1973 C10 "The Purple Truck"

[mrk5]

Today I swapped in a leaner set of rods in the primary side to see how the MPG's and drive ability are affected. First road test is good, no loss in performance, no detonation. Be interesting to see how the MPG ends up on this tank; I've been running around 12mpg.

If I want to go leaner after this, I will have to do another jet change as I just installed the leanest rods I have.

I thought while I was at it I would try leaning out the idle mixture a 1/16 turn. Nope, this engine just really like the factory mixture the Street Demon came with.

 

[mrk5]

What are some concerns or things I should know if I want to get the A/C system charged?

The guy we bought it from replaced the compressor with a junkyard unit. I know the clutch engages. Everything looks to be in good condition. My plan is to take to the mechanic we use for the company vehicles and have them see if it can be charged. I've never had A/C in one of these square body trucks. Can you still get R12? Does it have to use R134 nowadays?

 

[ZooMad75]

Unless you want to sell your first born for the R12 cost, they will fill it with R134a.

It will work fine. We've converted many down here. Ideally you want to change all the rubber o rings out, new compressor and accumulator/dryer, but we've just thrown the conversion fittings on and charged it too.

On a regular cab truck the R134a will still freeze you out.

 

[6872xtc]

I am not positive, but going back to your previous picture, it looks like it is an orifice tube system. If it is, then what @ZooMad75 said is correct. My '90 and Pat's '78 work fine with 134A. I know that the '72 trucks weren't orifice tube systems, but I just don't know 100% on the '73.

 

[imiceman44]

I am not positive, but going back to your previous picture, it looks like it is an orifice tube system. If it is, then what @ZooMad75 said is correct. My '90 and Pat's '78 work fine with 134A. I know that the '72 trucks weren't orifice tube systems, but I just don't know 100% on the '73.

73 and up is orifice tube

 

[ZooMad75]

I'd also recommend putting a new orifice tube in at that time. You would be amazed what 46 years of use will end up in it.

 

[mrk5]

The hoses look new to me, so I'm wondering if more than the compressor has been changed out.

 

[mrk5]

Took a look at the brakes today.



One of our employees thinks he seen rotors with the groove cut in them like this in manufacturing. I think he's right because it's on both sides and it's uniform. I can't see how the pads could have done it.

Anyone think I need new pads?

 

[imiceman44]

Took a look at the brakes today.

View attachment 297549

One of our employees thinks he seen rotors with the groove cut in them like this in manufacturing. I think he's right because it's on both sides and it's uniform. I can't see how the pads could have done it.

Anyone think I need new pads?

That's balanced.
It's normal.
I even have seen inserts in the slots for balancing weights

 

[skunked]

Mine look like that on Sancho too. Make sure you measure the thickness of the rotor, they're heavy duty (thicker) rotors and light duty if you're replacing them.

 

[mrk5]

Mine look like that on Sancho too. Make sure you measure the thickness of the rotor, they're heavy duty (thicker) rotors and light duty if you're replacing them.

I did measure, and they are the heavy duty 1-1/4" thick. I figured they would be because the original owner used it for hauling a camper and it has a receiver hitch, 7-pin round plug, and old-school hydraulic brake controller.

New wheels and "new" tires.





15x8 Cragar Nomad wheels with 3-3/4" b/s, 265/75r15 tires, and center caps from a 96 Astro Van. As my wife says "no more grandpa tires"

 

[ZooMad75]

The groove is normal. Many had that back in the day.

 

[mrk5]

The groove is normal. Many had that back in the day.

I figured it was a "back in the day" thing. Previously my back in the day trucks have been all drums so this was a first for me. I'm thinking this means these are probably the original rotors. I hope not the original pads, but then that would mean this thing has only flipped the odometer once.

 

[ZooMad75]

I don't know if I'd go through the effort of turning the rotors the way they look. I know some replacement parts aren't quite like the originals, but I don't think you'll be towing or stressing those brakes much.

If they don't have a big lip or nasty grooves I'd scuff it with coarse scotch Brite in a non-directional pattern on both sides and pad slap it. Just check your thickness and make sure they aren't at the minimum thickness already.

 

[imiceman44]

I don't know if I'd go through the effort of turning the rotors the way they look. I know some replacement parts aren't quite like the originals, but I don't think you'll be towing or stressing those brakes much.

If they don't have a big lip or nasty grooves I'd scuff it with coarse scotch Brite in a non-directional pattern on both sides and pad slap it. Just check your thickness and make sure they aren't at the minimum thickness already.

Same here

 

[mrk5]

I don't know if I'd go through the effort of turning the rotors the way they look. I know some replacement parts aren't quite like the originals, but I don't think you'll be towing or stressing those brakes much.

If they don't have a big lip or nasty grooves I'd scuff it with coarse scotch Brite in a non-directional pattern on both sides and pad slap it. Just check your thickness and make sure they aren't at the minimum thickness already.

I was thinking about that also. I don't think they are badly grooved. To be honest, I'm more concerned about the calipers because if the truck has been sitting for long with the pads nearly wore down, the piston may need to be cleaned up. I have a feeling it's been years (decades maybe even) since there were fresh pads on the truck.

 

[mrk5]

Although in fairness, I should confess I may end up with new rotors and/or calipers just because I like shiny new parts. It's an addiction/problem I have.

 

[6872xtc]

Although in fairness, I should confess I may end up with new rotors and/or calipers just because I like shiny new parts. It's an addiction/problem I have.

While I understand this statement, I would be very hesitant to get rid of them unless I found something not made with Chinese steel. You have good old American iron there! My '72 C10 still has a set of those, just cleaned up when I did brakes, not even turned.

 

[imiceman44]

While I understand this statement, I would be very hesitant to get rid of them unless I found something not made with Chinese steel. You have good old American iron there! My '72 C10 still has a set of those, just cleaned up when I did brakes, not even turned.

I agree.
They even look pretty clean other than some surface rust

 

[ZooMad75]

Looking closer the rotors have been replaced. There isn't that much rust/scale on the edge of the rotors/fins. I've seen some in the shop, even around here in our dry climate where they are horribly rusty in that area after a few years.

But if you want to pop for some fresh parts go for it.