OldIHC

LLoyd, they do. If only they had been sent rotated 90 degrees... But that's being picky, I suppose. Bill

sorry about that.

Lloyd, it wasn't you. That's how they were emailed to me, sideways. So far, I have learned quite a lot from this project. Patience, respect for those who can look up something in a parts manual and tell if it is the right one or not, and how to deal with the headaches as I try to learn how to do that myself. It still looks like I might be able to swap a single master for a dual, but only on a very limited basis. The brake codes for the 1200A and the 1200C are very close. The A has a front brake code of 04105/0001/C and the C has a code of 04105/0001/D. The A has power brakes that may, or may not make a difference. Both have a rear brake code of 04204/0007/A. To me, that only suggests that you can swap the masters by changing the plumbing. If I knew the wheel cylinders were the same, I would be much more at ease about this. The numbers for the whole system, if I'm reading this right, diverge more. A is 01202/0001/5AD, C is 04001/0084/5EF and the 1500A is 04011/0329/7C. I have a feeling this is significant, but I'm not sure yet. But I am sure I have a headache again. I'll post more later, when I find out more. Bill

The A has power brakes, so does it have a booster? The difference between the two numbers on the front could be because of the difference of Power brakes and non Power brakes. Do the wheel cylinders look the same on the outside? if so, then it could be the inside "bore" is different or just a slight difference in how the cylinder is plumbed. The Divergent numbers on the whole system would not be out of line, as it takes in all components of the whole system, Shoes, drums,cylinders, lines, master, etc.
At least that is how I understand it.

Both A model trucks have boosters, the C doesn't. The 1200A has a booster mounted on the inside fender, and the 1500A has a booster mounted on the frame, under the cab. The wheel cylinders look the same, but I'd have to measure them to make sure. Bill

I would be most concerned by the volume requirements of each half. If the one with a dual set-up uses the same bore cyl as the single line than I would say IHC did the math for you and you can go ahead, if there is any difference than be wary.

Thank you, CB. That is why I wanted to find out if the wheel cylinders were the same for both of the 1200 trucks. My logic was, if the wheel cylinders were the same for both the 1200 A and C models, then having a single master cylinder replaced by a dual master would be plausible. If the single master of the 1200A and the 1500A were the same, then I might be able to safely change it over to dual as well. But I haven't been able to prove that final step as of yet. I plan on working on it as time goes by, if for no other reason, I think it would be nice to know what is safely possible.