Ferocious brakes on our M8 Greyhound

[Malcolm Towrie]

We had a problem with the brakes binding on our M8. I found the wheel cylinder bores corroded enough to restrict piston movement so the hydraulic pressure would push the pistons out but the much lower spring return force couldn't pull them back. Honing the bores and greasing the pistons with "red rubber" grease fixed the problem. With the Hydrovac booster and the twin cylinders acting on each of six wheels, the brakes are phenomal, so much so they can be a bit ferocious. A light touch is needed on the pedal. Drivers here are not used to using a light touch on WWII vehicles,so there are complaints!
Was this normal? I'm not too familiar with the Hydrovac unit. Can they fail in a way that causes this?
I have seen contaminated brake shoes cause this problem but the shoes were all found clean and dry. And all the shoes were adjusted out to give a very light rub on the drum.

Malcolm