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MG Midget and Sprite Technical - No Clutch

Clutch gone, pedal to the floor, fluid low in clutch master cylinder, master cylinder not leaking, no fluid discernible anywhere.
Returned home behind almost Wolves coloured van.
Topped up master cylinder, a bit more feel at the bottom of the pedal travel but not enough clutch to operate gear change. Fluid level staying full. No leak.

Presumably most likely scenario is the mechanical clutch itself has failed? Engine out?
Dave Squire

Could be the slave cylinder, I find they don't last that long.
Bob Beaumont

get under the car and watch while someone pumps the pedal. is the pushrod moving?
graeme jackson

isn't there a situation with the 1500 where the actuating rod can fall off or displace itself or summat?
David Smith

I don't think the slave can fail without leaking.

Charley
C R Huff

If the cup seal is worn in the MC you will not necessarily lose fluid, but it will not build or hold pressure, so you have no clutch.
dominic clancy

Clutch gone, pedal to the floor, fluid low in clutch master cylinder, master cylinder not leaking, no fluid discernible anywhere.

Sooo ... you did lose fluid ??? Where did it go? Did it decide to go live with jesus ?

Im thinking you got a small hole in the brake line or an ill seated / loose fitting somewhere in the system

Bottom line, brake fluid dosnt just evaporate

Prop
Prop and the Blackhole Midget

David is right, in a 1500 Midget it is possible that the dowel, which the arm that pushes the clutch release bearing against the clutch, pivots on has dropped out. The dowel is normally held in place by a C shaped clip but this can be displaced and the dowel can work itself out. If this has happened the slave may have overextended itself causing the fluid loss into the bellhousing so may not be immediately visable.

Another possibility with the 1500 slave cylinder is that the whole slave can slide back out of the bellhousing by a small amount. It is held in place by a notch in the slave lining up with a bolt which acts like a grub screw against it. If this bolt is worn or the slave cylinder has not been orientated correctly when last fitted, then it is possible for the slave to push back and obviously not provide the correct leverage against the release arm, therefore not actuating the clutch.

On the upside, if it is a 1500 it is possible to remove and replace the slave cylinder with the engine in place. It aint all that much fun but it is definitely possible!

Last thing to check is that you didn't suck any air bubbles into the plastic clutch line which runs to the slave when the fluid was low. Check by the bulkhead as often this is the highest point above the master cylinder, if there are bubbles there it can be a pig to bleed and I would highly recommend investing in a Gunson's Eezibleed, it really does make life a huge amount easier!

Hope this helps

David
D Prince

Dave, it sounds to me as if your clutch lever arm fulcrum pin has dropped out. A fairly common occurrence on 1500s. This would have the effect of little or no "pedal" and also an apparent loss of fluid at the master cylinder, as the slave piston moves forwards in its bore. But no sign of leaks.

The check for this is to reach under the car and see if the pin (driver's side) is still located. If not it is supposed to be a gearbox out job to replace, but can be achieved with some dexterity by pushing a large headed bolt ( 1/2" X 3 1/2" coachbolt will do it, I think) down through the pivot hole in the bellhousing, catching the pivot hole in he clutch arm on the way. May take a bit of jiggling about, but once in it will stay there and work as well as the original.

Edit: Not sure but I think this is what Dave is referring to as well.
Guy Weller

Thanks everyone,

When returned by AA man I filled master cylinder and tried clutch. Still no clutch but a bit of feel at the bottom of the travel.
Left car on drive and wrote first entry to this thread. Sat at my desk muttering and growling between client chats trying to make a day of it.
Just gone out to it now expecting to have to push car into back yard but found clutch working. Started engine and moved car. A bit juddery but working.
Then went back out to look at drive and there is some 'oil' on the drive. Can't tell if its my engine oil leak or brake fluid as engine oil leak cokes off bell housing (ref previous posts earlier in the year) however it could be more than usual. At one point I was sure my oil leak was just the odd spot and this is a little pool where all the other spots are.

Have access to another car in the morning so no need to use Midge so I will crawl under sometime on the morrow and take a closer look.

Will report back then.

Thanks everyone, Dave
Dave Squire

Your description of clutch partially working near the bottom of the pedal stroke, but feeling rough or notchy is still exactly in line with the fulcrum pin having dropped out. Its an easy enough job to check and replace it. You can even do it with an old screwdriver blade
Guy Weller

I get it: The slave could be extended and therefore take more fluid. Must remember the cloth at the master end if it is so when I push it back.

I think you (Guy and David) have covered all the do able bases without taking the engine out. That's definitely my style.

Clutch has been a bit sort of 'worn' lately (sometimes a bit slow/I can beat the box ish) Hence my monikar of replacing the clutch. I thought it had failed last week as I could not change down for a local low speed corner to find that when I had coasted to a stop it worked fine again. The road was rough and so am now thinking it could have jolted the misaligned part back I suppose.

I will check both your suggestions for the slave and fulcrum out in the morning. Would be good to not replace the clutch just yet.
Dave Squire

Re. 1500 Midget clutch fulcrum pin. IMHO, a red herring.
It's my experience that the fulcrum pin is not an essential component for effective action of the clutch. I have a 1976 1500, and, back along, I had covered several thousand miles only to coincidently discover that my fulcrum pin had dropped out a few years prior.I put it down to the self-adjusting nature of the clutch hydraulic system. Perhaps the bell housing/bearing holder design changed after my car year/month production (early 1976), but a flange of the clutch bearing holder nestles in a recess in the bell housing - a relationship that provides its own fulcrum action, with or without the fulcrum pin in place.

Re. clutch slave cylinder.
Unless an incorrect securing bolt, or a missing or inadequately tightened bolt, is in evidence, it's virtually impossible for the slave cylinder to move (by dint of the clamp effect of the bolt and the locating groove in the slave cylinder body).

My money on Dave Squire's problem is leaking clutch fluid, probably from the slave cylinder.
Andy Hock

Dave, if it is the pivot pin it is an 8 mm pin/bolt, I think something like 40 mm long you need. I took a picture of where to look, hang tight...

Malc
M Le Chevalier

pic... follow the torch light!!

M Le Chevalier

When the pin drops out, the clutch lever arm displaces and the effective fulcrum point is shifted so that the arm pivots against the edge of the cut out in the bell housing instead. It will then appear to function correctly again, other than a drop in M/c fluid level. But without the proper pivot it has a tendency to shift laterally, giving a variable mechanical advantage to the clutch operation. So it will work well on one pedal stroke, and only partially disengage the clutch on the next! Makes for an erratic and puzzling driving experience!

I do stand to be proved wrong, but I am just relating my own experience with a very similar set of symptoms when I owned a 1500.
Guy Weller

Thanks for the pic Malc. That's great. I looked under the car yesterday but mine is a mite dirtier than yours and I failed to locate it miserably (and oilylily - if that's a word).
Out to look again in a min with torch.

Suns out, phone quiet, misus not looking? .......
Dave Squire

Thanks Malc that was a lot easier to find out your way than my first attempt and well done Guy; its missing!

Need to find bolt next so in touch again probably tomorrow. Presumably I should put a nylox on the lower end if poss to stop it from working out?

In the mean time the modern will be fixed by tomorrow and we have extended the hire car rental till Monday. The word on the ether is something about pouring and raining :-)

Still smiling, Dave
Dave Squire

Just to be sure Dave... you did try poking something down the hole, right? You can only see mine because I stuck a bolt in the hole and you can see the head. Ordinarily it is a pressed in pin, so there won't be anything really visible and you would have to check with a poker.

Malc.
M Le Chevalier

That's good news Dave. As mentioned, the proper way is to fit a new pin but I am pretty sure that involves taking the engine/gearbox out. Dropping a bolt in from the top instead seems to work well though. I thought I had used a 1/2" coachbolt, but it must have been a thinner one than that. If Malcolm is quoting 8mm it must have been something like 5/16" or maybe 3.8" I know it was imperial and didn't get a nut on the bottom as I couldn't find a nylock to fit and anyway I thought it was a temp fix. Inevitably it remained in use for around 5 years!

Wise words, Malcolm!
Guy Weller

No I didn't Malc but my other earlier (76) bell housing has a bolt in it like yours shows with a nut on the other end. I will get an electrical screw driver or stiff coat hanger wire and poke it in a while.

I think the size may vary Guy as the parts list on Moss shows some bushes as well. I will just have to play it as it goes and if it is the pin the local garage where the modern is being fixed are OK for bolts if I can't find one to fit. Its no more than a 100m walk.

Cheers, Dave
Dave Squire

Car up on stands so I can get underneath.
There is a pin in it.
And the bottom of the bell housing and passenger floor is still covered in black oil from the engine as per always for the last 18 months. The slave cylinder is also covered in this oil. Surely the DoT4 would wash some oil off? Also the level in reservoir not going down when I hold pedal in for a minute or so or washing out anywhere underneath. So looks like the mechanical clutch is failing and I am just being lucky in the yard that it works at all.
Together with the clean oil on the rear of the gear box :-( I would say its engine and box out time unless someone has an ace way of removing gearbox without engine. As I understand it the gearbox mount is on the main floor cross member and needs too much play to remove with engine in car. That is unless of course I cut that and plate a stiffener back in that's bolted like for the front line type 9 conversion or overdrive conversions I have seen at my local MASC. (quite nice).

So Guy should I get on with the cutting or buy a crane?

Feel like cutting; Dave
Dave Squire

I certainly wouldn't cut the car up to get the trans out. And, if you are just doing clutch work I believe you can just remove the engine.

Charley
C R Huff

Ah, that's a pity Dave. The pin dropping out was a real possibility and would have been so much easier to fix! Assume you have ruled out any other causes on the external side of the bellhousing? There were a number of other suggestions that others wee making. If its none of those then it will be engine out time. Its not such a big task once you get started. O most certainly wouldn't start cutting up the floor pan yo get the gearbox out. Not a good ides at all!

Borrow or hire a crane, sort out the tools you will need and have a read of Haynes. Then just get stuck in.
Guy Weller

don't cut! if you are removing engine you have to drain rad... from there it is only a couple of small steps to removing front and getting burly mates to lift engine out forwards!
M Le Chevalier

OK. Don't panic. I was just seeing if I could progress to my 5 speed or overdrive stage being ready at this point to save time and effort later.

My main problem is a PO somewhere along the line made a mess or several messes of the front of the car so there are a lot of welded panels and parts that should be bolted in. If its simply rad out then engine then that's OK cos I fixed it to get the rad out when I did the tensioner and timing cover. If its more than that then I will need to take a lot more time to sort it out.

Have engine crane I can borrow lined up.
Dave Squire

Sounds like the ideal time to go for the overdrive conversion Dave.



So worth doing, I'm sure it would have been a factory option from new if only it hadn't required minor alterations to the floor pan pressing and by that stage the Midget hadn't got long to live and there was no money for that sort of thing.



Far easier and cheaper than the Ford 5 speed option, overdrive gearboxes from Spitfires or Dolomites often come up on e-bay at sensible money.
SR Smith 1

Dave, I have a Type 9 conversion with removable cross member. Pretty sure this still doesn't allow enough space to remove the gearbox from underneath without removing the engine. I think to achieve that you would need to cut out quite a lot more of the underside of the tranny tunnel. I think even if the space could be made, it would be a difficult job to carry out as it can sometimes be tricky enough aligning the gearbox onto the clutch & engine even when out of the car.

For engine removal a significant issue is whether to keep the carbs and manifold attached to lift out with the engine, or whether to disconnect the manifold from the engine and just tie the whole lot back out of the way to give clearance for lifting. Both methods work; which is easiest depends on access and which bolts may be most seized up. And whether you have an aftermarket tubular steel manifold. Access in that area is not easy on a 1500 engine!



PS, and yes, I too am a fan of the overdrive alternative for the 1500 rather than a 5 speed. Much more fun to drive! I wonder what's become of my o/d 1500, sold about 15 years ago!
Guy Weller

having owned a couple of classic British cars with overdrive, the last just before I got my present Midget I'd disagree with having o/d over a 5-speed

with o/d you need to keep a load on with engaging and disengaging the o/d so when you want to slow when in o/d 4th you need to keep load on the accelerator which is counter-intuitive and also means you're not using the engine braking at that stage

I do agree that going from 3rd to o/d 3rd at a flick of a switch is fun but then it leaves you with going into o/d 4th and losing the momentum built or flicking out of o/d and going into 4th all a bit messy

I would favour and recommend a 5-speed over a o/d set up but do understand the possible initial benefits of fitting an o/d over a 5-speed but with use a 5-speed is far better
Nigel Atkins

Have you actually had the slave out and checked it? Tried rebleading it? Ive had a 1500 slave fail without leaking: all the fluid went into the void between the piston and the dust boot. Once I took it out the locating housing it all poured onto my arm when the actuating rod came out the boot...

You'll be twice as upset if you pull everything apart and you just needed a new slave. Plus whilst the engine is out you'll think you better do the rear seal, the spigot bush...slippery slope!
Roadwarrior

Hi Everyone,

As my SWMBO says; 'Your time is taken with sorting the house for the extended family' Who are moved in but a bit under our feet until I sort the house properly. So 'we' have decided to take my car to a local classic car 'lad' (probably older than a lot of you but a fair bit younger than me) that I know from years ago.

He will take out engine and sort clutch as required.

He will also replace rear of engine oil seals which have needed doing for a long time now. (black oil all over bell housing, gearbox and passenger floor).

I am providing the parts and everything is organised for the clutch.

Anyone with any ideas of what to watch for / parts lists for rear engine seal on a 1978 1500 would be helpful.

Thanks for all your help and comments. This will be the first thing I have not done myself on the car in 4 years so a bit down about it.

The fellows with overdrive in MASC Notts and Derby love them btw.

Dave
Dave Squire

I had an overdrive on an MGB, once I'd disconnected the inhibitor switch I had o/d second, which on the b box is fantastic for twisty lanes, I think the 2 to 3 ratio were miles apart, so o/d 2 was perfect, then o/d on 4 made all the difference on the motorway.

just make sure you are out of od when you need reverse or you get funny noises !

If I could o/d on a 1275 sprite than would be fantastic.

Malc
Malc Gilliver

Dave,
having someone else (provided they know what they're doing and are not a rip-off merchant) is a good thing and I'd ask him to say what's required by what he finds when looking at the work required, then addition findings as he proceeds with the work

obviously any work or parts that are impossible to do or very awkward to do with the engine in are best attended to if they need doing or look suspect

just cleaning the areas may find more work

it's all a how-long's-bit-of-string situation but penny pinching now could turn out to be a very false economy of money, time hassle and enjoyment of the car later

personally I get everything covered on the clutch system from the pedal rubber to the clutch itself sorted so that the clutch is fully sorted for many years and miles, from fluid, pipes, cylinders, etc.
Nigel Atkins

I agree completely Nigel,

Ordered complete clutch kit (cover, plate and bearing), replacement slave, replacement pipe and connector, rear engine seal, and gasket for retainer. If he finds owt else I have a spare gearbox as well. And he has a large selection of BMC bolts, washers, screws etc. :-)

Just feels odd not doing it myself.
Dave Squire

I've got someone doing some work at my home at the moment which I was going to do and there are some areas where I would have made a better job but also areas where he's done better than I would have

overall the job will be completed and that's the important bit, the work needs doing, it has been (and will be) done rather than left
Nigel Atkins

:-) The usual balancing act - Time available vs. Cash available.
Steve Clark

Just an update:

Slave and pipe changed (bearing in good condition, not changed)
Rear engine oil seal fixed.
Clutch cover and plate changed (plate was oiled up and cover marked)
Engine bay washed. :-)
Anti Freeze in.

Now for some serious testing. (If I get chance to go out that is).

Dave Squire

So, did any of that actually pin-point what was causing the original problem?
Guy Weller

Hi Guy,

The original problem was a well rusty slave that did not want to give up properly. It was still working when I took the car to Ady's. But it was 'orible' when I saw it out - I should have taken a pic but always forget!

The bearing and release arm were fine. (One of the bearing retainer screws is knackered so too difficult to remove but Ady says the bearing is fine anyway as far as he can see and it feels fine).

The slippy clutch was the rear oil seal leak that would have been best fixed when I did the bearing shells in the car last year. Its the last engine seal and gasket to be replaced since going back on the road.

Drove car home (8 miles) yesterday in the rain. No drips. No slips. Clutch near floor.
Drove car 16 miles early this morning - sometimes hitting 70 :-) - everything as yesterday :-)

He hasn't got the coolant back in the heater (I wanted the car back) so I will sort that.

It was a bit different work for Ady to big Healy's, Jags, Triumphs, Darts and MGA and B's. Character building I would say ;-)

Dave Squire

Dave,
don't forget to read and follow the instructions in the Driver's Handbook for refilling the coolant, you thought you knew last time without looking at the good book but you forgot a vital instruction

plus the good book will tell you the capacity of the heater (minus the residue left in it)

as the colder weather approaches you want your heater working fully
Nigel Atkins

No problems Nigel; I have filled it several times now as I have been refurbing the tap.
Dave Squire

yes it when you have a break from the routine that you normally - or in my case never trust my memory anyway
Nigel Atkins

This thread was discussed between 23/09/2014 and 10/10/2014

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