Clutch Master Cylinder

[rogerguzzi]

Hello All

               We are back from the Alpine Adverture(will do a write up soon)

The clutch started to play up about 10 days in?

It was ok when cold but the pedal was jerky when hot(it was interesting on the mountain passes!!

Then just we pulled off the M20 the throttle was sticking and turned out to be a frayed cable at the throttle end (but had a spare in the boot so simple job but bloody hot?

When I removed the master cylinder the fluid was blackish and weeping out the front(new seals about 3,000 miles ago?)

So this time paid a bit more and bought a TRW one (£65 from David Manners including p&p) so not bad!

I stripped it down to clean out as I use silicon fluid and the piston assemly is different to the County one so fingers crossed it lasts better(it had been ok for probably 30,000 miles??)

photo of differences

Roger

ps we did 2150 miles on the trip

pps fueling was still a problem? will tell all later

[Nick Jones]

Yeah….. Seal/cylinder quality is variable these days & mostly lower than one would hope. 
 

Part of the problem here may be that silicone fluid is not very lubricating so your blackened fluid is probably just discoloured by fine rubber wear particles.

I’m assuming that the top one is the TRW?  Looks like the original Girling design and will accept the standard spares kit.  The bottom one crops up increasingly often (Wilwood etc) and doesn’t seem to last any better in spite of the double seal. Standard seal kits don’t fit - not sure if seal kits for them exist….

[rogerguzzi]

Hello Nick

                 The bottom one is TRW 

I would have thought silicon would lubricate it feels like that when on hands?

I might investigate people who sleeve them and I assume they use good seals?

Roger

[Nick Jones]

1 hour ago, rogerguzzi said:

The bottom one is TRW 

Oh…… well, I like the Girling style ones much better.

1 hour ago, rogerguzzi said:

would have thought silicon would lubricate it feels like that when on hands?

Agree, but….. most reconditioners will deny warranty if you use the stuff due to lack of lubricity.

[Mark]

Don't like the look of the plastic rod either, that would put me off, looks flimsy.

[JohnD]

Plastic rod?   My old modern (Citroen C5) had slave cylinder that was entirely plastic!   That failed (burst!) in the middle of a busy one way system, disabling the car, which was only eleven years old.  There's a reason for metal construction.

Edited August 1 by JohnD

[rogerguzzi]

Hello All

             My experiance with silicon is as follows.

The clutch was on silicon when purchased and I changed the clutch when I fitted an overdrive box and probably changed the seals then and 56,921 covered since then?

The brakes I overhauled just afer bought s/s pistons and new rear slaves plus new seals in Master cylinder 59,681 covered with no changes only pads and shoes

The last clutch seals lasted about 3,000 miles!!

I may have looked for NOS brakes seals at the time?

You Bu**ers have me worried about the plastic/nylon rod so I will remove it tomorrow and see if the old one will fit?

This engine has done 31,835 miles

Propshaft 44,128 miles

Roger

 

[PaulAA]

Silicon is the devil's semen.

Sorry... not sure that that helps much or adds usefully to the discussion, but the problems with TR's hydraulic systems are largely thanks to the PO "updating" to silicon and bu88ering the seals.

Empty, flush with soapy water, blow out with compressed air, flush with DOT 3 and refill with DOT 3.

Paul

[JohnD]

 Paul, flushing with soapy water seems to me to fly in the face of trouble!   Any trace of water left, and I would not be confident that a blow through with air will remove it all, will boil when the fluid gets hot, producing compressible gas bubbles  and a spongy pedal.      If you must, or better IMHO just flush in the first place, with methylated spirits.   If you have used water, the meths will dissolve the water.   What you really want is an "Azeotropic" mixture, which will reduce the boiling point of  both constituents, which methanol-water doesn't do, but it helps reduce the water content.      An ethanol-water IS azeotropic, but hands off my gin (or vodka!)!

But why recommend Dot3? So last year! (Actually 1967, but then I don't remember the '60s!) The DoT specs have got to DoT5, which is silicone based so we don't  want it, but DoT 5.1  has the same superior characteristics and is glycol based!

John

Edited August 2 by JohnD

[PaulAA]

John

You are, of course, right. DOT 5.1 it should be. And I forgot about the meths stage  But I think that soapy water is more effective at removing residual silicone than just meths, no?

A propos nothing in particular, I would relish the opportunity of an earnest conversation with the individual who named DOT 5.1 - clearly somebody of very little imagination.

[Gt64fun]

On 8/1/2024 at 8:42 AM, Nick Jones said:

Standard seal kits don’t fit - not sure if seal kits for them exist….

I tried and failed to get a seal kit for one....and I asked really nicely!

Good afternoon Ian

In response to the above, I am sorry to say that we are unable to supply replacement seals for this part

Components are used on a daily basis within our manufacturing operations and we are unable to sell them individually

Once again , many thanks for the enquiry

Regards

ZF Servicedesk

ZF Services UK Ltd

Redwither Road, Wrexham Industrial Estate, LL13 9RD, Wrexham, United Kingdom

Tel +44 333 240 1123

meinir.jones@zf.com

aftermarket.zf.com

[Nick Jones]

The cynical might conclude that the design was intentionally changed so that they cannot be rebuilt…..

No doubt for “safety” reasons.

Agree with you on the 5.0/5.1 thing Paul. It’s astonishingly stupid!

[rogerguzzi]

Hello All

             I removed the clutch master cylinder and fitted the metal one.

Then this numpty found some more seals along with an old cylinder so I have rebuilt the county one as a spare.

So after what has been said about the TRW one I think it is the same as the TR7 one?

I think think the one seal is the same as all the earlier ones its just the extra one that is different and probably as Girling did??

Rob Sport shows these and anther supplier and I think I bought a set with the extra  one?

Triumph TR7 TR8 ** CLUTCH MASTER CYLINDER REPAIR KIT ** | eBay

HERALD GT6 SPITFIRE TR7 CLUTCH / BRAKE MASTER CYLINDER REPAIR KIT SP1963 GRK1029 | eBay

Roger

ps not removing it again and sticking to Silicon as it has been ok for me and no worries about paint damage!

[thebrookster]

3 hours ago, PaulAA said:

But I think that soapy water is more effective at removing residual silicone than just meths, no?

I'm inclined to agree with you there Paul, although from a tangential bit of evidence! My turntable (Townsend Rock 2) uses a damping trough that is filled with silicon, and the old Fairy washing-up liquid is about the only thing that reliably cleans up spills.

[rogerguzzi]

Hello All

                yet another supplier?

I just assume later Girlings were all the same with the exra seal

So feel a bit happier now and have ordered a set of seals from Robsport(belt and braces??)

Roger

Master Cylinder Repair Kit - GRK1029 | Rimmer Bros

[rogerguzzi]

Hello All

              Well its not the Clutch Master cylinder????

I took Spitty for a spin and to refuel today and all seemed ok but she got hot the clutch started to be jerky/sticking on releasing it(Rowlocks Rowlocks)

The strange thing is with the engine off it is smooth but with the engine running but out of gear it is jerky/sticking!!!

I fitted a new pressure plate when the gearbox was out just before the Spanish trip and I reckon it had done about 3,000 miles before it started to play up(Moderen CRAP?? in a Borg and Beck box??)

The old one had done about 50,000miles but was NOS(Proper Stuff!!) 

I only changed it because the fingers had a lot of wear on them(wish I had not now as it means bloody greabox out AGAIN!!)

It will have to wait until the winter now and hope it last's and will look for a NOS at stoneleigh if there is a show?

Pi**ed off Roger

[Mark]

A real pain in the a**. Could there be any contamination, oil from rear seal? Probably as you say, just shite repro parts. 

[Nick Jones]

15 hours ago, rogerguzzi said:

The strange thing is with the engine off it is smooth but with the engine running but out of gear it is jerky/sticking!!!

Eh?! Wat? The pedal action is?

[rogerguzzi]

4 hours ago, Nick Jones said:

Eh?! Wat? The pedal action is?

Hello Nick

                Yes the pedal action?

Tested it this morning on a cold engine and is smooth with engine off and on???(did not bother to get it out to try in the gears as it will not have changed!

Out with all the Wednesday group tomorrow so will be a good test or nightmare?

Roger

[Nick Jones]

Slave cylinder? Pivot pin for the arm making a bid for freedom? Check those before pulling the box. Otherwise I reckon it’s the release bearing carrier getting hung on the guide tube up rather than the actual clutch. Can’t thing of any other reason why it would be temperature or engine on/off related.

[rogerguzzi]

Hello Nick

               It will not be the pin as I modified it years ago to a headed pin and bushes and grub screwed arm to pin,

I had it al out when doing gearbox repair but can not remeber if I lubricated the guide tube to carrier!

I may change the slave cylinder seals again first.

I wonder if I could lubricate the tube while its out? With long spout on the oil can and just a drop of oil

Roger

[Nick Jones]

15 minutes ago, rogerguzzi said:

I wonder if I could lubricate the tube while its out? With long spout on the oil can and just a drop of oil

Got to be worth a go. Or maybe a little moly grease on a long brush?

[rogerguzzi]

Hello All

             I have cut a bigger hole in the tunnel to save removing it!!

The slave cylinder was tending to stick as I pushed it in and let it go slowly then when stripped I could see black marks in the bore that washed off with thinners(rubber from seal?)

There was a bit of a scuff mark in the bore but I have polished it out with some 2000 grade wet and dry with 3 in 1 oil(nice and smoth now)

I have also remached the grove that the front seal sits in as I could not remove the cylinder by just taking out the clamping bolt and pulling backwards (suspect either the rubber is wrong or groove not deep enough?(ok now)

The blacking on the piston is a bit worn away I was thinking of making a new one in Stainless Steel and a touch loger so the pedal movement will not be hard on the floor? (Or what about bronze?? perhaps not Aluminium?)

I thought I had some seals but I must have forgot to replace them!!!(ordered now and should here tomorrow paid the couple of pound extra for next day and post says by 13.00 tomorrow?

Roger

ps the clutch arm moves very easy so hoping it is just the slave cylinder?

pps will try and put a bit of lube on the bearing sleeve!

pps why do we bother with these bloody old cars now we can not get good spares anymore???

[rogerguzzi]

Hello All

              I think I will make one in bronze and as I said a touch longer to make pedal not on the floor ??

Pl;us if it wears I am sure it will take a long time?

It's just the seals that are the problem!!!!!!3

Roger

[rogerguzzi]

Hello Learned Classic car Mechanics

                                                             Well things are touch better(Just)

We went out last wednesday and all was fine until on the way home(about 30 to go out of 165miles!)

It was baulking into and our of gears?

So on checking there was touch of air in the remote bleed pipe! so re bled and still a bit iffy?

We have been out today (145miles) and most of the time it is ok ish just baulks now and then?

Now the odd thing is the pedal action is nice and smooth with the engine off but a bit jerky on releasing with the engine running??(even out of gear?)

So now I am thinking it is not the gearbox circlip but the Bloody Repro clutch pressure plate as when I changed the slave cylinder seals the clutch arm moved nice and easy and I gave it touch of oil for luck?

So If it stays the same I will just drive for the rest of the season and remove the gearbox in the winter and look for a NOS pressure plate(this Numpty threw the old one in the bin instead of sending to the people who rebuild them to see if it could be reconditioned!!!!!!)

Roger

ps I am going to get my finger out and crack on with the Vitesse as I have rebuilt the o/d gearbox and fitted a rebuilt 3.63 diff(by me?) and converted it to swing spring and upgrade head studs etc and have Megajolt half fitted(toothed wheel and sensor and coil pack and leads) plus the power steering and Nippon Denso Alternator!!