Clutch Pedal Travel

[Ty_bach]

The clutch on my Herald 1200 does not fully bite until the pedal is nearly at the top of its travel. Does it mean that the clutch plate is nearly worn out?

I have checked the pedal free movement and linkages as per the workshop manual and all appears ok.
Cheers

[RobPearce]

It might indicate the driven plate is nearing the end of its life. On the other hand, my GT6 has been exhibiting that symptom for five years, including a Round Britain Run...

[glang]

Its almost certainly wear on the friction plate but is it something thats got worse over a long time, short time or is the car new to you?

[Ty_bach]

Many thanks for your interest.

I have owned the car since 1986 and it was previously owned by my wife's grandfather who bought it new in 1966. After his demise, and between 1986 & 1989, I stripped the car down to the chassis and rebuilt it. At that time, I replaced the clutch plate and thrust bearing only. Since then the vehicle has 'only' done about 25,000 miles. The hydraulics are still '1966' factory fit except for the copper clutch fluid pipe fitted at the rebuild. DOT4 synthentic fluid used.

So, am I right in thinking that (a) the clutch cover/pressure plate may be worn/tired/weakened? (b) the friction plate may be worn down - after 25,000 gentle miles? (c) the master and slave cylinders are past their best?

I think I have noticed the excessive pedal travel in the last six months. I did a 1500 mile trip to southern France in May (car had never been abroad before) but no heavy mountaineering or excessive strain on the clutch from the usual use.

Martin

[Mark Hammond]

New clutch'll sort it out.  Replace the disc, cover and release bearing as policy.  Try to find NOS Borg & Beck or at worst QH and not the cheapest that is out there or you'll be doing it again in 6 months.

M.

[Ty_bach]

Thanks Mark.

Should I replace the pressure plate at the same time? if so, Should I go for a diaphram clutch plate or stick with the coil spring type? I am sure I used a QH friction plate last time, so I will look out for a B&B this time.

As i am planning more tours of Europe, including possibly the Alps, I think it would be best to replace the master & slave cylinders too. As these parts are 49 years old, I guess they might be getting a little tired.

Martin

[Mark Hammond]

That is what I just said, replace ALL 3 components the pressure plate is the cover.  Coil Spring type is fine but if converting to diaphragm type you'll need to change the flywheel and the slave cylinder to match as these differ according to which clutch is used.  Incidentally another reason why the pedal is high is if you had the slave cylinder from a diaphragm type clutch fitted.

M.

[Ty_bach]

Sorry! I should have re-read your last message before pressing send! Many thanks for your input.

Martin

[Bitumen Boy]

As for the hydraulics, yes, I'd suggest some work would be in order in the interests of reliability. Master cylinders contain several small parts to do with the valve seal that do wear eventually, and if it's the original then I would suggest replacement. Not a cheapy one, I've heard they're not very good, but I recently stripped and inspected (before fitting  ) one of the "original type", TRW ones which compared well to the original Girling. Slave cylinders, however, are much simpler animals, and so long as there's no obvious wear to the bore or piston and the spring doesn't seem excessively weak, it should be fine with a clean up and some new seals.

[Ty_bach]

This is what I have been thinking, I will dismantle the slave cylinder to see if its worth using a repair kit or not.

I've seen on fleabay Borg & Beck kits HK6943 which state (or suggest) they are suitable for my 1966 Herald 1200. It was suggested in an earlier post that to fit a diaphram pressure plate, i would need to change the flywheel - presumably for a 13/60 one? I don't particularly want to go to the lengths of swapping flywheels. Question is, will a HK6943 be a straight forward alternative, or not?

Whilst the prop shaft is removed, I plan to grease the Hardy Spicer joints and replace the leaking diff input shaft oil seal.

[heraldcoupe]

If your clutch was releasing at the bottom of it's travel then a hydraulic issue would be quite likely. A high biting point is very unlikely to be a hydraulic issue though, it suggests wear to the friction surfaces of the clutch.
Not that I'm suggesting you should leave the hydraulics alone, pre-emptive re-sealing is a good idea while things are apart, I don't think they're contributing to the current problem though,

Cheers,
Bill.

[herald948]

Quoted from Ty_bach

I've seen on fleabay Borg & Beck kits HK6943 which state (or suggest) they are suitable for my 1966 Herald 1200. It was suggested in an earlier post that to fit a diaphram pressure plate, i would need to change the flywheel - presumably for a 13/60 one? I don't particularly want to go to the lengths of swapping flywheels. Question is, will a HK6943 be a straight forward alternative, or not?

A quick Google search on that part number seems to indicate that the HK6943 kit IS the 6.5" diaphragm clutch kit, so it's fine if you do want to change your flywheel, slave cylinder and throwout bearing carrier.

[Clive]

And to be fair, swapping a flywheel is a 10 minute job. It is getting to it that is the hassle, but doing a clutch you are in anyway.

[glang]

Quoted from Ty_bach

Many thanks for your interest.

I have owned the car since 1986 and it was previously owned by my wife's grandfather who bought it new in 1966. After his demise, and between 1986 & 1989, I stripped the car down to the chassis and rebuilt it. At that time, I replaced the clutch plate and thrust bearing only. Since then the vehicle has 'only' done about 25,000 miles. The hydraulics are still '1966' factory fit except for the copper clutch fluid pipe fitted at the rebuild. DOT4 synthentic fluid used.

So, am I right in thinking that (a) the clutch cover/pressure plate may be worn/tired/weakened? (b) the friction plate may be worn down - after 25,000 gentle miles? (c) the master and slave cylinders are past their best?

I think I have noticed the excessive pedal travel in the last six months. I did a 1500 mile trip to southern France in May (car had never been abroad before) but no heavy mountaineering or excessive strain on the clutch from the usual use.

Martin

It certainly seems strange that the friction plate has worn so quickly but I cant think of any other simple explanation so maybe there was a problem with the pressure plate (dont know how many miles that has done) which has finished it off early.... However as it sounds like you're going to renovate the hydraulics anyway I would do that first and see if there's any improvment before rushing in to change the clutch itself.

[Ty_bach]

When I rebuilt the car between 1986-1989, I had a young family and had to save money before buying the next lot of spares. Consequently, 'if it ain't broke don't fix it' attitude tended to prevail. So, the clutch friction plate and thrust bearing were probably the cheaper/cheapest I could get and the master & slave cylinders are untouched since 1966 - as far as I am aware. The pressure plate is probably 1966 too.

Now I am very fortunate to have a few more pennies in the bank and my sons are no longer on my payroll, I can afford to do the job properly using better materials.

[Paudman]

If it's a coil-spring beware of 'NOS' versions with only 6 springs; ok maybe for 948s but not for the 1200 or larger engines which need the 9 spring covers. You can also replace the springs themselves without replacing the entire cover, provided you can find the springs...

[ferny]

My clutch was worn so I fitted a NoS B&B. It lasted two years (20-30k miles) and then the old LuK clutch was put back in which lasted a lot longer than its new replacement - including being fitted to a 1500 engine. Sometimes you have to weigh up the pros and cons of using a 60 year component and a new one made in a different (inferior?)  way.