HJ 45 Drum Brakes

adjust the back brakes. the auto adjusters have probably siezed

But before you attempt to adjust them remove the rear drums and clean and lube the adjusters with something like coppercote or neversieze.
If the drums are 'lipped' and won't slide off over the shoes you will have to get a piece of bent fencing wire and push in through the adjuster hole and push the spring tab back to allow you to turn the adjuster backwards to "shrink" the shoes inwards away from the drums. Get a mechanic to show you how if this doesn't make sense.

drum brakes need regular adjusting or they turn to crap
I had the brakes adjusted 3 times in 5 years on my Nissan E20
they worked pretty well afterwards

I had the drums on my HJ47 machined to fit the shoes and the fluid replaced. I could stop in no time for years after. Adjusted maybe ones a year. I don't mind drum brakes at all.

Reiner

From memory the 76 model had two reservoirs on the master cylinder the big one was the front wheels and the small one fed the rears. Re-building this by replacing the rubbers and sanding out the bore with emery paper will not cost much. Because the fluid was old it would be full of moisture causing internal rust everywhere. I reckon you should re-build the wheel cylinders as it doesn't cost much if you DIY. Cleaning out the crap and putting kits in them should cost about $20 per wheel for the rubbers, or you can buy new wheel cylinders from an after market shop like Autobarn and they are quite cheap. Make sure you grease the adjuster threads and do not puncture the covering rubbers when you put them back. I owned a 76 shorty then a 79 troopy and went to Fraser Island three or four times a year. This means I re-built my brakes many times as the salt got to them. Don't use the transmission brake to stop the vehicle, it is only bolted into the back of the aluminium transfer case with small bolts making it quite weak for this purpose, you can rip the back off the T/case.

Thanks all of you, a lot of great info.

Yes, I had to adjust the brakes and also I had to invert a wheel cylinder that was installed up side down on one side of the car. So I had an opportunity to inspect just that cylinder and it looked very good inside. It doesn't leak either. The brakes now work perfectly, with the front brakes locking up just before the rear do. I just wonder why that one cylinder was up side down. That means that only one shoe was being pushed towards the drum. Funny stuff. The cylinders on the other side were mounted correctly, one pointing upwards, one downwards. Anyway, it's all fixed and going good.

And no, I wasn't using the tailshaft brake to stop the vehicle!

Thanks guys.