Brake Master Cylinder 2

(Lou) #1

List: The master brake cylinder on the 71 XJ6 needs replacement. A new unit is $450-$500. I found a company that supposedly offers rebuilt units for about $120 but the picture of the unit does not look like mine. See photos attached. And then XK Unlimited offers a rebuild kit for about $20.

I believe that the professionally rebuilt units are resleeved, which I am sure is superior to the self-rebuild kits which are new gaskets. I would not hesitate to purchase the rebuilt but cannot find one a1971, which looks different from those for other years offered. See photos attached

Has anyone used a rebuild kit?



(Paul Breen pay palled it) #2

My 1972 is the same as pictured. I had mine rebuilt by a specialist. These have a double diameter bore - two different sized sleeves were fitted. They are not available on an exchange basis and are quite rare. Others I know have converted to later units. My brakes are great - like a modern car.

(Lou) #3


Thanks for your response. Could you advise the contact information for the specialist?



(Paul Breen pay palled it) #4

Hi Lou, my guy is in Carlton - a Sydney Suburb. I am happy to provide detauls but there must be someone on your side of the drink that can do same. My case was somewhat worse than I shared: two siezed pistons and old bronze sleeves that had to be “burned” out. New sleeves are stainless steel. Paul

(tony) #5

I had mine sleeved in SS and re-kitted for about $200.

Paul is right, they have a dual diameter

only a proper specialist can do this job properly.

The company that makes the equipment and exports it worldwide (Halray) is based in Australia

If you are in USA, there is a major brake rebuild company that does them correctly, I cannot the name, others can advise…something or other “Hydraulics”

(motorcarman) #6

WHITE POST restorations will sleeve/rebuild the cylinder(s).


(Lou) #7


Sorry, I did not realize your location. But…you never know :slight_smile:


(motorcarman) #8

Since your location is also a mystery, we can only advise GENERALLY!!!
I am in TEXAS USA but I send cylinders to White Post Virginia every few years for refurb.

(Lou) #9

Thanks, I have heard of them, although I don’t recall for what.

And I am in Scranton, Pennsylvania, birthplace of the Vice President.


(Robert Wilkinson) #10


Sorry to inform you, but Biden is no longer the vice president. You wouldn’t believe what has happened since. Best to ignore it if you can.

Just a though about the master cylinder…not sure how original you desire, but you can substitute a Series 3 master cylinder relatively easily. The advantage, besides the integral reservoir, is the savings in sourcing the part. There is much info in the XJ archives about making the swap.

(Ian Irving) #11

And if you decide to go to the series 3 unit, get one from a RHD car, the pipe runs are much easier, no tight bends in an awkward position.


(Robert Wilkinson) #12

I wonder why Jaguar didn’t do that?

(Lou) #13


Thank you for the suggestion. I have always maintained the cars originality, although I see that becoming more difficult as time goes on. So for the moment I will work with the original unit.


(Lou) #14

With regard to the brake system. From what I have seen of the brake system, it appears to be a dual system; separate lines for the front and rear. Is there any attempt to balance the the two systems to prevent one from locking up before the other?


(Lou) #15

Although he is no longer Vice- President, Mr. Biden is referred to in that way here as a form of respect.

Interesting, Hilary Clinton’s father was born in Scranton and the family still maintains a cottage not far from the City at Lake Winola.


(Robert Wilkinson) #16

The braking force is balanced (some say not enough to the rear) by means of cross-sectional area of the front versus the rear caliper pistons, Lou. The hydraulic pressure is the same, as is the area of the front and rear pistons in the master cylinder. These do not change between S1 and S3, but the S3 master cylinder has an integral reservoir.

My remark about Joe Biden was an attempt at humour. I respect him a great deal to be sure, and wish he were still VP or, better still, the President.

(Frank Andersen) #17

Not too sure about that, Bob - never measured the pistons…?

Methinks they have the same area - to cater for a fully laden car, and driver discretion called for…?

xj6 85 Sov Europe (UK/NZ)

(Lou) #18

Things have slowed here sufficiently that I can begin work on the master cylinder rebuild. Got out the shop manual, which has a complete exploded diagram of the unit.

My cylinder is not what’s in the manual. Turn it around? Upside down? The it came to me.:innocent: The manual is for a right hand drive. My car is left. Not many parts have that issue.