The 'E' Type Forum

Just returned (to Kent) from a Backwater Tour to the Highlands - approx. 1500 miles in a week - great fun. Having filled up with petrol for the 450 mile trip home - no clutch, foot to the floor. Ah you think, slave cylinder. No, you then think, a new one was fitted only a month ago, bought from one of the usual suppliers. Breakdown cover (through Peter James) is with the AA, man arrives, crawls underneath and confirms it's the slave cylinder. In my box of spares, no slave cylinder because a new one has been fitted so that won't fail, will it? Now the interesting part - the AA man phoned the AA's suppliers, Unipart, who could not help with a new slave. So he rings another garage, and then another. Eventually he phones a friend the other side of Glasgow who has a garage and who happens to have just bought a new slave for a Jaguar he is doing up and he says I can have it. AA man disappears for an hour or so and returns with a new slave which is a Lockheed. Slides under the car and after some grunting and groaning, we bleed the system and, lo, a working clutch! Four hours from phoning to being back on the road (and he even dropped me and my wife off at a nearby hotel so we could get some lunch). Above and beyond the call of duty in my opinion and a thoroughly nice chap. AA (and probably RAC) seem to employ mechanics rather than tow truck drivers - worth considering next time your breakdown cover/insurance comes up for renewal.

And on replacement parts, recently fitted new halogens and bowls - again from a recognised supplier. After a couple of days, fuse blew when using flash and dip. After nearly three hours of investigation (with Angus) turns out to be a short as the back of the bulb holder was rubbing on the bowl - poorly manufactured. Once insulated, no problems.

And further on replacement parts, bought new TEX wiper arms and rubbers - two of them fell off five times between them on the trip - the clip is simply not strong enough to counteract the spring on the arms. Had one of the old ones as a spare and it's still on! Old blades are also better than the new ones.

So there you have it - old slave made by TRW, no good (aren't they Lucas?), Tex wiper arms, no good, AA man brilliant!

Well done by the AA man because that slave can be a bugger to remove!

The reproduction clutch slaves are a real problem and after having three fail in quick succession (car was still over the pit!) I went hunting on eBay for a NOS AP Lockheed unit. Has been working fine ever since. I think the problem is the rubber seals are made in China and I am told, maybe apocryphally, that although the dimensions were sent over in imperial they were converted by the manufacturer to metric because all their tools are that way. Rounding errors crept in and you only need a few thou out for it to cause problems. My advice has since been:

1. Buy NOS Lockheed slaves when they appear on eBay - currently: http://tinyurl.com/p3ozxzx
2. Buy a repro slave but rebuild it immediately with a genuine Lockheed seal overhaul kit: http://tinyurl.com/lffmsd6 (edit: see note below!)
3. Buy a Jaguar branded and boxed slave - there are five on eBay at the moment: http://tinyurl.com/q9kwkzr

I was at Stoneleigh this morning and happened to be chatting to a vendor who specialises in original ap Lockheed parts. He agreed the repro slave cylinders are a problem because of the imperial/metric conversion done in China but says it is a lot worse than that as the replacement ap Lockheed seals do not work properly in the repro slave castings! I was told to avoid any slave or master cylinder that had 'Lucas' cast into it. The genuine items should only have the seven digit casting number. I bought his last 80mm Lockheed clutch slave as a spare. He had plenty of 95mm one though.

I have a further solution, following my documented clutch slave failure in France in 2011, (my repair to the damaged seal sorted with the 2 Euro bicycle puncture repair kit -see "Broken Clutch Pedal" response in June 2011), and that is to get your old slaves restored by Past Parts in Bury St Edmonds. I have no allegiance to them - just a very satisfied customer.

All my old slaves and brake masters have been resleeved in stainless by them and kept as spares. Not only are these accurately machined, but I can safely store and use these without any concerns on future corrosion.

regards,

Dave
1967 Series 1 4.2 FHC

Thanks for your advice - have managed to find a genuine Jaguar slave, so will keep it as a spare unless I feel an urge to crawl underneath and skin my knuckles over the winter.....

There is an alternative option which is the new Lockheed version which SNGB offer ? it?s about ?10 cheaper than the Jaguar one but about ?10 more than the repro ? part number C21470#.

Hi my 3.8 has the long version of the slave cylinder not the short one, is there any problem with this? It has always worked well but now has just started to weep.
Adam

All 3.8's and early 4.2's had the short 80mm slave. This was then changed to the longer 95mm hydrostatic version for a time and Jaguar then reverted to the short one, if that tells you anything. No real difference other than the hydrostatic requires no adjustment for wear. If you decide to opt for the short version you will need the return spring, bracket and possibly the correct push-rod if the shorter 3 1/2" hydrostatic one has been fitted. I have replaced the hydrostatic slave's on both my cars for the short ones as they are a) correct for the year and b) I like the ability to adjust the clutch bite point to suit me.

NB:
C9798 = 80mm slave push-rod
C24148 = 95mm slave push-rod

My Pushrod is 95mm long and a return spring was fitted. So i can just use the short version?

Adam

Yes. Surprised you did not have problems with the spring fitted to a hydrostatic slave as the spring will work against the hydrostatic valve and play havoc with the setting.

No valve inside cylinder, part no 3232-648c its just the same parts as the small one inside.

Adam

adam wrote:No valve inside cylinder, part no 3232-648c its just the same parts as the small one inside.

Adam

Agree. There is a fair bit of confusion about clutch hydraulics as there is/was with 3.8 brake hydraulics.

The long cylinder uses a spring to return the piston to mid-travel and then stops acting as a spring when it becomes coil-bound and the hydraulic action is 'static' thereafter. It is not like the SU carb springs for example, which retract the throttles against a stop. It is just a way of ensuring a reasonable starting position for the clutch action and is adjusted by clamping the teardrop shaped anchor plate to a point that suits clutch bite.

Thanks for the help. I will get a genuine jaguar short slave cylinder and adjust it as per book.

Adam

The spring in the long slave acts like a valve to control the position of the push-rod relative to the fork. If you put the external spring in place the hydrostatic action will be lost because the two are fighting against each other. I drove a car with such a setup and it was terrible - sometimes the clutch would go to the floor and had to be pumped to get it to bite; other times it was OK. Removing the external spring solved the problem immediately. They had replaced the 80mm slave with a hydrostatic one, not realised the difference and put back the spring and bracket. Jaguar probably realised themselves it would cause confusion and reverted to the short one from December 1968 until the end of E-Type production:


Details on initial setup of the hydrostatic slave are sparse to non-existent with only the following information "On later cars an hydrostatically operated slave cylinder is fitted and, as normal clearance is automatically compensated, no clearance adjustment is required. The new slave cylinder can be identified by the absence of a return spring"

Haynes provides this information (p.125) : adjust the gap between the operating rod attachment hole and the centre of the fork end to 19mm (0.75"). Did this, works fine. :)

I have just finished putting on a short slave cylinder perfect. Because of the great advice from forum members who cleared up which cylinder would work, job done.

Adam