Eric

Yes the extra tanks where to make sure there was enough reserve air for multiple brake applications and in the case of vehicles which were used off road such as logging trucks they where common to have more air tanks dedicated to the suspension systems one per axle to help with the extra air usage by the ride control valves over uneven terrain the alternative to this was to use ride height valves with a damper to slow their reaction time to changing ride height. Remember that air suspension was considered an accessory and would only receive air after the brake air tanks where filled above 70 psi requiring separate tanks to maintain the separation . On trailers such as a low boy it was common to have dump valves to lower the deck for loading ,these systems often used larger or more air tanks with relay valves and larger air lines to the air bags to help speed the recovery of ride height when loading was complete as this operation would use more air volume than could be supplied from the tractors air compressor quickly .

Gee Gary thars a lot of super singles!

Brian On your air tanks they would have been set up with two air tanks the first one would be a tank with a centre separator effectively making it two tanks in one. In this center divider wall there would be a check valve the air from the compressor would be pumped into this first tank was known as the wet tank where the moisture in the air would collect as that compressed air cooled. Each tank would have a mechanical drain cock to dump any water collected . The wet tank would not have any air lines running away from it as it was only used as a wet tank the other half of that tank was referred to as the primary tank this tank would be used to operate half of the brake system we'll say the front brakes so there would be an air line running up front to the treadle valve. From the primary tank there would also be an air line which ran from the primary tank to the secondary tank this air line would have a spring loaded check valve known as a priority valve it would allow the primary tank to pressurize to 70 psi before it would allow any air into the secondary tank this was done to separate the two brake systems front and rear so if an air line where to blow or be severed the other tank would still have air to operate it's related brake system. The secondary tank was used to operate the rear brakes and as such had an air line running to the treadle valve as well. From the treadle valve there would be at least two air lines one running to the front brakes and one running to the rear brakes . The front brake supply would have a QR ( quick release ) valve in line to aid in dumping air on brake release to speed up the brake release. The rear brakes may have been the same way or which was more likely the case would have had a relay valve close to the rear axle/s this valve was sometimes mounted right on the secondary air tank next to the axle , the object here was to feed enough air supply to the rear brakes to run as many brakes as there are axles brakes at a faster rate. This secondary air supply to the treadle valve would also be used to supply air to the yellow parking brake valve on the dash this valve was pushed in to release the parking/ spring operated brakes and was setup so that in the event of air pressure lose the ( below 60 psi the valve would pop out and dump the air off the parking /spring brake chambers which would allow the springs brake chambers to apply the rear brakes.making the system fool proof. This valve as mentioned would be either feed from the secondary tank directly ( screwed into the air tank or by a larger air line this relay valve would also have an air line which is run from the treadle valve as a signal line to operate the relay valve the relay valve would also have a QR valve built into it to speed brake release for the rear brakes as well. The only other line connected to the secondary tank would be for accessories like air suspension,air wiper motors,air horns etc this air supply would be connected to another priority valve screwed into the air tank which would maintain 60 psi in the secondary tank in the event of a major air leak in any of the accessories. If the vehicle had air suspension it would likely have another air tank feed by this supply. There would also be a smaller air line from each tank one primary and one secondary these would run directly to the dash to operated either a dual all in one air gauge or two air gauges on the dash. Hope this helps Eric

Brian Sorry I didnt get back to you earlier we've been on the road . The cable you show on top of the governor is a mechanical tachometer drive cable very much like a speedometer drive cable.

Brian the governor was a strictly mechanical device with mechanical linkage to the carburetor some may have had an electrical solenoid operated control to step up idle RPM For PTO operations In the picture of the back of that engine the electrical sending units you see below the governor are oil pressure sending Units for the oil pressure gauge, maybe an idiot light and possibly a kisor system which would shut down engine in the event of a No oil pressure or over heat condition ( these systems used to be common before electronic engines.) For electrical to the rear of the truck there may have been work lights at the rear of the truck as well as things like a two speed rear end or differential lock which could be electrical solenoid operated. Hope this helps Eric

All it's missing is some muddy foot prints on the deck plate.

Those mud flaps look like they've been driving through cow pies. Great job I've used hobby lobby craft wire inserted into the air hose to allow you to bent and shape it the way you want with that said yours look great

The 4070A kit was also my first kit back in 1974 and I liked it so much back then that I'll probably build it again sometime. With an o/o the colour choices are endless as usually an o/o would custom order the truck they wanted with their choice of engine , transmission,rear end ratios, fuel tanks ,etc With Peter built their frames would have been a satin black colour but you could order you frame in any colour to match your body colour or to contrast it if you liked and I'm sure Kenworth would do the same for a price. Most trucks if not spec ordered in a specific colour would come black usually a satin or matte black I personally like my model frames in a flat black as the satin looks just a bit too shiny for my liking. But remember this is your build make it any way you like and enjoy your self. Ps: if you prime the body with black primer then paint with that bright yellow you might get close to the rider colours on the box

Brian if your just looking to dull the chrome down to look more like aluminum try spraying some mate clear coat on them it takes them down very nicely.

Those rear fenders look sweet! Keep up the good work

Thanks Johnny I tried to create everything but the stink. Lol

Here is a picture of two of the refuse truck being suspend towed as promised

Looks great so far On the fuel tank you'll see three fittings close to the frame on top of the tank that is where the fuel pickup and returns would have gone the larger circle out towards the outside of the tank was just the fuel sending units for the gas gauge and would have had two wires connected to ita ground wire under one of the out circle retaining bolts and a signal wire to the center of the sending units. I didn't get into all the air lines and wiring as you have .but as I spent the last five years of my career as a heavy equipment mechanic I did try to connect as many hydraulic lines as I could . The kit has almost enough hydraulic line to do everything except the over head line front to rear which I did with craft wire ( If l had it to do again I'd have used solder for those instead. I also drilled the tailgate latches and used craft wire to hide them so the tail gate could be opened. I also added the winch cable and snatch block as shown on old purple As you can see I weathered this one up as a fifty year old heavily used unit ( maybe a bit over done) and will be suspended towing it with my already completed AMT Pete tow truck.

Hi Brian on my build I cut a notch in the top of the ejector wall and built a channel to run the hydraulic lines from the front wall back to the tail gate like the 1:1 unit did From my research and experience there should be three hydraulic lines running from the front to the rear one from the forward valve block to run the tail gate lift cylinders And one pressure line to the packer control valves on the passenger side of the tailgate to operate the rear packer. There should be a return line in that conduit as well making a count of three. It looks to me like the return line running from the forward valve body should have run up and teed into the return line coming from the front and then go through the filter housing on the upper front wall before going back to the tank.( On the kit AMT show the return line from the forward valve body going straight back to the tank. There is a hydraulic circuit diagram in the patent diagrams for the PL 900. The packer hoses should have teed on the upper movable packer section and the run to the passenger side wall where they would connect to the control valving. In the 1:1 packer that hydraulic line conduit was welded or bolted to the roof but on my build I wanted to be able to lift the roof off as you do so I added a cross member at the upper rear of the packer to carry the conduit. I'll try to post some pictures of my build tomorrow. Eric

Hi Brian This is my first post on here so bare with me. After a 43 year career as a truck and coach mechanic I retired and am traveling with my wife in an RV six months of the year . As a kid I built many of the old ertl truck kits but haven't built any in nearly 50 years until recently I'm currently working on my second one The Garwood refuse truck you are working on and found a good link for the detailing of the compactor. Below link https://www.classicrefusetrucks.com/albums/GW/GW18.html Also the picture of old purple on the box cover has an tube video of the actual truck. both of these should help with the detail