Making heads or tails out of my IIa brake system

[jsonova99]

So my master cylinders gave out causing a nice paint stripping leak all through the driver side footwell. Anyway, everything in the hydraulics was looking pretty rough so I decided to do a modest refurbishment of the whole system. Anyway, when I pulled the front brake drums I noticed that I didn't have the typical 10" drums that a 67 88" IIa should have. I have 11" drums with the 109" style wheel cylinders (already bought a IIa kit for an 88"). I haven't pulled the rears yet to see if I have 109 style brakes on the rear which would take the 10" IIa style front wheel cylinders so that my kit wouldn't be a total waste.

Anyway, what really has me confused is that my front wheels have two wheel cylinders per wheel, one on top and one on the bottom. I thought that there should be a single wheel cylinder with a pivot on the bottom. This two-cyliner setup does not show up in my IIa manual. I am new to drum brakes, so bear with me.

Any thoughts on this? I assume that I just need to buy 2 pairs of wheel cylinders per wheel up front (I'll figure out the rears this week). I'd just like to understand if this is a common setup or if somebody has done something custom to it at some point in it's life.

Any help or thoughts would be greatly appreciated.

 

[jsonova99]

I think I figured it out since I have 3" brake shoes. It looks like I have the brakes of a 2.6l 109" or stage 1 V8. My best guess is that somebody swapped the front axle out. Way overkill and making this job unnecessarily expensive and complicated.

 

[jsonova99]

For the series experts out there, can the brakes be switched back by simply changing the back plate or are there more components behind the brake plate that might be specific to the model? I'm not sure if some previous owner just upgraded the brakes or actually swapped the axles out. The drums are pretty worn so my thought is it might be cheaper to convert back to the standard 10" brakes sine everything you need comes in a kit. These brakes are overkill and by no means needed to stop this thing.

Not sure I'd do this just trying to understand if it's as simple a swap as I think it is or not.

 

[singingcamel]

Yes , you'll need to change the backing plate, and change out the drums as well. evry thing else should bolt right up.