you.

I will check the lever pivot shaft this afternoon if the rain holds off, and together with the links you have provided, i hope to be able to remove the shaft myself....

Do you know what the rod length should be for right-hand drive cars?

Originally Posted by mowog

Thank you for this information. I have just got my S3 back on the road after a gearbox rebuild and clutch replacement only to experience much the same as you.

I will check the lever pivot shaft this afternoon if the rain holds off, and together with the links you have provided, i hope to be able to remove the shaft myself....

Do you know what the rod length should be for right-hand drive cars?

Since your car is a Series 3, I assume that it has been converted to RHD. I'm afraid I have no information on this, but from memory, some of the conversions leave the brake and clutch master cylinders in the original place, and have some form of spacer to allow extended brake and clutch rods to run across the bulkhead. If this is the case, I see no reason why it shouldn't be the same. However, there may be more experienced people out there who may be able to provide more information.

The length of 134mm specified for my car is based upon the length of the operating lever, so it could be different if a different lever length has been used on your converted car since a longer lever will give a longer stroke at the master cylinder. My master cylinder, from what I can read from the side, shows: Benditalia T4033*** (where * means not sure!).

The information that I have for older RHD cars (ie official RHD Alfa), states a slave cylinder movement of 11-12mm. The pushrod on the master cylinder should be adjusted to give this, and when correct, the travel on the master cylinder pushrod should be 27mm + or - 1.5mm. This information is taken from my Brooklands book on the spider, and refers to models introduced from 1970 with hanging pedals. This set up is different to that of the S3 though