73 C60 Flat-Dump Truck

[Bigdually]

I bought another square medium duty truck, this makes number 3 now. I may have a problem

I've been needing a way to haul stone and dirt lately, and I've always wanted a dump truck ever since I was a kid. A guy I go to church with mentioned that he had an old Chevy dump truck that needed brake work, so I began asking him about it and I discovered it wasn't just any old Chevy. It was a 1973 C60 with a 350, 4 speed with a 2 speed rear, and a 10' Midwest flat dump body. Twice the functionality in one truck!

It appears to have originally been a power company truck, there is leftover evidence of the front extended bumper having housed a huge PTO driven winch. Other than a few little dings, it's a pretty solid truck! The bed is very solid and seems to work great. The 350 runs beautifully and sounds great too. I believe it has 73,000 original miles on it.

It doesn't have brakes. It's a hydrovac truck, so I'm not sure at the moment exactly what's wrong since I don't have it home just yet. It could be as simple as a blown line or wheel cylinder, or a bad master cylinder. I'll know more once I get it home and begin some diagnosing.

[Bigdually]

The C60 made its way home today, borrowed a trailer from my brother in law and my father in law and I brought it to my dad's place where I work on most of my stuff in his shop. I also store my parts C70 over there.

It runs and drives fairly well from what I can tell, can't go too fast because there isn't even a suggestion of brakes, service or parking. Dad, who has gone in on the truck with me because he has as much use for it as I do, has ordered the Battle Born Brakes F550 booster and master cylinder conversion kit. Those parts should be here next week.

I power washed the truck and I'm not sure if it's better or not. Definitely less green, but also much less paint on it. Mostly the paint came off of the hood and fenders, but that's not bad as I plan to swap the fiberglass tilt front from the C70 onto the truck if I can. The hood and fenders on the dump truck are pretty rusty and the front valance under the grille is mangled.

Hopefully I'll have more updates as I dig into the brakes in the coming week.

[Bigdually]

I have the dash cluster pictured that I am considering swapping into the dump truck, it's out of the parts C70 I have. It has the cool medium duty tach/gas gauge combo and an air pressure gauge. The dump truck has the standard large fuel gauge and a blank on the lower left hole.

Does anyone have a factory early style (73-80) vacuum gauge for that lower left gauge hole they'd be willing to part with??? Let me know, very interested in finding one!

[C10 - C90 Bill]

Interesting truck.

Keep us posted on it.

[Bigdually]

Originally Posted by C10 - C90 Bill

Interesting truck.

Keep us posted on it.

Will do! I hope to be making progress pretty quick to post about.



Got the truck stripped down to a flatbed this evening and moved it into dad's shop. I wanted the sides off so I can use the bed as a place to put parts as I work on it. The box from Battle Born Brakes showed up and the new booster and master cylinder look nice. Also got their proportioning valve to keep the 50/50 braking that the truck was designed to have.

I have found and ordered wheel cylinders for the front and all 3 rubber hoses, but I can't seem to find rear wheel cylinders. If anyone knows of a source for them I'd be grateful for the info!

[Bigdually]

Some progress this evening, removed the ugly extended front bumper. If I can surgically remove the half mile long bead of weld from along the top junction with the diamond plate I'll try to reuse the factory bumper in its correct location for now.

Found a solution to the 20" split wheel issue, and no it won't be putting these really sweet polished 22.5s on. Those will go on my 89 GMC, the link to that truck is in my signature. I will in turn be using the steel 22.5s from that truck on this one.

I had looked extensively several years ago and nobody made aluminum 22.5s in the GM small 10 bolt pattern, but Dad was doing some looking for stock 22.5 steel wheels for the dump truck and came across the polished aluminum ones.

[Bigdually]

I was able to dig into the rear drums yesterday and get measurements and numbers off of the wheel cylinders. They were the only things I couldn't source for the truck but after I cross referenced the casting numbers I was easily able to order 4 new wheel cylinders, 2 left and 2 right.

Once those arrive, I'll have every single piece of the brake system that handles fluid brand new. The shoes and drums are in good shape, so they'll stay in service after a good cleanup.

[Bigdually]

All my brake parts are in and I've verified that they all at least look like what I need. Took the front drums off this evening and discovered all the wheel bearings up front are shot. Pitted and nasty from water intrusion, shiny metal flakes on the driver's side. I'll call the local bearing supply place tomorrow for some new bearings and wheel seals.

Also discovered the passenger side kingpin has a good amount of play, I'll have to find a kingpin and bushing set for it. Such is life when you're dealing with a 52 year old truck, not too much of a surprise.

[Bigdually]

No physical progress on the truck today, but I did source NOS Delco NDH bearing sets for the truck along with a set of wheel seals, all on eBay. Far cheaper than anywhere I priced locally and all far superior made in USA parts.

Got a set of gauges on the mail today too. I found these while searching for a vacuum gauge. Rather than cannibalizing the set from the parts C70 I figured why not just use these instead? I'll take them apart and carefully clean everything, replace the bulbs, and get them in the truck. I have always strongly preferred the stock tach in any 73-87 truck over the huge fuel gauge.

[Bigdually]

I've made some progress over the last couple weeks just working on it a few hours in the evenings after work when I can.

So far, I have:

Completely removed all the old braking system. Lines, hoses, everything. If it handles fluid it's going to be new.

Installed the firewall mounted booster and master cylinder, hooked up the brake pedal and bled the master. These trucks are big, but working under the dash still sucks and requires awkward contortions. Hooking up the brake pedal pretty much sucked.

Gotten the right rear corner cleaned, lubed, and rebuilt with new wheel cylinders.

Started making new 1/4" lines to run everything.

There's been a ton of little things along the way that have taken up my time, like modifying my brand new Chinese flare tool so it actually makes a usable flare, getting new coolant bypass hoses because I touched the ones on the truck and they started leaking, and other "old truck things." One of these days I might end up with a truck that will roll and stop under its own power again.......

[Bigdually]

Not much has been done this week due to work and other obligations, but in my travels I did stop by a small junkyard at a rural towing company and scored a mostly unmolested gauge bezel.

A little scrubbing and a silver marker and it's ready for when I put in the "new" gauges I have waiting.

[Bigdually]

Slow progress has been made over the last couple months. The front axle ends have been completely rebuilt with the new kingpins and bushings, all new wheel bearings and seals, and new wheel cylinders. Thats really about all, I had to reorder rear wheel seals due to receiving the wrong ones initially. Have those and now I have to finish the rear.


A question for anyone who may be reading - What's the spec for gear oil for the T-150 2 speed rear? I'm assuming 80w90 gear oil but I don't know if there's yellow metal inside that would get hurt by the sulfur in the modern stuff.

[Bigdually]

Got the final assembly of all 4 corners done and now I'm almost completely wrapped up with the brakes, at long last. I have to run the lines out to each side of the rear from the Tee fitting at the diff and then bleed the system. With any luck one more good evening of work will have the brakes working.

Dad's shop look like a bomb went off all around the truck, somehow I think every single tool in the place is on, beside, or under the thing right now.

[Bigdually]

At long last the brake lines are ran and the system is holding fluid! I was off work today and had a good amount of time to get some stuff knocked out. It's not an overly beautiful job, but this is a work truck and it just needs to be functional and safe.

Had a minor setback when the left rear began pouring brake fluid out from inside the drum. Turns out I made a mistake on one of the new wheel cylinders and installed the longer pushrod onto the short side of the cylinder allowing the seal behind the piston to travel behind the fluid feed passage. Had to pull the axle and drum/hub again but was able to clean everything up and get it right.

I also robbed the good wheels and tires off my 89 to use on this truck. I'll install the polished aluminum wheels on it after I get some longer wheel studs, for now it's just got 4 of the 20s and dry rotted tires from the dump truck on it as rollers.

Next on my list is a couple new coolant hoses, some carb fiddling, get the wheels and tires on, then a test drive to see how the brakes work!

[Bigdually]

Swapped out the leaky coolant bypass hoses for new ones, reattached the choke to idle ramp linkage on the carb so the truck will idle right, and put on the wheels and tires today. I also liberated the bumper from its redneck extension pieces.

Took it on a very brief test run up and down the driveway and it seems to have great brakes! I want to bleed the rears again and maybe see if the shoes need adjusted out just a hair more just for my peace of mind, but all in all a success! Now I have the chore of chasing wiring and making all the lights work so I can get it in for state inspection.

[Bigdually]

Some progress on lighting. All the parking and marker lights are functional after some tinkering and bulb replacing. I dug out a spare set of cablight lenses I've had stored for a few years and replaced the crumbling original ones. I have 3 out of 4 turn signals functioning, just missing the left rear. No power on the wire feeding it, have to track that down. Still to make work are headlights, brake lights, and back up lamps. I know there are some fuses blown, I picked up an assortment of glass fuses and will begin digging into that next time.

[Palf70Step]

Your making oood progress. Very nice looking truck.

[Bigdually]

Originally Posted by Palf70Step

Your making oood progress. Very nice looking truck.

Thanks! I'm hoping I can slowly make it look better after I get it in service. This truck is going to be function over form for the most part though, it will be a working truck.

I quickly realized with the rat's nest of scotchlok connectors and twisted together wires taped together that I found at the rear and under the bed of the truck that I am going to have to wire everything from the rear of the cab back new. Fortunately it's not a lot, and I figured since I'm running new wires why not just use all new lights? Everything will be LED. I'm retaining all stock lighting up front, it works and the incandescent bulbs up there will keep my turn signals working without hyper flashing.

Also received a package with new H4 headlights with glass housings. These are a Toyota OEM part and are widely considered the best 7" round headlight for the money, which is about $25 for the pair with a relay harness and bag of zip ties included.

Now I just need time to get everything installed and working.

[Bigdually]

Little bits of progress over lots of evenings have added up. I have all the lighting and electronics on the truck functional except the horn. Had to get into the turn signal switch to get the signals working plus swap steering wheels to one that wasnt cracked. I think I messed up and left a piece out when swapping steering wheels so that should be easy to fix.

The wiring from the back of the cab rearward was AWFUL, so I replaced and rewired everything from there back with new wiring and LEDs. I'm happy with how it turned out. Also installed new flat panel mirrors and convex mirrors that Dad picked up for it.

I drained the fuel from the gas tank as it was old and pretty varnished. Also changed the fuel filter element. New, fresh fuel in the tank and it fires up and runs pretty well, idles nice and smooth once it's warmed up. I drove it down the road for the first time today to the gas station and it drives and runs pretty well.

I need a state inspection sticker and it'll be ready to go. Also have to swap in and wire up my tach cluster I bought for it, but that will be a project for another day.

[Bigdually]

Fiddled with some of the components under the steering wheel and tightened the mounting/ground bolt for the horn and that's working. Drove it over to a local shop and got a state inspection, it's fully road legal for the next two years now.

Once I got back home I tuned on the carb a little, got it idling much more smoothly and it went from pulling 16" of vacuum to about 20" on my gauge.

Timing is set at 17°. To me that seems high, and it does knock ever so slightly right on first fire up when warm. Next time I have it running I think I'll back it down a hair just until it doesn't do that. Total timing was about 34° which to me seems right, so I hate to back off too much more. The distributor has mechanical advance only, no vacuum advance mechanism.

[Bigdually]

Made some more headway over the last 2 weeks. Stuck on new mudflaps that match, changed the transmission gear oil, greased all the dump mechanism pivots, reinstalled the bed sides and headache panel, temporarily reinstalled the old wooden sideboards, and set dwell, timing, and carb. Topped it off with an oil change. I also removed the fifth wheel plate and pin that had been welded to the bed floor.

She's a little smokey still, I'm hoping her maiden voyage Saturday about 25 miles away will bring some stuck rings around. I have to take it to town for a spring cleanup day around the property at my church where there's quite a bit of shrub and tree trimmings and a bit of wood debris to haul away.

I'm pretty happy with how it goes down the road about a mile and back, so the town trip should be a good run to see how it's going to do. There are two big hills to pull on the way to see how it does under load. Hoping for no major breakdowns!

[yuccales]

That's a great truck!

[Bigdually]

Originally Posted by yuccales

That's a great truck!

Thanks! I think its pretty decent for an old rig to do occasional light hauling. The more I mess with it the more I like it.



Today's trip to town and back (50 miles round trip) was a great success! The truck ran and performed great! 45 mph is about 2500 rpms in top gear, and 55 mph is about 3000 rpms. I wasn't loaded heavy at all, the lowest speed I saw on either of the two big hills was 45 mph, and that was in high range 4th gear. I'm sure hauling stone or dirt will be a different story but I'm very pleased with how the old smallblock handles moving the truck.

I need a load of stone for my driveway, I'm looking forward to seeing how it handles its first heavy load.

[Bigdually]

I thought these pics I just found were neat. I Googled the number on the tailgate of the truck and it turned up a Facebook page of a guy about an hour away who hauls gravel. Went back through his pictures and found evidence of him using it in his business and having it looking pretty nice!