Modifying mk1 pedalbox for dual master cylinder...

[sandman]

Is it possible to modify the Mk1 pedal box so a dual circuit master cylinder will fit?

Is it just a matter of increasing the hole?

Any special things one should pay attention to?

[steady eddie]

Is it possible to modify the Mk1 pedal box so a dual circuit master cylinder will fit?

Is it just a matter of increasing the hole?

Any special things one should pay attention to?

That's all I did increased diam of hole but seem to recall also had to alter the length of the push rod not sure if longer or shorter.

May be depends which master cylinder you use, which have you in mind?

Eddie

[scooperman]

This is not what you are asking, but anyway here it is. I previously tried a dual master on my race car and did not like the results. For the dual master, yes, my recollection is that all I had to do was to enlarge the hole in the pedal box and bulkhead.

Later, I made one pedal box out of two, to put two bean can masters on a balance bar, and this has been excellent. My race car is RHD.

[Vegard]

You cannot enlarge the hole as there is a reinforcement steel section which is in the way. You'll need to remove and reweld this as well. But hey... You can do it. I just found a newer pedal box

[scooperman]

Vegard, yes I remember that now, the master was bigger and it interfered with the pedal box. I had the pedal box out and apart on the bench, and I modified the pedal box frame to fit. This was years ago, late 70s, I think I ran a hole saw down into it for some distance to cut into that bracing, and then did some persuading with a hammer. I eventually got it to fit but I think I finally had to remove the bellows on the pushrod because it rubbed. Also, when I got it all in place, the pushrod length was a bit too long and the master piston would not return fully.

The car hasn't moved in years, I can't even get the door open now because of all the stuff packed around it. Maybe I can reach in the door and hold a camera under the dash to get a photo.

[sandman]

Why would I need to alter the pushrod? Is the angle of the pedals (or more correctly the "pivoting arm" different on Mk1 and Mk2++ (or pedals/pedal boxes for dual circuit masters)?

Btw, I am trying to fit a new "yellow band" master cylinder.