I want to replace my rear calipers with more modern, less expensive, more available, less troublesome units. I'm not building a hot rod. I've searched this forum and have found indirect references which seem to imply everyone knows about the upgrades. Well I don't. References are made to "xj", "xj6" and "xjs" calipers which are direct fits and ones which need adapter plates and ones which use some of the old parking mechanism and others which use all the new parking brake. Apparently there are multiple solutions. What year and model Jaguar rear calipers will work and what must be done to complete the conversion?
That is my primary issue however I'll take this opportunity get input for the other brake system upgrades I'm planning..... Volvo 240 4 piston front calipers and a recent / present Girling servo which is suppose to be a direct bolt in replacement. I've always installed a proportioning valve in upgraded braking systems in my old cars but have yet to need them since I install larger front brakes and the balances have been good. I'll skip the valve if someone says I won't need it. Also is there a dual system master cylinder which can easily be fitted to this '64 Mark 2 vertically mounted arrangement? Is anyone's DOT 4 fluid OK with all this stuff? The first question is my primary issue.

 

Anyones DOT 4 ~ DOT 4+ fluid is fine with all elastomers in the system.

I'll leave the rest to someone that has actually done it.

 

I've fitted Jaguar 420 rear brake callipers to my currentl MK2 project, to fit these you need longer mounting bolts and to use some washers to centralise the calliper.

Otherwise you just fit the MK2 handbrake callipers and the 420 handbrake calliper retractor fork (the brass sprung piece).

I understand that the 420 rear callipers are the same as E-Type Series 2 and 3, some of the later S-Types (original 1960's) and XJ6 Series 1 and Series 2 as well I believe.

Its a fairly simple bolt on conversion.

I've also fitted the 420 front callipers to mine although you need 420 uprights so the Volvo 240 upgrade might be easier to do although you need the correct callipers (as some Volvo 240's had vented discs) and I believe you also have to turn the discs diameter down slightly.

Another option is S-Type (original 1960's) front callipers which fit the MK2 but have more standard piston arrangements with the seal in the calliper and the piston sliding on the seal (albeit the pistons are specific so can be more expensive).

Regarding the master cylinder, i've fitted one from a Jaguar X300 XJ6 to mine but its not straightforward as you need to modify the bulkhead, repositon the battery and wiper motor and either change the brake pedal for one from a LHD X300 or somehow modify a RHD one to crank the otherway.

As with all things anything is possible but how much work involved involved is usually the issue.

I've not put mine on the road to see how all the modifications go but I would assume having 420 brakes front and rear should be reasonably well balanced and its just the master cylinder that will be interesting to see how it performs.

 

This is one of the rear callipers fitted to the car:



This is the master cylinder conversion and more details on what I did are here: https://brm-forum.org/thread/212/jag...&scrollTo=1649

 

Thank you Homersimpson, as you said the series 1 XJ6, '67 and '68 420 and series 2 and 3 E-Types have the same real calipers. That explains why I saw so many models as donors for conversions.