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Clutch Problem Mini Spi 1993


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#16 Crawfish

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Posted 16 February 2021 - 09:08 PM

Opening the bleed screw and trying the pedal will get you to an answer sooner, and will rule out the clutch hydraulics as the potential issue. In my case I was in no hurry with my car as it had been off the road so long the clutch wasn’t high on my to do list, so could afford to wait on the hunch the clutch plunger/arm was seized (often is the case).

 

The clutch pedal is mechanically connected to the clutch master cylinder which in turn is connected to the slave cylinder (the bit the clutch arm is connected to), these are connected via a metal pipe and a rubber hose. Normally as you push the clutch pedal pressure is built up in the system (via the clutch master cylinder - think of this as a pump) which forces brake fluid down the pipe and hose into the clutch slave cylinder, the slave cylinder then pushes the rod outwards which operates the clutch arm. If you have a blockage in the clutch hydraulics (eg collapsed hose etc), then the pedal could go rock hard (think of putting your thumb over a hose pipe - the pressure builds up and it has nowhere to go).

 

I myself in 12 years of being around/working on Minis have never come across an issue with clutch hydraulics causing a rock hard pedal (usually pedal goes soft - clutch drag), but I’m not saying it can’t happen, so would be well worth ruling this out.

 

There is a potential of introducing air into the clutch hydraulics, so some precautions to avoid this can be taken. This is not the end of the world however as the clutch hydraulics are easy to bleed if needed.

 

Either have a helper press the pedal for you, or as I do find a piece of 4x2 or similar cut to size and wedge the pedal down wedging the wooden block between the pedal and seat (or cross member)

 

  • First open the bleed screw on the clutch slave cylinder, you only need to open this like 1/2 a turn.
  • Ask you assistant (or using the piece of wood) press the clutch pedal down
  • Wait a second or so while some fluid is expelled.
  • Tighten the bleed screw while the pedal is still pressed down.
  • Once bleed screw has been tightened release the clutch pedal

 

If you find after trying the above the pedal goes down, but after tighten the bleed screw on the clutch slave the pedal goes hard again and can’t be pressed you know the issue is mechanical (likely seized clutch plunger/arm). If however the clutch pedal remained hard with the bleed screw open (in this case you may not see brake fluid expelled from the bleed screw when the pedal is pressed) then you know the issue is with the hydraulics.

Thanks for the very detailed explanation written in terms I understand .

I think I will continue to try the method of not turning the bleed screw for a few more days ,then if that doesn't work I will follow the instructions with someone helping me on the pedal.

 

Really appreciate the time you have taken and will return when I get to the next hurdle or success, might be a week or so 

many thanks



#17 Crawfish

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Posted 17 February 2021 - 02:52 PM

Not sure if this will make much difference to you guys visually, but Ive got ambitious and have been using my new socket set and removed yet more car parts.

Attached is a picture of my actual car.

 

As has been mentioned before the two nuts are flush with the Wok instead of there being a gap and the rest of it is clear to see.

 

Not sure if this is revealing in anyway ,but thought it worth posting, even just to show the condition of the parts

 

Cheers

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#18 sonscar

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Posted 17 February 2021 - 03:03 PM

Read what I wrote.Nuts tight on wok,clutch stuck disengaged.Open bleedscrew and persuade them back out.Steve..

#19 Norris73

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Posted 17 February 2021 - 04:08 PM

As Steve has already said the clutch looks to be stuck disengaged. Open the bleed screw ½ a turn or so and try to pull the throw out nuts at the end of the wok back out (may be easier if you grab the top of the clutch arm and try to push it back towards the clutch slave, this will have the same effect). You should have a good gap of a few millimetres from the inner nut and the end of the wok, once you have this gap close the bleed screw and try the pedal.

 

Does seem to be plenty of rusty marks at the clutch arm pivot point, and the clutch slave rod seems to have some rusty muck as it appears from the rubber dust boot. It’s possible the slave cylinder is past its best and leaking brake fluid (you can check by peeling the rubber dust boot off and looking/feeling for dampness which would indicate brake fluid leaking past the seals), but check that once you have things freed off.

 



#20 Crawfish

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Posted 17 February 2021 - 04:21 PM

Read what I wrote.Nuts tight on wok,clutch stuck disengaged.Open bleedscrew and persuade them back out.Steve..

Hey Steve , The post was just confirming what you had said earlier about the nuts being tight (as you said they would be) next step will be bleedscrew :)



#21 Crawfish

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Posted 17 February 2021 - 04:23 PM

As Steve has already said the clutch looks to be stuck disengaged. Open the bleed screw ½ a turn or so and try to pull the throw out nuts at the end of the wok back out (may be easier if you grab the top of the clutch arm and try to push it back towards the clutch slave, this will have the same effect). You should have a good gap of a few millimetres from the inner nut and the end of the wok, once you have this gap close the bleed screw and try the pedal.

 

Does seem to be plenty of rusty marks at the clutch arm pivot point, and the clutch slave rod seems to have some rusty muck as it appears from the rubber dust boot. It’s possible the slave cylinder is past its best and leaking brake fluid (you can check by peeling the rubber dust boot off and looking/feeling for dampness which would indicate brake fluid leaking past the seals), but check that once you have things freed off.

Cheers ,It's always useful to see an actual picture of what we are talking about ,I'll have a go at the bleedscrew (hopefully tomorrow) and will let you guys know what happened 



#22 northernboy

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Posted 17 February 2021 - 05:25 PM

Take lots of photos as you go, it will help when it comes to re assembling everything.

 

If there is no movement after the bleed screw is slackened off, you could try to remove the slave cylinder completely ( two bolts) as this is on a flexi you can just put to one side. The rod should pull out of the slave cylinder but you may loose some brake fluid so have cloths ready as brake fluid eats paint. 

 

New slave cylinders are cheap and not really worth trying to repair.

 

Once the slave cylinder is out of the way you are just left with mechanical things.

 

See if the arm or plunger moves - try gentle tapping with a hammer but don't get too carried away.

 

Using two spanners, try to loosen off the lock nut (the outer nut) and then try to loosen off the flange nut.

 

Now see if the plunger moves one way or another  (this is probably the most likely culprit) - as has been said leave it to soak and gentle tapping the WOK and plunger with a hammer and hope it becomes free - it may take a while. 

 

If the plunger is still stuck solid, then the next thing is to remove the WOK - this is held on with a number of bolts but two or three at the bottom are really hard to get at ( but not impossible with determination).



#23 Crawfish

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Posted 17 February 2021 - 06:31 PM

Take lots of photos as you go, it will help when it comes to re assembling everything.

 

If there is no movement after the bleed screw is slackened off, you could try to remove the slave cylinder completely ( two bolts) as this is on a flexi you can just put to one side. The rod should pull out of the slave cylinder but you may loose some brake fluid so have cloths ready as brake fluid eats paint. 

 

New slave cylinders are cheap and not really worth trying to repair.

 

Once the slave cylinder is out of the way you are just left with mechanical things.

 

See if the arm or plunger moves - try gentle tapping with a hammer but don't get too carried away.

 

Using two spanners, try to loosen off the lock nut (the outer nut) and then try to loosen off the flange nut.

 

Now see if the plunger moves one way or another  (this is probably the most likely culprit) - as has been said leave it to soak and gentle tapping the WOK and plunger with a hammer and hope it becomes free - it may take a while. 

 

If the plunger is still stuck solid, then the next thing is to remove the WOK - this is held on with a number of bolts but two or three at the bottom are really hard to get at ( but not impossible with determination).

Thanks for all the advice, photos are definitely useful to reassembly and I am taking them as I go.

 

I'm really not the right person to go too far with this ,but I can follow as far as what I'm comfortable with, it's good to know a specific order things should be done in ,even if it comes to me paying someone to do it for me eventually.

 

I'm a great believe in replacing entire parts ,as they are relatively cheap and the slave cylinder I'd like to change anyway ,regardless of wether its the culprit or not as its getting old.

 

Annoyingly.... I thought I'd nip to the garage and see if I can move the bleed nut and it won't budge!! (I'm going anti clockwise with it ) 

I've put some WD40 on it , Is this normal with bleed nuts?



#24 northernboy

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Posted 17 February 2021 - 07:14 PM

Yes - anti clockwise to undo the bleed screw - again apply WD40 and go very gently - ensure you use a correct size ring spanner or small socket - work it anticlockwise - clockwise to try and fee it - it it works loose great, but if it snaps (and it may as they are not very strong) - the just replace the whole unit.



#25 Crawfish

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Posted 17 February 2021 - 07:23 PM

Yes - anti clockwise to undo the bleed screw - again apply WD40 and go very gently - ensure you use a correct size ring spanner or small socket - work it anticlockwise - clockwise to try and fee it - it it works loose great, but if it snaps (and it may as they are not very strong) - the just replace the whole unit.

Thanks again ,

Tomorrow I'm going to buy some Plusgas as Norris73 advised me to a few days ago.

 it will mean I can spray it on the other parts as well as this nut and hopefully will make all of them able to move.

 

I'm going to try hard not to break the nut ,I'm getting close to breaking the car windscreen with a hammer though!



#26 Crawfish

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Posted 19 February 2021 - 06:45 PM

Hi all

I'm attaching the picture that I've already posted as a point of reference for you.

 

Today the same mechanic came back round and seeing as he hadn’t seen the car since the last time and at that time it had an ECU and the horn in the way. This time he could see the Slave cylinder/ Nuts on the Wok/ etc

 

I’ll try and tell you what he said./diagnosed and how he went about it

 

Bear in mind most of it I didn’t understand as I’m not mechanically minded and you might have to fill in the gaps but I'll put down here what I remember

 

Firstly he said that the arm looked like it was at its maximum extension, which he said meant it was probably the clutch itself ,not the slave cylinder, as the arm had gone in too far (into what too far I can't remember)

 

He then tried starting the car in 1st gear and it wouldn’t drive ,which was also was a reasoning it was the clutch itself that was a problem (not sure why).

 

I had to persuade him to loosen off the bleed screw and try and jemmy the parts loose as you guys recommended, after doing this he mentioned you could now see the arm wasn’t jammed as it was moving - to my eyes it wasn’t moving very far ,but it was certainly moving ,which it wasn't before this

 

He seemed to be pretty definite it was the clutch and recommended I bought a clutch kit to replace all of it ,as there was a lot of work involved in changing a bit of it ,you might as well change all of it which also makes sense to me.

 

He asked me if the clutch had been making any noises before the event or not working very well. Neither of these was the case ,the clutch was working fine

 

His words with what was wrong was the bearing has gone into the diaphragm and I think he said the clutch was jammed open.

 

I'd be interested what you guys reckon ,

On the upside I now can open the bleed screw up ,if anyone has any ideas there

 

Cheers

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#27 sonscar

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Posted 19 February 2021 - 06:49 PM

The clutch is still operated in that photo,there should be approx 6mm between the nuts and wok.Steve..

#28 Crawfish

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Posted 19 February 2021 - 07:28 PM

The clutch is still operated in that photo,there should be approx 6mm between the nuts and wok.Steve..

Does that mean what he is saying is incorrect? Should the gap you mention have reappeared after he opened the bleed valve and attempting to pry the bar free? Did he not release it properly?



#29 sonscar

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Posted 19 February 2021 - 09:15 PM

There indeed should be a gap,operating the clutch closes the gap.The nuts stop the clutch going too far.He could easily be mistaken.I am cautiously advising to get a long screwdriver and tap it between the wok and nuts.Do this carefully and at your own risk.Steve..

#30 Crawfish

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Posted 19 February 2021 - 09:46 PM

There indeed should be a gap,operating the clutch closes the gap.The nuts stop the clutch going too far.He could easily be mistaken.I am cautiously advising to get a long screwdriver and tap it between the wok and nuts.Do this carefully and at your own risk.Steve..

Hi Steve,

Thanks for the reply. 

This is tricky for me as with my lack of knowledge, I’m  listening to advice from people who I know ,know a huge amount about minis but I’ve never met and someone who is a paid up mechanic with the van and stuff who seems incredibly certain of whats wrong.

At the moment you guys have the numbers and if you think that I should (cautiously) continue thats fine by me 

 

To be honest if your idea doesn’t work ,whats the worst that can happen?

Am I going to break a clutch thats apparently already broken? or maybe I’m going to save myself hundreds of pounds with some screwdriver tweaking :)

 

The bleed screw has only just become able to use , I’ve had a lot of suggestions from yourself Norris73 Northernboy as to how i might free things up and quite happy to have a go at all of them.

 

 Does the bleed screw have to be left open whilst any tinkering from me is going on?






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