Mk2 Brake Servo overhaul kit?

Hi guys, does anyone know where I can get a repair kit for my original '64 servo cylinder body ?

I have new kits for the Diaphragm and slave cylinder but really would prefer to also renew the gasket ( No 39 ) between the servo cylinder body/drum and its lid plus the ‘leather cup’ seal ( No 28 in service manual). This, on my car, appears to have an inner aspect of some type of rope with the perimeter clad with rubber. Not sure why the manual refers it to being ‘Leather cup’.
Is it crucial this is in perfect condition to ensure perfect functioning ? My own just has a little roughness to the rubber in one area hence my preference to renew it. Thanks in advance to any replies.

I’ve been looking for pretty much the same items myself for my 340 servo. It appears that some of the parts are now unobtainable or very difficult to locate.
I was agonising over it for several days until i saw on ebay that david menners do a replacement servo kit for £96, so i decided to order one and see how it goes. I dont think its worth all the hastle of rebuilding the servo when the cost of the separate parts where adding up to approx£70 and still some parts not located. The new servo kit for another £26 was, in my eyes a no brainer.
Ebay item number…
Last one left.

Item# appears dead…

You may be trying to find parts for the servo on the right which was the original one in my 1965 3.8S. When it developed a small vacuum leak (might be expected after 50 plus years) the shop replaced it with the type on the left which seems to be the standard work around these days. Seems to work just fine.

Try ‘jaguar mk2 brake servo kit’.
It should come up as the first one on lhe listing…

Try past parts and J and L spares here in the UK.

I contacted Past Parts and have sent off my slave cylinder to them to re-sleeve it with a S/Steel insert. Hopefully all will work out ok. Thanks for every ones input here.

I can’t find the listing but I wonder whether this kit is actually for the later servo like the E Types used.

I recently overhauled my Mk2 brakes as part of putting in a bigger engine.

I installed a later model Lockheed unit as parts for the 6 7/8" booster are not available.

I had to slightly modify the mounting points on the nacelle that holds the booster onto the inner guard. The brakes are excellent, better than any of my E types.

Hi Tony sorry for delay in my reply. Thanks for searching for the kit. As I had said in my last post the cylinder is away to be re-sleeved with a S/S insert. I have managed to get a ‘new old stock’ kit for the servo drum from ebay.

Ok. No probs. Good luck with the servo re-build.
Not fitted my replacement yet as the car is in bits for a full restoration, but hopefully we’ll both have good brakes when finished…

Hi There - I bought a Mark 2 3.8 Manual with overdrive last November but it has got a problem with the brakes - when slowing down virtually to walking pace the brakes suddenly lock on and bring the car to an immediate halt. A light tap on the brake pedal releases the brakes and off we go until it happens again. I have been told by people whose opinion I value that it could be the brake booster. Any thoughts would be much appreciated and if it is the problem, is the best replacement booster to buy a 3.0 to 1 boost ratio or 4.25 to 1 boost ratio. The main supplier is offering both. Thanks Ian W

In my experience the boost level of the original item is more than adequate. The difficulty is obtaining spares to rebuild it.

I overhauled my brakes recently when I put in a 4.2 engine.

Although my original booster worked I wasn’t happy to just put it back untouched. All I found on offer was the 4.25 booster, so I bought that.

This physically fits fine in the mounting nacelle but the bolt pattern is different so you need to modify it for this.

With the 4.25 booster the brakes work well; to be honest I can’t really tell the difference.

Hi Andrew,

Many thanks for the prompt and helpfull reply – I think I will go with the 4.25 Barratt unit and hope for the best.

I should have commented that my car has previously had Coopercraft discs and callipers fitted to the front end so the braking performance is pretty good as it is apart from the irritating locking-on condition I described.


Ian Wilkins