The Triumph Dolomite Club - Discussion Forum

Thanks for the advice Jon. All things considered I've decided to go for a new one, but thanks for the offer. Measured the existing one's bore as best I can and it appears to be 7/8" diameter. It is a Lockheed, for what it is worth so going for the TKC2786.

I'll order a set of seals for the m/c while I'm at it, just in case.

Thanks again Jon.
Tim

Ictoan wrote:If a m/c or slave were at fault would they always leak?

Tim, sorry to pick up on this a little late.....
a faulty slave will invariably be leaking but a master cylinder may not always be so.

Based on my experience, I think you will need a MC as well as the slave.




Ian.

sprint95m wrote:

Ictoan wrote:If a m/c or slave were at fault would they always leak?

Tim, sorry to pick up on this a little late.....
a faulty slave will invariably be leaking but a master cylinder may not always be so.

Based on my experience, I think you will need a MC as well as the slave.

Ian.

Hi Ian,

Thanks for the above and it is something that had crossed my mind. I have ordered a set of seals for the m/c as well as a new slave. Belt and braces.

I did try to clamp the hose and press the pedal and there did seem to be more pressure, but by the time I got round to trying this there may have been a bit of air got in so it wasn't a very scientific test. I had but a piece of polythene under the reservoir cap to try and stop fluid leaking.

I did ask a mechanic to have a look at the slave and he did think it didn't look too bad but I have decided to replace it anyway. I don't know if some water had got in but it was very mucky behind the outer rubber and the pushrod is quite rusty.

Time will tell if this cures it.

Cheers,
Tim

Well, replaced the slave cylinder but that does not appear to have fixed things. Next up is to replace the seals in the master cylinder. Just need to remove the cylinder and I'm into it, right?

No!! I have removed the two nuts and washers, disconnected the clevis pin from the pushrod, disconnected the reservoir pipe and as the pipe to the slave cylinder seemed very reluctant to move I have taken Jon's advice and left it connected and pulled the pipe up past the bellhousing for easy removal....but I cannot shake the master cylinder off the two bolts, it seems to be stuck fast to the bulkhead. I have tried to drift it out with a piece of wood and a hammer but to no effect.

Any suggestions? I don't believe the master cylinder is threaded where the two bolts come through the bulkhead, and besides they look as if the heads are welded in place?

Thanks, as always,
Tim

Panic over, but boy was that stuck fast. Think it must have been there for 39 years.

Relieved,
Tim

OK, next problem, and possibly a game stopper.

Got the piston etc out of the bore and while trying to understand what the 'spring thimble' is that needs to be straightened I noticed that the end of the spring is broken off.



Should I just cut my losses and order a new master cylinder or or can anyone tell me where I might easily obtain a spring?

Are these springs known to break?

Oh, and what is the spring thimble?

Thanks,
Tim

The spring thimble is the metal cup that the spring sits over.

The broken spring will have scored the inside of the cylinder creating a passage for the fluid that the seal cannot close. It can be resleeved, the brake ones we recondition are sleeved in stainless steel as a matter of course. OE seal kits had a replacement spring in them, but most aftermarket ones don't.

We don't yet recondition clutch MCs as new ones are still available at a lesser cost.

Thanks Alun.

I did eventually work out the thimble.

Clutch - Master Cylinder Stainless Sleeved £65.99# Are these 'new' or re-conditioned and do you know if the club has them in stock?

Thanks,
Tim

I would look at the bore before writing it off....

Sprint masters with the remote reservoir are getting quite rare.

You can pinch the spring and entire piston from a master with the normal integral reservoir. You can even use one
but it makes it a bit hard to fill with the Sprint air box etc....but it will work just the same.


Jonners

I have had a closer look at the bore and I have to say it does look quite badly marked, in my eyes. I have tried to take a picture.



Still not 100% clean at the very bottom but there appears to be marks further in from the outlet hole.

Tim

That doesnt look good I agree....
Does it come off with 1200 grit wet and dry in brake fluid? If not its a resleeve...or a new one.

The trouble is some "new" ones have metric threads, so be careful when buying.

Jonners

Hi Jon. I haven't tried any 1200 wet and dry, I don't think I have any to hand, but I think I would prefer to get a new m/c. Knowing my luck I would make a hash of it I am aware of the kit car girling 'style' m/cs and the difference in the threads but assume the club ones are the correct thread. I also realise that the ends could be changed or adaptors used but by the time I do that I might as well get the correct one in the first place. Hopefully the club has them in stock.

I'm a 'slow' mechanic, in other words it takes me an age to get anything done while I hum and hah, and I dont have the benefit of a fully kitted out workshop. The car is actually sitting on axle stands on the drive, and has been for a fortnight while I prevaricate over the best course of action, waited for parts and dodged the showers. Over the years I've done all sorts of jobs on cars so I'm not a total novice, but I would never profess to be an expert, however my Dolomite knowledge is expanding all the time thanks to the good folk on this forum, for which I am grateful.

Cheers,
Tim

Jon Tilson wrote:Sprint masters with the remote reservoir are getting quite rare.

Yes and no.
Replacements are readily available through the kit car suppliers.....but these are sold in modular form
so for a Sprint clutch you would need the MC, a clevis fork and a 3/8" to 7/16" adapter.


For example
http://www.carbuildersolutions.com/uk/0 ... -reservoir




Ian.

...unfortunately not available through the club at present

xvivalve wrote:
We don't yet recondition clutch MCs as new ones are still available at a lesser cost.

Historically some were done, but going back a few years when options seemed few and that is what is still quoted in the magazine. However, options now abound and places like Parts4Triumph/David Manners can supply the correct items as highlighted by Ian's example, but you have to be specific with the sales staff to make sure you get the correct bore and thread sizes as there are many variants.

If we did start sourcing reconditioned stock you could add about £20 to the cost stated in the magazine based on what brake cylinders cost to get done.