XJ6 Series III Pedalbox and Master Cylinder

One of the initial goals for this project was to upgrade to dual circuit brake system. I have had two experiences with total loss of brakes on one circuit cars so I am not willing to take any risks. Especially as this will be my daily driver.

I decided to go with a XJ6 Series III pedalbox with the master cylinder and brake booster in order to stick to the Jaguar components as far as possible and also since the design is perfect for this application. I don't know if it would be possible to do this conversion on a carburated car as the brake booster might not fit behind the carbs. In my case I have fitted a Series III EFI engine where the intake manifold tapers downwards leaving enough room for the booster. It will still be a tight fit for the air intake to the throttle body so I might have to move it forward later on if it has problem breathing. On a Left Hand Drive car I assume you would have plenty of room.

To fit the XJ6 pedalbox I had to cut out a bit of the firewall around the mounting holes for the original pedalbox.

This is what it looked like originally :

And this is after some cutting

The flap at the back is a piece which I cut out partially and then folded up to weld at the top to reinforce the area.

When I bought my XJ6 pedalbox from the wreckers I also bought a cut out of the firewall from the XJ6. This cutout will sit between the original brackets for the battery shelf. You can see on the left in the above picture that I had to narrow this bracket to make the new pedalbox fit. Obviously the battery won't fit here anymore so it will go in the boot/trunk.

This is what it looks like with the cut-out welded on top of the battery shelf brackets and a thick sheet metal cut and bent into shape to support it

Excuse me for the horribly looking spot welds. I had run out of gas in my disposable MIG bottle due to a leaking seal.

The three innermost bolts won't be accessible to screw in from below anymore so instead I welded three nuts underneath the cut out and will bolt the pedalbox from above instead.

I also had to move the spring for the bonnet latch as the brake booster was in the way.

The only problem now is that the brake pedal is a bit too far from the accelerator due to the pedal arm being offset to the left. I have been told that the pedal arm from a manual is straight but haven't been able to source one yet. One wrecker laughed at me when I asked if they had any so it might be a long search. If anyone out there has one for sale then please leave a comment to this post.

In the next post I will show how I built a bracket for the alternator