25 replies to this topic

[Minigman]

Have you checked the wok for cracks?
I vaguely seem to remember someone having one that had cracked in the area of the plunger or maybe the release arm pivot which caused clutch problems that were difficult to diagnose.

I’ve not noticed any cracks when inspecting it. But that’s maybe my next purchase.

[Minigman]

You say everything is new, but have you used quality components?
I’ve had cheap slave cylinders that hit the end stop before fully getting sufficient travel, a lengthened rod sort of fixed it but it never felt right. A genuine slave cured the issue.

I’ve bought the best I could. Genuine slave cylinder was used from minispares. I tend to avoid the cheapest stuff. I bought two different rods which varied in length by 3mm. My next move will be to buy a replacement wok, master cylinder and then the MED clutch arm kit if that still doesn’t work.

[Ethel]

Why not put the effort in to diagnosing where the problem is?

 

Measure how much movement you're actually getting from the slave piston. Measure the travel of the clutch plunger.

[hunterg30]

You say everything is new, but have you used quality components?
I’ve had cheap slave cylinders that hit the end stop before fully getting sufficient travel, a lengthened rod sort of fixed it but it never felt right. A genuine slave cured the issue.

I’ve bought the best I could. Genuine slave cylinder was used from minispares. I tend to avoid the cheapest stuff. I bought two different rods which varied in length by 3mm. My next move will be to buy a replacement wok, master cylinder and then the MED clutch arm kit if that still doesn’t work.

You mention that a master cylinder will be next , have you put a new one on now , if you have not changed it then this is more than likely the problem . Just had to do mine , tin one bought it off Somerford , don't bother with the bloke selling tin ones on eBay ,several weeks waiting

Edited by hunterg30, 15 July 2020 - 12:05 PM.

[Chris1275gt]

Had my mini 2 1/2 years the biting point was on the floor, had the engine and box rebuilt, its second +20 rebore, every clutch component has been changed the oval pedal clevis pin hole welded, still on the floor. I extended the slave rod 5mm. Biting point halfway along the pedal travel done 3000 miles mostly round town and worked perfectly never a crunch. I read a thread where Moke Spider suggested that maybe the flywheel goes a bit further on the taper of the crank causing this change in the angle of the arm and the need sometimes for a slightly longer push rod so that's good enough for me, and time seems to be proving him right.

[Daz1968]

A few years ago I had the same problem and after replacing everything that can wear I solved it by welding a short piece of bar on the pushrod and ground the weld flush, think I still have that rod in the car and have had no issues since. I have no idea why I had the problem and it was only way it could be solved. I checked everything for wear on latest build and can’t find anything wrong

[CK's mini]

Like Chris1275gt said, I had a similar issue on my MG Midget (works the same as the mini), i replaced everything gearbox end but still have the same issue, it turned out to be the hole in the clutch pedal where the pin goes connecting it to the master cylinder. It had worn slightly (maybe 0.5mm if that), I welded it and re-drilled the hole, fitted a new pin and it was perfect

[mini13]

Its worth pulling the startor motor off so you can get a DTI onto the backplate and see how much its moving, IIRC your looking for 50thou or better of movement.

[Minigman]

Had my mini 2 1/2 years the biting point was on the floor, had the engine and box rebuilt, its second +20 rebore, every clutch component has been changed the oval pedal clevis pin hole welded, still on the floor. I extended the slave rod 5mm. Biting point halfway along the pedal travel done 3000 miles mostly round town and worked perfectly never a crunch. I read a thread where Moke Spider suggested that maybe the flywheel goes a bit further on the taper of the crank causing this change in the angle of the arm and the need sometimes for a slightly longer push rod so that's good enough for me, and time seems to be proving him right.

I swapped the flywheel out for a standard one in order to rule out this issue. Still the same. Not yet changed the MC.

[Minigman]

A few years ago I had the same problem and after replacing everything that can wear I solved it by welding a short piece of bar on the pushrod and ground the weld flush, think I still have that rod in the car and have had no issues since. I have no idea why I had the problem and it was only way it could be solved. I checked everything for wear on latest build and can’t find anything wrong

I’m on the way to creating an adjustable rod now. Parts been ordered.

[Minigman]

Like Chris1275gt said, I had a similar issue on my MG Midget (works the same as the mini), i replaced everything gearbox end but still have the same issue, it turned out to be the hole in the clutch pedal where the pin goes connecting it to the master cylinder. It had worn slightly (maybe 0.5mm if that), I welded it and re-drilled the hole, fitted a new pin and it was perfect

I’m yet to dismantle the pedal clevis pin but will attack that at the weekend.