The Triumph Dolomite Club - Discussion Forum

Hey everyone

I’m back with another issue with something I bought from Rimmers and I just want to check that it’s not an issue with my part.

Basically, clutch slave cylinder broke on my brothers 1500, so bought a repair kit instead of a new cylinder. Kit came, took the cylinder apart and the inner seal was completely different. The inner diameter of the seal was so much smaller than the piston and I couldn’t get the seal in the cylinder while it was on the piston. I could get it into the top part but not into the actual bore.

My question is, is it meant to be that tight? It was wedge shaped and I could get it in with the wedge pointing into the cylinder but not when pointing out which I assume is the correct way as the old one pointed out

Many thanks

There are at least two piston types in the 1500 slave, sounds as if you might have the wrong seal kit for the piston. It should be tight, but lub'ed with a bit of clutch fluid it should slip home fairly easily.

The Club do have a small number of 1500 slaves which have been sleeved with stainless steel and fully refurbed, but they're a bit more expensive than a seal kit.

Over the years I have found that various slave cylinders have been fitted to 1500cc dolomites. The majority have had a 5/8 diameter bore but I have also come across 0.7 inch and even a couple of 3/4 inch slave cylinders.

The problem which causes the new slave cylinders to fail has been identified and covered in detail in Dolly Mixture. You need to measure bore or piston diameter and check you have the correct seals for that. If the piston is not an original girling design the seal will not last long.

The Girling is on the RHS.

Richard the old one wrote: ↑Wed Nov 24, 2021 9:43 pm Over the years I have found that various slave cylinders have been fitted to 1500cc dolomites. The majority have had a 5/8 diameter bore but I have also come across 0.7 inch and even a couple of 3/4 inch slave cylinders.

The problem which causes the new slave cylinders to fail has been identified and covered in detail in Dolly Mixture. You need to measure bore or piston diameter and check you have the correct seals for that. If the piston is not an original girling design the seal will not last long.

The Girling is on the RHS.

Yes, the one I have the one in the left, and the seal kit appears to be for the one on the right. Guess I’ll just have to shell out for the full cylinder.

It was getting late last night when I responded so in error the bore sizes relate to the master cylinders but the photographs do relate to slave cylinders.

I believe that the clutch hydraulics is the system that over recent years has given OHV owners the most problems. The majority of the problems have been slave cylinders, part number GSY105, leaking. Triumph Dolomite Club members were advised in Dolly Mixtures that the cause of this problem had been identified as being a poor design of the operating piston and its associated seal used in the new replacement cylinders. The indication is that only one company was producing these replacement slave cylinders and was providing them to all the regular Dolomite parts suppliers. A number of the suppliers were contacted but only DMG (David Manners) undertook a detailed investigation and provided a response to the TDC. This was included in edition 205 of Dolly Mixture and within the statement the company advised that a number of the cylinders had been modified and the part is available for supply. Due to the limited numbers they have, they are being sold with an old unit surcharge in order to collect core units that can then be reconditioned to maintain supply. Once the stocks of these new units are depleted the part will be superseded to GSY105E, to indicate that it is a reconditioned unit from old core. My concern and suspicion is that will be a number of unmodified new slave cylinders held by other suppliers which will be sold to OHV owners.

I telephoned DMG today on tel 01215444040 and was advised that they do have some stock of modified new slave cylinders @ £40 plus VAT plus P & P and that the surcharge is £30.

If you have any spare old slave cylinders please do not throw them away as the club may need to recondition them at some point in the future currently the club does have some reconditioned units but I do not know the price.

The Club stock currently consists just three units and they have been sleeved in stainless steel as part of the reconditioning process. They are £85.00 each inc postage to UK addresses on an exchange basis.

DMG could not tell me what the price will be when they start reconditioning old units but I would expect the price to increase significantly as they will need to be re-sleeved and most likely have new operating pistons manufactured along with a new girling type seal being fitted. My assumption is that the current modification will consist of just replacing the operating piston and its associated seal.