classic car forum header
Classic cars forum & vehicle restoration.
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
How To Register     Posting Photographs     Privacy Policy     F/book facebook.com/oldclassiccar

Super Minx clutch losing pressure
Goto page Previous  1, 2, 3, 4, 5, 6, 7, 8, 9, 10  Next
Post new topic   Reply to topic    Classic cars forum & vehicle restoration. Forum Index -> Rootes Group & Original Companies (Hillman, Humber, Singer, Sunbeam, Commer etc)
Author Message
MrWhite



Joined: 09 May 2017
Posts: 88

PostPosted: Fri Aug 11, 2017 10:24 pm    Post subject: Reply with quote

Sorry I don't know the answer to your problem but I have a Super minx and very interested what could cause this.
Does your car have a servo fitted for the brakes, I don't think it would have been fitted from new but some were added later, wondering if this could have anything to do with your problems but that's my best, somewhat un-technical guess for the moment Rolling Eyes
Back to top
View user's profile Send private message
TriciaS



Joined: 17 Nov 2016
Posts: 62

PostPosted: Fri Aug 11, 2017 11:00 pm    Post subject: Reply with quote

MrWhite wrote:
Sorry I don't know the answer to your problem but I have a Super minx and very interested what could cause this.
Does your car have a servo fitted for the brakes, I don't think it would have been fitted from new but some were added later, wondering if this could have anything to do with your problems but that's my best, somewhat un-technical guess for the moment Rolling Eyes

Hi,
No, does not have servo fitted, I am sure it is air seeping in somehow but still don't understand why the difference in engine on or off
Back to top
View user's profile Send private message
peterwpg



Joined: 10 Apr 2008
Posts: 2223
Location: New Brunswick. Canada

PostPosted: Sat Aug 12, 2017 12:43 am    Post subject: Reply with quote

TriciaS wrote:
peterwpg wrote:
Perhaps look at the clutch lever travel.

Under the vehicle,

#1 Engine off. 1 push, Measure the furthest travel point on the lever with engine off. Keep pedal down for 30sec to 1 minute, does the lever move back ?

#2 Engine off multiple pushes, stop with pedal down , measure as in #1.

#3. Same routine but with engine running.

With hard data it may be possible to recognise the problem and then solve it.

If the clutch lever is moving the same distance under all conditions then, the problem is other than the hydraulics.



ok, done tests today.
1. Engine off measures 6 inches
2. push pedal measures 7 inches
3. hold for 1 minute still 7 inches
4. 8 pumps measures 7 inches
5. hold for 1 minute still 7 inches

6. Engine on measures 2 1/4 inches
7. push pedal measures 2 1/2 inches
8. hold for 1 minute still 2 1/2 inches
9. 8 pumps measures 2 1/2 inches
10. hold for 1 minute still 2 1/2 inches


Logic.??? The engine running causes the arm to reduce its travel by 3.5 to 4.0 ish, inches. ?

If you push the clutch pedal right down and hold it there, then start the engine, what the heck happens to the clutch lever, ? i.e the bit poking out of the bell housing ? does it push back against the slave cylinder. ?

I don't know about anyone else on OCC, but what you describe appears to defy the logical operation of a clutch.

I have had Mini's (1960's 70's) where slave and/or master cylinders were not 100% and needs must (until payday) a rapid cadance operation of the clutch would push the piston out far enough to get a half decent gear change or a degree of control for standing starts.

I am thinking along the lines of something weird with the clutch/thrust bearing setup....

At the risk of being really annoying. 100% sure that the hydraulic connection between the master and the slave is direct, can be seen 100% of its route. I can't think of any reason why it wouldn't.
_________________
Peter L
Back to top
View user's profile Send private message Send e-mail
TriciaS



Joined: 17 Nov 2016
Posts: 62

PostPosted: Sat Aug 12, 2017 8:15 am    Post subject: Reply with quote

Logic.??? The engine running causes the arm to reduce its travel by 3.5 to 4.0 ish, inches. ?

If you push the clutch pedal right down and hold it there, then start the engine, what the heck happens to the clutch lever, ? i.e the bit poking out of the bell housing ? does it push back against the slave cylinder. ?

I don't know about anyone else on OCC, but what you describe appears to defy the logical operation of a clutch.

I have had Mini's (1960's 70's) where slave and/or master cylinders were not 100% and needs must (until payday) a rapid cadance operation of the clutch would push the piston out far enough to get a half decent gear change or a degree of control for standing starts.

I am thinking along the lines of something weird with the clutch/thrust bearing setup....

At the risk of being really annoying. 100% sure that the hydraulic connection between the master and the slave is direct, can be seen 100% of its route. I can't think of any reason why it wouldn't.[/quote]

Ok,
First I have to apologise for being old and not up to date with the type of talk, please simplify your reply as in explain meaning of your question marks and does cadence mean pressing, in short, is there an answer here or just more questions
Back to top
View user's profile Send private message
peter scott



Joined: 18 Dec 2007
Posts: 5981
Location: Edinburgh

PostPosted: Sat Aug 12, 2017 8:48 am    Post subject: Reply with quote

Bitumen Boy wrote:
I wonder if the crankshaft could be moving when the clutch is operated? Probably wouldn't happen with the engine off, but running and lubricated it may be much more free to shift. Can you get an assistant to watch the crank pulley while you operate the clutch, see if there's any fore and aft movement? Also try prying the crank pulley with the engine off. I don't know these Rootes engines at all but on a Triumph with similar symptoms I would suspect dropped crankshaft thrust washers as a possible cause.


I'm inclined to agree with BB. Go under the bonnet and push or lever the crankshaft pulley backwards. Then still under the bonnet start the engine using the button on the starter solenoid and watch the crankshaft pulley. If it moves forward then thrust washers are your problem.

The thrust washers on your engine are located either side of the centre main bearing and you can access them after removing the bearing cap and slide them round the shaft to remove or refit.

Peter
_________________
http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 litre saloon


Last edited by peter scott on Sat Aug 12, 2017 9:02 am; edited 3 times in total
Back to top
View user's profile Send private message Visit poster's website
peterwpg



Joined: 10 Apr 2008
Posts: 2223
Location: New Brunswick. Canada

PostPosted: Sat Aug 12, 2017 8:54 am    Post subject: Reply with quote

Tricias. I am 71+ and consider myself "life experienced", I haven't reached old age yet. Smile

Cadence, Definition a regular beat or rhythm. In pre antilock brake days, a rapid on-off application of the brake especially when driving in the wet.

Also, with the early Minis, to compress the air in order for the brakes to work.

I will admit that my previous reply created , for me anyway, more questions than answers, because the 4" difference in travel defies the mechanical logic of the clutch.

So I did ask two specific questions. Now 3. Smile

1: Is the hydraulic pipe from the master cylinder to the slave, without any other device or connection.

2: Does the brake pedal connect direct to the master cylinder push rod, without any other device or connection.

3: Your earlier reply, gives the travel distance of the clutch arm without the engine running. If you hold down the pedal, you say it doesn't move back.
So... if it is held down and observed, does it move back to the shorter 2" position when the engine is started ? Your reply gives the shorter distance with the engine running but doesn't say that you have seen it move back at the point when the engine is started.

Also see reply from BB and Peter Scott. I too am thinking that something is moving once the engine starts. It doesn't take much movement at the clutch plates to go from grip to no grip.

Another thought is the thrust bearing, but I would expect to actually hear something. The bearing is there to remove the friction between the non rotating clutch arm and the rotating clutch.

I trust I have explained myself a little better.
Regards
Peter.
_________________
Peter L
Back to top
View user's profile Send private message Send e-mail
TriciaS



Joined: 17 Nov 2016
Posts: 62

PostPosted: Sat Aug 12, 2017 9:46 am    Post subject: Reply with quote

peterwpg wrote:
Tricias. I am 71+ and consider myself "life experienced", I haven't reached old age yet. Smile

Cadence, Definition a regular beat or rhythm. In pre antilock brake days, a rapid on-off application of the brake especially when driving in the wet.

Also, with the early Minis, to compress the air in order for the brakes to work.

I will admit that my previous reply created, for me anyway, more questions than answers, because the 4" difference in travel defies the mechanical logic of the clutch.

So I did ask two specific questions. Now 3. Smile

1: Is the hydraulic pipe from the master cylinder to the slave, without any other device or connection.

2: Does the brake pedal connect direct to the master cylinder push rod, without any other device or connection.

3: Your earlier reply, gives the travel distance of the clutch arm without the engine running. If you hold down the pedal, you say it doesn't move back.
So... if it is held down and observed, does it move back to the shorter 2" position when the engine is started ? Your reply gives the shorter distance with the engine running but doesn't say that you have seen it move back at the point when the engine is started.

Also see the reply from BB and Peter Scott. I too am thinking that something is moving once the engine starts. It doesn't take much movement at the clutch plates to go from grip to no grip.

Another thought is the thrust bearing, but I would expect to actually hear something. The bearing is there to remove the friction between the non-rotating clutch arm and the rotating clutch.

I trust I have explained myself a little better.
Regards
Peter.


ok, the crankshaft has no movement at all, looked whilst pressing pedal and engine off, I will try again today or tomorrow for movement with the engine on, I will also see what happens to rod when clutch pressed and held then engine turned on, the short rapid pressing of the clutch will bring pressure back but only once each time, I must also say see my name I am female not quite a blond but almost, please explain things in old woman language as I cannot actually drive myself but do all the reading for fixing, I am normally not allowed to turn the key haha.
ooh forgot to add nothing extra connected to system either brake or clutch, 2 separate pots of fluid and no servo's or other contraptions fitted anywhere
oh so can anyone else let me know what sort of movement their slave push rod has so I have something to compare to
Back to top
View user's profile Send private message
peter scott



Joined: 18 Dec 2007
Posts: 5981
Location: Edinburgh

PostPosted: Sat Aug 12, 2017 12:28 pm    Post subject: Reply with quote

TriciaS wrote:
so can anyone else let me know what sort of movement their slave push rod has so I have something to compare to


The last time I owned a Rootes car with hydraulic clutch was more than 40 years ago so excuse my description from distant memory. I would expect the clutch operating lever to flop about in the absence of a return spring but as you move it backwards you should feel the release bearing come in contact with the clutch and from that point I would not expect the slave cylinder to push the lever by more than about one inch further back to actually operate the clutch.

Peter
_________________
http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 litre saloon
Back to top
View user's profile Send private message Visit poster's website
peterwpg



Joined: 10 Apr 2008
Posts: 2223
Location: New Brunswick. Canada

PostPosted: Sat Aug 12, 2017 12:31 pm    Post subject: Reply with quote

Here is part of Tricias first post.

I have a Hillman Super Minx MKIV and it had a new clutch fitted shortly before I purchased it but the slave needed doing so I have replaced with a new slave cylinder, now a new problem I bleed all the air out and it seems fine but then I start engine and the pedal goes halfway down before getting firm, I have tried bleeding again and again but still the same problem, I did notice the new slave was slightly longer than the old

I think it would be a good idea to go to the beginning.

1: Who replaced the clutch.
2: Did it drive when first purchased
3: Was the original problem only that the pedal had to be pumped for the clutch to work to allow a standing start

I am wondering if we are being distracted by the term "getting firm" , from the measurements, it appears the clutch actuator is moving and a clutch doesn't need much movement.

Does "getting firm" mean that the pedal won't go down any further but hasn't yet reached the floor or whatever stop there may be.

The bite and release point of the clutch should be somewhere midway between the pedal at rest or right to the floor/stop. The clutch and clutch operating system, in this case hydraulics, should prevent the clutch disengage mechanism from being moved further than it should.

With respect, I have no idea of your mechanical knowledge as related to a vehicle's clutch.

What I refer to as over extension of the clutch, whether it be caused by the wrong clutch, wrong bearing, wrong operating system, etc, can damage the clutch and possibly other components. The comment about the new "longer" slave cylinder and spacer ? may be a clue.

It is of course quite possible that the master cylinder is faulty, but at the moment this thread does not show if the vehicle is drivable.
_________________
Peter L
Back to top
View user's profile Send private message Send e-mail
peterwpg



Joined: 10 Apr 2008
Posts: 2223
Location: New Brunswick. Canada

PostPosted: Sat Aug 12, 2017 12:33 pm    Post subject: Reply with quote

peter scott wrote:
TriciaS wrote:
so can anyone else let me know what sort of movement their slave push rod has so I have something to compare to


The last time I owned a Rootes car with hydraulic clutch was more than 40 years ago so excuse my description from distant memory. I would expect the clutch operating lever to flop about in the absence of a return spring but as you move it backwards you should feel the release bearing come in contact with the clutch and from that point I would not expect the slave cylinder to push the lever by more than about one inch further back to actually operate the clutch.

Peter


No mention of a spring, is there one ?
_________________
Peter L
Back to top
View user's profile Send private message Send e-mail
TriciaS



Joined: 17 Nov 2016
Posts: 62

PostPosted: Sat Aug 12, 2017 1:16 pm    Post subject: Reply with quote

peterwpg wrote:
Here is part of Tricias first post.

I have a Hillman Super Minx MKIV and it had a new clutch fitted shortly before I purchased it but the slave needed doing so I have replaced with a new slave cylinder, now a new problem I bleed all the air out and it seems fine but then I start engine and the pedal goes halfway down before getting firm, I have tried bleeding again and again but still the same problem, I did notice the new slave was slightly longer than the old

I think it would be a good idea to go to the beginning.

1: Who replaced the clutch.
2: Did it drive when first purchased
3: Was the original problem only that the pedal had to be pumped for the clutch to work to allow a standing start

I am wondering if we are being distracted by the term "getting firm" , from the measurements, it appears the clutch actuator is moving and a clutch doesn't need much movement.

Does "getting firm" mean that the pedal won't go down any further but hasn't yet reached the floor or whatever stop there may be.

The bite and release point of the clutch should be somewhere midway between the pedal at rest or right to the floor/stop. The clutch and clutch operating system, in this case hydraulics, should prevent the clutch disengage mechanism from being moved further than it should.

With respect, I have no idea of your mechanical knowledge as related to a vehicle's clutch.

What I refer to as over extension of the clutch, whether it be caused by the wrong clutch, wrong bearing, wrong operating system, etc, can damage the clutch and possibly other components. The comment about the new "longer" slave cylinder and spacer ? may be a clue.

It is of course quite possible that the master cylinder is faulty, but at the moment this thread does not show if the vehicle is drivable.


The engine has supposedly had a rebuild the year before I purchased the car, the new clutch was also fitted before I purchased the car but the previous owner said the clutch pedal was spongy and sometimes difficult to engage gear, we have not had it on the road properly but when tested on a short journey the clutch seemed to go into gear but pedal spongy as I say I do not drive so can only say what my other half tells me about the problems then I look it up and tell him what to fix, we decided to get a new slave as the old one's piston was very corroded and hardly moved in the bore.

getting firm just means it is firmer to push but still does go on to the floor but first half of travel is like no pressure at all, yes there is a return spring, whoever fitted the clutch had put the slave on the wrong side of the bell housing so the spring was stretched and a bit snapped off, something else I am looking for a replacement but it fits now the new slave is on the other side of the bell-housing as when my partner put the new slave in the same way the old came off the piston was almost coming out of the bore.
Back to top
View user's profile Send private message
peterwpg



Joined: 10 Apr 2008
Posts: 2223
Location: New Brunswick. Canada

PostPosted: Sat Aug 12, 2017 2:03 pm    Post subject: Reply with quote

Hello Tricia. I speak for myself here, other OCC members may feel different.

From what you have said I honestly believe that the problems and cure may well be outside of your combined knowledge and skill levels.

There was a problem with the clutch when you purchased the car and it had previously undergone an engine rebuild.

The comment about the slave cylinder on the "wrong side" has me perplexed but I am sure that someone with better knowledge of your vehicle could understand.

Personally I am not sure that the problems can be fixed via OCC postings. Your profile does not give your location, if you could add that, the nearest town/village is sufficient, then perhaps the OCC members in your locality could advise on someone local to you who may be able to assist.

Looking back at your earlier 2016 postings, is this the same car, with overdrive, it would seem you inherited a number of minor problems.

I hope things work out and please keep OCC informed of your progress.

Best regards

Peter
_________________
Peter L
Back to top
View user's profile Send private message Send e-mail
TriciaS



Joined: 17 Nov 2016
Posts: 62

PostPosted: Sat Aug 12, 2017 3:50 pm    Post subject: Reply with quote

peterwpg wrote:
Hello Tricia. I speak for myself here, other OCC members may feel different.

From what you have said I honestly believe that the problems and cure may well be outside of your combined knowledge and skill levels.

There was a problem with the clutch when you purchased the car and it had previously undergone an engine rebuild.

The comment about the slave cylinder on the "wrong side" has me perplexed but I am sure that someone with better knowledge of your vehicle could understand.

Personally I am not sure that the problems can be fixed via OCC postings. Your profile does not give your location, if you could add that, the nearest town/village is sufficient, then perhaps the OCC members in your locality could advise on someone local to you who may be able to assist.

Looking back at your earlier 2016 postings, is this the same car, with overdrive, it would seem you inherited a number of minor problems.

I hope things work out and please keep OCC informed of your progress.

Best regards

Peter


I will just add we have had lots of classic cars in our 27 years together and always managed to sort out the problems but so far never had to delve into the bottom end of engines so will not start doing that now, I am sure it just needs either a master cylinder or more bleeding but would still like to know from anyone else with a super minx what the travel of the push rod is so as I know what sort of problem I have, I will not give up yet, I do prefer clutch's with manual linkage and cable rather than fluid but will persevere
Back to top
View user's profile Send private message
alastairq



Joined: 14 Oct 2016
Posts: 1085
Location: East Yorkshire

PostPosted: Sat Aug 12, 2017 4:16 pm    Post subject: Reply with quote

An easy way to discover what 'travel' there should be, is to crawl underneath...preferably with something to act as a pry-bar?

Probably best to remove the push rod which the slave cylinder will bear on...then, using the lever against something, push the clutch actuating arm[probably backwards..the thrust bearing will have to travel forwards to contact the clutch fingers [or diaphragm]...].....to feel where it contacts the clutch itself. Then at that point [with a big enough lever, or shove]....press a bit harder, and you should feel the pressure of the clutch disengaging.

Once the movement is made, it ought to be possible to detect, by feel, if the clutch mechanism inside the bellhousing, is operating correctly. It is entirely possible the thrust bearing has become dislodged from its place, inside the bellhousing? Even if only on one side?

The amount of movement to first contact, then, to opening the clutch, will give you some idea of how much movement the slave has to impart?

I, too, struggle to comprehend how the original fitment of the slave was 'on the wrong side?'

Another thought has occurred.....did whoever fitted the clutch actually use the correct bit [clutch] for that engine & gearbox? If the clutch that was fitted, is ''too thin'' for that engine/ gearbox, then the clutch release mechanism will struggle to reach, inside the bellhousing. [Some clutch covers are quite a bit deeper than others...ie, more dished??]

Hence why I, and others, have suggested pulling the engine/gearbox apart, to go back to basics?
Back to top
View user's profile Send private message
TriciaS



Joined: 17 Nov 2016
Posts: 62

PostPosted: Sat Aug 12, 2017 7:00 pm    Post subject: Reply with quote

alastairq wrote:
An easy way to discover what 'travel' there should be, is to crawl underneath...preferably with something to act as a pry bar?

Probably best to remove the push rod which the slave cylinder will bear on...then, using the lever against something, push the clutch actuating arm[probably backwards..the thrust bearing will have to travel forwards to contact the clutch fingers [or diaphragm]...].....to feel where it contacts the clutch itself. Then at that point [with a big enough lever, or shove]....press a bit harder, and you should feel the pressure of the clutch disengaging.

Once the movement is made, it ought to be possible to detect, by feel, if the clutch mechanism inside the bell-housing, is operating correctly. It is entirely possible the thrust bearing has become dislodged from its place, inside the bell-housing? Even if only on one side?

The amount of movement to first contact, then, to opening the clutch, will give you some idea of how much movement the slave has to impart?

I, too, struggle to comprehend how the original fitment of the slave was 'on the wrong side?'

Another thought has occurred.....did whoever fitted the clutch actually use the correct bit [clutch] for that engine & gearbox? If the clutch that was fitted, is ''too thin'' for that engine/ gearbox, then the clutch release mechanism will struggle to reach, inside the bell-housing. [Some clutch covers are quite a bit deeper than others...ie, more dished??]

Hence why I, and others, have suggested pulling the engine/gearbox apart, to go back to basics?


the meaning of the slave being on the wrong side means that as you have the lip of the bell-housing with the 2 bolt holes you can either put the slave in front or behind the lip plus there is a spacer, it was fitted with the spacer and slave on the same side which was in front of the lip, as our new slave was a tad longer we have put the slave and spacer on opposite sides as when the slave was on the front the piston came out too far, anyway I am not going to delve into taking the gearbox off as the car does go into gear so I cannot see any problem with the workings or type of clutch fitted, I am still thinking it is a fluid leak or air intake somewhere, I really want to know of some other measurements of engine on and off as in movement of the push rod or it was a pointless exercise on my part as it did not solve anything.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    Classic cars forum & vehicle restoration. Forum Index -> Rootes Group & Original Companies (Hillman, Humber, Singer, Sunbeam, Commer etc) All times are GMT + 1 Hour
Goto page Previous  1, 2, 3, 4, 5, 6, 7, 8, 9, 10  Next
Page 2 of 10

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
Forum T&C


php BB powered © php BB Grp.