Hello! '67 vintage brakes question!

[Nasadowsk]

First time caller

I'm looking at getting an old IH truck, to keep my lonely '40 H company, and have settled on a few in the area.  One's an adorable dumper, which looks cool, and is decently chonky.  It's a '67, is apparently 6volt (?).  Bad news; "ran when parked", but worse: hydraulic brakes.  I know a lot of older vehicles are single circuit, but by looking at the under hood photo(see attached), I can't tell if this one is.  It LOOKS like there's one thin line out of the master cylinder, but that thing the left of the cylinder looks like it has a pretty serious pressure line coming out of it, which has me wondering if the 'normal' looking cylinder is the front brakes, and that big one is the rears.  This thing's a dumper, under 26k GWVR (but likely not buy much), and single axle but big dually wheels.

And, if it IS dual system, what's parts availability like to rebuild the brakes all around?  This would be more than a show truck, since I can register it normal in PA with no issue, and having a dumper would be useful for me.

Thanks!

[int 504]

One is brakes other is clutch.

[snoshoe]

56 and up should be 12 volt

[Nasadowsk]

2 hours ago, int 504 said:

One is brakes other is clutch.

Ok, that confirms it for me. Bummer.  I liked it, but was afraid that was the case, and really don't want to deal with a single circuit system.  Thanks for the help!

[Nasadowsk]

Ok, maybe I'm overthinking it, because otherwise really like the truck:

Is it possible (practically), to convert to dual circuit?  I think it was mandated a year or so later, but I'm not sure.

Am I just overestimating the dangers of a single system, assuming everything (seals, hoses, lines, rebuilt master cylinder/brake cylinders) is replaced with new, and it's well maintained?  I'm not going to daily this thing, but I would probably drive it a bit more than just casual/parade/show use.

Thanks for being a nag about this, IH trucks are a new world for me, so I've got questions

 

[acem]

Hydraulic single system brakes were around for many years after 1967. If you maintain your brakes properly and have a good working hand brake you should be ok.

The engine is the primary brake of a truck. The pedal brakes help out and gets you completely stopped at the end.

 

But if you want to convert, it can be done. Many school buses were dual system.

I'm assuming this is a Loadstar. 

There's an existing thread on the conversion a few threads down.