Some time ago, I had a total foot brake failure! The fluid level was down and a top up made no difference. I changed the seals in the master cylinder, bled the brakes and achieved a hard pedal. All appeared well. I have now driven some 100 miles and find little if any brake servo assistance and the fluid level has decreased again. I am fearful that fluid is leaking into the servo unit and then via the vacuum system into the intake and then causing a blueness to the exhaust. Any suggestions? Can the servo be recovered? AlecG.

 

SNG Barratts can do a complete rebuild on your servo. That's what I did and it's like new. Otherwise fit a Lockheed 4 to 1 ratio. This will require some pipework rejigging. Not a terrible job & a lot cheaper.

Barratts rebuild.

 

Do you know if anyone does a re-build kit? AlecG.Thanks for the lead!

 

I think the original version from SNG Barrett is on an exchange basis but when I replaced mine several years ago I bought the higher boost version which is £162 cheaper than having an original version. Gives you a better feel on the brake pedal. ie not so much push for the same power. Considerably cheaper and you get to sell yours to someone else on Ebay who wants to take the time to rebuild it or use it as an exchange unit and save £180.

Higher boost version 4:25:1 £207 https://www.sngbarratt.com/English/#...9-c1e045556d59

Original version with exchange £369 plus £180 which you get back. https://www.sngbarratt.com/English/#...ake%20servo%60

 

I have the impression that rubber components can survive for decades submerged under brake fluid. But, if the are ever exposed to air, they subsequently degrade quite quickly. As a result, after one component fails or someone is careless changing/bleeding the fluid, another failure soon follows.

 

It is almost impossible to get an original MK1&2 Jaguar brake booster overhauled in Australia.
For Australians, the PBR VH40 brake booster is ideal on MK1 and MK2 disc brake cars.
Drum braked MK1s can use the PBR VH44 booster which is lower pressure. The VH40 makes drum braked cars too touchy and savage on brake application.
I understand Jaguar used some sort of restrictor in the original booster output when fitting it on drum braked cars

 

I decided to investigate the brake servo and found a worn seal and a broken spring support. New seals were obtained and another old servo off you know where that I cannibalised for necessary damaged parts. This seems to have done the trick, although I have not driven it very far due to me acquiring three broken ribs! I would also add as an aside that a previous owner had welded a plate over the bolts securing the protective cover for the servo. That took a lot of removing with one of those reciprocating saws, and I had to butcher the cover where there was insufficient access! I hope the saga has ended!