Clutch slave cylinder leak

[john348]

My clutch packed up and I could not see any leak so decided it must be in the slave cylinder which is hidden from view.  Tools 8mm socket, tye-wrap pair of mole grips.  My bike has had erratic feeling on the gear lever for some time. it would snick nicely into gear most of the time but ever so often would be a bit harder on initial push on the shift.  Eventually the clutch worked but became erratic to where the bite and release was but you could hold it in gear with the clutch in (until it ran out of fluid altogether).

Firstly remove the 5 screws holding the plastic cover on the RHS of the engine.  It is easy to get at as there is no fairing covering it.  The first surprise was how much thread lock there was on those screws.  I had to use a socket (8mm) all the way out.  It was a bit worrying and when they came out there were bits of thread lock that looked like thread  I am sure they are OK but I probably will run a tap down the threads to clean them up. 

With these remove the cover comes off and inside there is some black foam, cut to fit round the slave cylinder, that just pulls out.  Mine left a layer of foam attached to the crankcase and was 'eaten' away a bit.  I thought first of all it was clutch fluid but with no sign of a leak I realised it was engine oil.  (See later).  If you wanted to just bleed the slave then you can easily get at the bleed nipple with no more work.   Also there is no seal where the hydraulic pipe comes in behind the cover so there was a bit of dirt and grit collected in the bottom of the now exposed area.  There are lots of small crevasses that I used the end of the tye-wrap to clean out (very versatile tool).  I might try to seal the hole, where the pipe comes in, a bit better  when I put it all back together.

Remove the three screws holding the slave cylinder and the smaller one (shorter than the other 8) holding the p-clip retaining the hydraulic cable.  The 3 are the same length as the outer 5 but did not seem to have any thread lock and came out easily.  The slave then just lifts out.  It leaves a big hole behind it that goes straight into the engine.  It is above the oil level but be careful not to drop anything in.  I should say here I had the bike on its side stand so it was leaning away from this side of the engine.

Behind the slave cylinder is a 'paper' seal that was left on the engine it looked OK but possibly showed signs of weeping but of course this was at the bottom where any oil would drop when I removed the cylinder.

With the slave out you can twist it round to look at the piston.  The manual shows a tye-wrap round it to hold the piston in.  I actually put a socket in sideways and used that under a tye-wrap to hold the piston in.  That would be if you were going to bleed it with the slave off.  There was engine oil around so it was difficult to see if the slave was leaking but when I pushed the piston by hand small bubbles came out from the side of the piston (remember I had lost all the fluid) and there was a slight weep around the piston.  It did not matter how much I wiped it every time I pushed it got wet.  So after a lot of furious pumping I got the piston out far enough to pull it out.  That was when I found that there was a big piece of the rubber seal in behind the piston and a big lump out of the seal itself.  There were also some gold flecks in the fluid that was left but the piston does not look bad.

Looking on-line I could not find a seal kit but after measuring it looks like this slave is used on all Triumphs.  I will report back when I get the seal.  I will also report how easy it is to bleed when the nipple is a long way below the master.  I might 'blow' the fluid back I have a tool somewhere?

I did refit the empty slave housing and the cover to cover the hole in the engine.  There is already clutch fluid in it I don't want anything else in there.

I have reported it to Triumph and they have already replied but that was to get it to a dealer (I wonder how with no clutch).  These things happen so not particularly upset apart from not being able to ride the bike for a few days. (to be fair to Triumph they have replied yet again! I only reported it yesterday which was a Sunday)  They are still saying get it to a dealer where they might do a warranty job.  But that means getting it to the dealer and then risking them saying no warranty (especially as I have already taken it to bits) and then being charged dealer rates for what is a simple job.  Looking on line I see there is a dealer in Lincoln, which is where the bike started to break down?  I have just moved to the area so do not know the dealers up here?

john

[Gordon3xBBB]

I used to use Webb's of Lincoln in the mid '70s for all my Norton spares....they were very good then

[john348]

Thanks I have a Norton Commando as well so perhaps they will have some spares left???

[Gordon3xBBB]

Lucky you !
Mine was a MkV 750 Interstate, lovely bike.
Easy to ride and maintain.
Still regret selling it nearly 40 years later.
But I love my TTSE

[john348]

All fixed

got a new seal from sprint manufacturing (it comes with new spring, washers for the hydraulic hose and a new bleed nipple, just says it is for al 3 and 4 cylinder Triumphs and a lot cheaper than a new slave complete)  But I only used the seal and spring as I had not taken the rest to bits.  The seal was a lot stiffer than the one I took out but that could just be age!!!  I turned the slave cylinder over so I could put some new fluid in before pushing the piston in (same trick you do with the filter).  Just to try and get a head start.  The cylinder went in with a bit of a fiddle there is a nice taper on the cylinder to get the seal started.  pushed it in, filled the master reservoir put cloth under the master to stop drips onto the tank and body work, and decided that the tye wrap trick did not look safe so I reinstalled the slave and started to bleed.  It is difficult to keep the pipe on as there is not much room and quite a bend.  So just pumped the lever, opened the bleed (with a long piece of pipe on as best as possible and sticking up to make a sort of reservoir), shut the bleed let lever go.  AND repeat.  Pumped about 2 thirds of the master through, refilled the master and the clutch was good.  Let it settle and still OK so good enough.

Changed the oil and filter

Started her up; a bit noisy while the oil got round (should have turned it over without staring) and diffidently held the brake, left it at tick over, pulled the new clutch and put into gear?????   All was fine so did it another couple of times to check bite point (I see Formula one does that as well)  and all seems fine.

Now just to get some new rubber as these don't seem to have many marks left on them and I seem to have a nail in the back tyre????

[Gordon3xBBB]

Nice to hear Sprint Manufacturing came up Trumps..... I hadn't thought of them, which is unusual for me.....and it's all working Tickety-Boo

Well done

[Coconut]

Good to hear that you got it sorted 

Useful imformation too - for anyone eles needing to service their Clutch Slave Cylinder 

( Shame about the screw in the tyre though - I hate that ! )

Cheers 

[john348]

Means I can fit rp4 gts sooner though?  Always look on the bright side.  And of course have to get a pair.  Hopefully will still have some dry days to try them out,