MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - Best quality clutch kit?

I modified my car to fit a 1275 clutch (and roller release bearing), which I thought might outlast me. But it is slipping after 16,000 miles. What suppliers/brands do you guys recommend? Is it really worth paying £200 for a Borg and Beck one? Is a Girling one at £87 any good?
Les Rose

Les
Being modified is it possible that the pushrod in the slave cylinder is too long and has bottomed out (no freeplay) causing the clutch to slip-?
William Revit

Yep sounds like Willy's right.

16000 miles to wear out a clutch raises suspicions about there not being free play.

When I bought my Capri, the seller said the clutch slipped and was knackered.

When I got it home, and got under it, I found the adjustable pushrod was simply too long. Backed it off and no more slip. But the damage was done, it was nearly at the rivets and the flywheel had suffered damage heat too.

The friction material is likely identical, girling or borg beck. So I would just buy the cheapest, AFTER resolving the cause of the premature wear.


anamnesis

Some roller release bearings require the pressure pad to be removed from the diaphragm in order that they can press directly upon that diaphragm.
Some are heavy and droop: better employed on a type 9 Sierra gearbox conversion where they are supported by a guide tube over the first motion shaft.

Failure to remove the pressure pad, if required, with throw all the relevant measurements out.

If using a stock 1275 clutch with a pressure pad on the diaphragm then my release bearing is the one to use as
No modifications are necessary.
Weight under 250gm
Can self centre and, to a degree, can run off centre.
A direct replacement for the carbon release.
Fit & forget.

Tenth anniversary of making them.

Have you examined the clutch for evidence as to why it may have failed?
Alan Anstead

Willy, very recently (about 300 miles ago) I had to service the slave cylinder and fitted a new pushrod. I checked it against the old one and it was identical, except of course for the wear. I did wonder about whether this increased the effective length. Years ago, before fitting the 1275 clutch, I made an adjustable pushrod, but after the conversion I found it worked best at exactly the same length as a standard non-adjustable one, so went with that.

Alan, the roller bearing has been in the car for 10 years and has not given the slightest trouble up to now. Of course I haven't examined the clutch yet as it's still in the car. Maybe the first action is to try shortening the pushrod.

Les Rose

Just check that the pushrod hasn’t bottomed out by seeing whether you can push it back into the slave.
Dave O'Neill 2

Agree with Dave, - just check if there's any free movement with the slave/arm--no use changing to a shorter pushrod if you already have free travel there.
William Revit

The pushrod has about 2mm of free movement. Another cause of rapid clutch wear occurs to me. I have a 270 degree camshaft which gives little torque below 2000 rpm, especially in a 998 engine. The ribcase gearbox has a much higher 2nd gear than the original, as we all know. I read somewhere that this encourages the driver to slip the clutch instead of dropping into 1st, which requires double declutching of course. I might have been doing this subconsciously.
Les Rose

Out she comes then eh. looks like your original diagnosis of a worn out clutch plate could well be correct.
On the pushrod length question- if you still have 2mm clearance with a worn out clutch ,then the pushrod length you have is spot on--no need to change that.
William Revit

Check John Twist's YouTube video regarding carbon vs roller release bearings.
Glenn Mallory

Have you got a link Glenn?

Can you summarise what he says?

Roller vs carbon, roller is way better, as long as it's the right design for our setup.


If it's this one, "282 MG Tech MGA Roller Release Bearing", he says at the beginning that roller bearings don't and can't work on MGs.

https://youtu.be/4KIdkOWVcGg?si=eZd77pa-sfhKqGL7

Well he dead wrong there. Odd that he was so adamant. Because I and Alan in particular with the many he's made and sold, have proved beyond any doubt, the right design rollers are better, and outlast carbon releases on Spridget clutches.



anamnesis

Glenn
‘The proof is in the pudding’ with roller release bearings. Next month (March) will be rhe tenth anniversary of my producing them in various forms.
Roller release bearings do work on Sprites & midgets

When I started making them people would post John Twists video hanging on his every word like religious zealots: fortunately that trend died out.
But some still hang on as some still claim the earth to be flat.
Roller release bearings do work, some better than others, giving reliability and longevity.






Alan Anstead

I have at last fitted the new driven plate. While I was at it I fitted a remote bleed kit from Peter May, but it leaked so I am back to grovelling in the footwell. But the insoluble problem so far is that the clutch will not disengage, despite repeated bleeding. I have 1-2mm clearance at the slave pushrod end, and I have not changed anything else. Yes I did check that I had installed the plate the right way round. I don't think lengthening the pushrod is the right thing to do, but what do you think? BTW the old clutch plate was worn but not dramatically.
Les Rose

A whole day has been wasted today getting nowhere. Let me recap my setup.

948 flywheel drilled to accept 1275 clutch.

1275 slave, new seals fitted a few weeks ago. Not leaking now.

master cylinder sleeved down to 3/4" with brass tubes, to suit both clutch and disc brakes.

Roller release bearing.

I have had no problems with this clutch in 11 years, apart from normal wear. But what is happening now is baffling. Although there appeared to be adequate free movement of the slave pushrod, after a few operations of the pedal this disappeared. I tried experimenting with an old pushrod that I had made adjustable. If I made it shorter would I get some free movement? Well yes initially, but again it disappears after a few pedal presses. Logically this isn't the way to go, as a shorter pushrod allows the slave cylinder to fill with more fluid and there is less movement not more.

So should I bleed fluid out of the slave? Is there something wrong with the master? I thought I understood these hydraulic system, but obviously I don't.
Les Rose

Les I sympathise and understand your agony.

However, in the light of what you said in your most recent post, what are the seals in your master cylinder like?

Replacing the seals on my not very old master cylinder helped for a while but not for long. Replacing the whole cylinder almost completely cured the dragging so that it would go into 1st and reverse with only a slight rattle. A new spigot bearing that had been stored in oil for around 3 years just completed the job so that it goes into 1st and reverse perfectly almost every time.

I have the feeling that modern cylinders are now considered as consumables.

Colin
C Mee

Thanks Colin, £200 seems a lot for a consumable item. I am considering a new one, hence I know the price, but they are just bare steel and rust internally. Brake fluid is hygroscopic. This is one reason for the brass sleeving. It's a lot of work to get the master out, with the risk that new seals won't be a permanent fix.

What I have is a lot worse than dragging, it's not even trying to disengage.

On a related matter, what with all the leaks I'm having, what paint really resists brake fluid?
Les Rose

Les,

it may be easier to covert to synthetic fluid (for your clutch) than find paint which is resistant to brake fluid.
Synthetic isn't hydroscopic so in theory your cylinders shouldn't corrode internally.
Jeremy MkIII

Les, you say you had some free movement to start with which dissapppeared after a few pumps which suggests to me that all the fluid is not returning to the master cylinder and therefore you get an increased amount of fluid with each push of the pedal.

Trev
T Mason

Two theories on synthetic brake/clutch fluid-

Yes normal fluid is hydroscopic but if changed regularly that's an advantage. The fluid absorbs the moisture up to a point and is removed with a fluid change

On the other hand synthetic fluid doesn't absorb moisture so any moisture gathers in the system, usually in the cylinders and is free to rust away at will
William Revit

Willy
So, if using synthetic, as I do, it's worth draining a bit of fluid from the bleed nipples now and then? That's still easier than draining the whole system.
Bill B

Yes Trev, that seems to be what is happening, which points me to the master.
Les Rose

With synthetic fluid, surely the water 'drops out' and sits in low points. Getting it all out must still full drain I'd have thought.


anamnesis

This is an extract from the Automec site:

DOT 5 Silicone Brake Fluid repels moisture so, unlike standard polyglycol brake fluid, it never needs changing.

Rust and corrosion are inhibited as moisture is kept out of the system and the high boiling point of 260 degrees C is maintained throughout the life of the product therefore ensuring consistent, safe performance.

Does not damage your paintwork if spilled.
Will not easily catch fire in the event of an accident.

Used exclusively by the US military in their light vehicles.

DOT 5 Silicone Brake Fluid will essentially eliminate brake system wear and corrosion for at least 70,000 miles with service periods in excess of 100,000 miles being feasible.

Jeremy MkIII

I use Dot 5 in all of my cars. I have used it in my daily driver, a 1990 Ford Escort XR3i, for probably 30 yrs (just short of 250,000mile) , my Frogeye probably about the same and my Sebring Rep 22 years.
There are those that say it is not compatible with rubbers, not compatible with Servos &c. My experience is all good.
The fluid on the Ford has just been changed but only because all the original steel brake lines have been changed. One rear brake cylinder has had to be replaced but still on original Servo &c.



Alan Anstead

Mine's a mere 18 years Alan; so a while to go yet.
Jeremy MkIII

But can anyone answer the title question regarding “best quality”?
Philip Sellen

You can't have "best" quality.

Something is either quality (meets your requirements) or it is not.
Tim C

We have moved on from clutch quality Philip. There has been a bit of mission creep with this thread. The clutch is installed, I'm now trying to get it to work. Meanwhile I'm tarting up the master cylinder and pedal box area. Always good to have somebody remind us of the core issues!
Les Rose

Can somebody tell me please the correct length of the slave pushrod? This is a 1275 clutch and slave.
Les Rose

After clutch slipping episodes on a V8 B, when I removed it, the pressure plate wasn't flat and only half of it showed any sign of having made contact with friction material. It came from a well known supplier too. I replaced it with a Borg & Beck item, which, I checked, was perfectly flat and now transmits 300ft/lbs, without issue.
Motto......... Double check everything you buy!!
Allan Reeling

Good advice Allan, but I haven't replaced the pressure plate which has always worked perfectly. The new driven plate is identical to the old one, albeit not worn.

I didn't get a reply re slave pushrod length, but Google AI says it is 2 11/16" measured from the eye centre. That is much longer than the one on the car, which is 2 3/8" (and worked perfectly). I think I have fully bled the clutch system, but I am still not getting enough travel so it won't disengage. Should I use the longer pushrod? To fit this the slave piston has to be forced back, pushing fluid back into the master, but the internal spring keeps the release bearing in contact with the release pad. Before all this shenanigan I had about 1mm free movement of the release lever, which I was advised was correct. The official workshop manual is totally silent on all this.

We discussed this on the clutch dragging topic, where I thought I knew what I was doing! Not so sure now.
Les Rose

Les,

It may have been asked before but how much pushrod travel do you have at the MC before the fluid port is closed off?
David Billington

Dave, how would I measure that without dismantling the MC?

I forgot to mention earlier that I had to replace the MC seals again because they seized in the bore. I honed the bore again with 600 grit. I am no longer sure that the clutch system is properly bled, so I have bought a pressure bleeder. This time I am doing it from beneath the car, with the slave removed from the gearbox and the piston clamped. This way I can get the bleed nipple uppermost.
Les Rose

I am now pretty sure that the clutch is bled. But it still won't disengage. In desperation I have ordered a new MC.
Les Rose

I have just measured two slave pushrods that I have in the garage and they are both 2-11/16”. I can’t guarantee what they came from, but they’re more than likely to be 1275s, as I haven’t had much else.
Dave O'Neill 2

Les, have you measured how much stroke there is at the slave? It is the most relevant measurement if a clutch is dragging. Too low = hydraulic problem, correct = clutch problem such as popped linings. And on these clutches too much stroke can mean that the release pad has contacted the plate and is pushing it onto the flywheel, causing drag that way. The latter is unusual but I have encountered it a few times when the wrong size slave and/or master is used.
Paul Walbran

Please excuse slow replied Paul, there was a short delay why I installed a new master cylinder. Sadly the clutch behaves exactly the same. I have made the pushrod adjustable and with it set at 2 11/16" there is no free play and the release bearing seems to be tight up against the release pad. At this setting I only have 5mm of pushrod movement. This is after bleeding the system again using the pressure bleeder, and with the slave detached, the bleed nipple uppermost, and the piston fully retracted and held in place with wire. If I adjust the pushrod to get about 2mm of free play there is 9mm of pushrod travel, and still no disengagement.

With the roller release bearing I have always used a shorter pushrod and never had any trouble with it. The pedal does feel as if there is air in the system but I really don't know what more I can do to get it out.
Les Rose

I have started a new thread called "Clutch won't disengage".
Les Rose

This thread was discussed between 11/02/2026 and 14/04/2026

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.