OK, so a while back I changed the clutch plate in my warm 1152 and since putting it all back together, the clutch pedal has been much harder than it was previously. The only changes were the friction plate and thrust/release bearing, but now the pedal is disturbingly hard, and also slow to engage.

The slave cylinder is new, with a new seal. The master is not, but before the change the pedal weight was normal. The hose is probably reasonably old. I have a good return spring fitted.

I've bled the system thoroughly, but that didn't help.

It feels very much like a hydraulic restriction -- it takes more effort to disengage the clutch, and it is slow to reengage which causes slippage under power after a gearchange... but with reduced backpressure on the slave cylinder (i.e. unbolted from the car and separated from the clutch arm) the pedal is quite light which casts doubt on that theory.

Has anyone here had this problem? Any suggestions as to the possible causes? My greatest concern is that the increased pressure required to disengage the clutch will cause premature excessive crank float, and I'd kinda like to avoid that

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Simon

The adventures of an owner builder in the Tallarook Ranges

sounds like a problem i had over here with a verto clutch
the friction plate's tooth ring that match the primary gear, what ever its called, was poorly machined that it couldn't move at all. you could press the pedal once and the clutch wouldn't engage again.
even heard of some that wouldn't fit the primary gear at all, all were made by the same manufacturer

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Rover 214 atm ....

don't know much about mechanics, but you could use it to build up your leg muscles

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Yeah, I'm not afraid of a heavy clutch per se.. otherwise I wouldn't have a Mini The thing that gets me is that the clutch is slow to re-engage when you take your foot off the pedal, which it never used to do. That, coupled with the weight of it makes me suspect something ain't quite right... I just can't for the life of me figure out what that is.

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Simon

The adventures of an owner builder in the Tallarook Ranges

I would be fixing this problem as soon as possible - a heavy clutch is pretty normal on a Mini, but it should not be slow to return, the clutch diaphragm should make it return quickly. Sounds like something is binding somewhere, first up I would pull the clutch arm off and check for anything amiss, but it is sounds like something internal which will necessitate pulling the clutch apart. Maybe the diaphragm isn't square, or the bolts aren't seated properly which would buckle the drive straps and could cause the drag you're experiencing - but if this had happened you would probably have significant clutch shudder as well. This is largely conjecture as you wouldn't know until you've pulled things apart.

By the way, when you depress the clutch do the engine revs drop?

Yeah, that's my suspicion. The clutch arm came off and was thorougly cleaned, lubed and reassembled when I changed the friction plate, so it's unlikely to be that.



No clutch shudder at all, it's just slow to return which lends to slippage after a quick gearchange.



Nope, not that I remember.

The only thing I can think is Klas may be close and the friction plate is binding on the primary gear. That didn't get any grease when things went back together, but I really wouldn't have expected that to make such a massive difference. I don't remember which brand it was, but I think it was reputable -- B&B, or PBR, or something like that. Whatever Autobarn supply in their rebuild kit

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Simon

The adventures of an owner builder in the Tallarook Ranges

You aren't supposed to grease the clutch splines anyway. I've never had any problems with clutch splines on cheaper clutch drive plates, except when they separate themselves from the rest of the plate, but that wouldn't cause the problems you're experiencing

Also I would still not totally disregard that the clutch hose could be knackered, if it is old or unknown it may be worth just changing it anyway.

Yeah, that's an unknown. I have a nice new shiny braided item which will go on next week

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Simon

The adventures of an owner builder in the Tallarook Ranges

It is the hose. Don't bother looking at anything else, it is the hose.
They swell up internally and eventually block up completely. You can press it and fluid will go through but with a very hard pedal and then it will only return slowly.

But think about it... If your clutch hose is stuffed, how are your brake hoses?

I agree that its most likely the hose. I had one that was split internally and didn't look like anything was wrong.

Daniel

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Videos - Turbocharged A-Series on Dyno & at Wakefield
Mafs waz not my strong subgeckt at skkol

yea, change the hose, i learned this lesson the expensive way! new master $130, new slave $45, skinned knuckles - pita, still no clutch. new hose $24, problem solved. many wasted hours.

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speed costs....how fast do you want to go...

What they all said ^^^, I had this prob too.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Awesome guys, thanks for the replies. I was basically down to two possibilies -- either the hose is knackered, or the friction plate is binding on the primary gear splines. Strange that the hose would fail all of a sudden following a disassembly/reassembly of the clutch though..

Like I said before, I've got a nice shiny new braided hose to go on the car, so I'll fit that next week and report back.



The brake hoses have all been done reasonably recently, so they're fine. I'm doing a disc conversion next week either way, so they're getting changed again with brand new braided hoses

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Simon

The adventures of an owner builder in the Tallarook Ranges

Guys,

You bloody legends! Changed the clutch hose this morning and gave it a thorough bleed, and I've never felt such a smooth clutch pedal on a Mini. Not too heavy, not too light.. perfect. Haven't driven the car yet, but standing still the clutch action is sweeeeet.

Thanks for the tip, bloody brilliant.

-- Simon

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Simon

The adventures of an owner builder in the Tallarook Ranges