Hi all.
Well, I got a bit more done. I started at the compressor and pulled out all the air lines, working back to the reservoir.
Most of the ones under the cab are fine, just rusty. Any that were under the tray are pretty much stuffed.
The 1/2" line from the compressor back to the reservoir was mostly good. I'm just a bit concerned about the last 6" as there is a 90° bend and where the metal was stretched when it was formed, it is deeply pitted.
I don't want to replace the whole line as the rest is really good, so I think I might just cut the last foot of it off, make a 90° bend in a new piece of 1/2" pipe, and put a joiner in.
Better a few dollars for a brass joiner now than a blown air line and no brakes later.
There is another smaller line running from the governor back to the tyre inflation valve. I had to totally replace this line as the 1/4" pipe just collapsed when I tried to undo it from the valve.
There was another short 1/4" line running from the inflation valve down to a tee on the end of the air reservoir. I had to replace this as it had a section missing where it went through the chassis rail.
I was able to get all the lines that connected to the reservoir undone without breaking anything. The air reservoir is held in place by 2 lengths of 5/16" rod that wrap around the cylinder and then go through the chassis rail,
where they are threaded and have standard UNF nuts to pull them tight. I bought a die nut and was able to clean all 4 threads before undoing them. It made it very easy, but I still managed to snap one off.
When I looked at the broken end, it was rusty part way through so I think it was already cracked. When I replace the tank, I am thinking of making a set of straps out of 2mm steel, about 40mm wide.
I'll glue a strip of conveyor belting to it and wrap it around the tank. I'll cut and shape a couple of thick blocks to go between the tank and the inside of the chassis rail and weld a section of threaded rod to each end of the straps so I can do them up, similar to the original system.
I won't be putting the lines and tank back on just yet. While they are out of the way, I am going to clean and repaint the inside, outside and bottom of the chassis rails for as far as I can reach.
Here's a pic of the reservoir before I started work on it.
This is the over-pressure relief valve. It wouldn't move at all and there's no way it could have done its job.
When I pulled it apart, I found that they had fitted it with the vent hole facing up and the paint had run in and blocked the rod.
This is what the reservoir looks like now.
I cleaned it back to bare metal with a wire wheel on the grinder, then gave it a coat of rust converter. This showed up quite a few sections I had missed, and it took 2 more goes with the wire wheel and rust converter before I got it all.
Once I neutralised it, I etch primed it, then gave it a coat of underbody black. I think this should help protect it, as its pretty exposed to rocks and scrub.
I haven't decided if I should paint the chassis rails, air lines and reservoir in Olive Drab or black. From what I can tell, the entire truck used to be Deep Bronze Green.
However they did it, the original paint is still in great condition under the newer Olive Drab.
For now, I think I will just etch prime everything and coat it with underbody black. If it doesn't look right, later when I get the tray off I will overcoat it in whatever colour I finally decide on.
The next step is to remove and clean or replace the pipes going from the back of the reservoir. these run up the drivers side chassis rail and feed the winch control, high/low 4wd lockout, the brake pedal and trailer brake control.
These look pretty good, so barring any mishaps, they should just need a clean and sand. From there, it gets tricky.
The line from the brake pedal to the actuator and master cylinder looks good, but the lines running back to the tractor protection valve have been replaced with lengths of compressor hose and normal old hose clamps.
I'm pretty sure the originals used to be 1/2" and I can't get any of that for a while, so I might just cap off the lines for now so I can test the front half for leaks.
The lines running from the winch control to the actuator cylinder on the winch have to be completely replaced. They have rusted through and there is about a foot missing from both lines.
Luckily for me, there is enough left for me to copy when I get my 3/8" pipe.
When I sit under the truck facing the rear, just above and behind the air reservoir and above the transfer case is a cross member. Across the top run the 2x 3/8" lines for the winch controls.
Below that runs a 1/2" line that takes air from the reservoir to the controls up front. Below that is the remains of another 3/8" line. Its rusted through both ends and I'm not sure what it originally was.
There's nothing in the chassis rails on either side that would have connected to it. The only thing I can think of is that it may have been a line feeding the actuator on the back of the transfer case that locks out 4wd.
If it is, it must have originally run down the passenger's side chassis rail, across the cross member and then down the driver's side rail until it connected to the flexible line on the transfer case.
The line currently connected to the back of the transfer case appears to be a replacement as it is copper and looks to have been made of soft rolled tubing as it is pretty bendy where it runs along the rail towards the front.
Most of the original tubing was hard drawn steel, so pretty straight.
One job I should have done before painting the air reservoir was to clean it out. I had about a cup of slimy jelly run out when I removed the seized drain valve.
There was no smell, other than a sort of stale oil odour, which I think is a good sign. I know from past experience with the old steel scuba tanks that corrosion in a steel tank gives off a nasty acidic smell and I didn't notice that.
I'll have to clean it out and borrow the bore camera from work to see inside. Any idea what the best thing to clean the inside would be?
Greg.
