THE THIRD YEAR

Yup, three years as of February 2014. Since being so late with my last post, I thought I'd try to catch up on what's happened since our return from California in January. The Bus sat exactly where I parked it on arrival for almost two months. 

I plugged her in and left the mini-splits set as low as I could (60 degrees F). Amazingly with temperatures dipping into single digits, the system could still extract heat from the ambient temperatures. I thought I had enough heat in the utility bay to prevent freezing, but after a couple of below zero nights, one of the plastic PEX manifolds burst. I also had the refrigerator to repair and I decided to send the Victron back for a go-over since it was still under warranty. I was convinced the inverter was the cause of the refrigerator cable fire. 

So, my first project in the Spring was to pull the inverter and send it in for testing. The good news was that there was nothing wrong with it. The bad news was there was nothing wrong with it. I'm still unsure of the cause of the meltdown. I got the inverter back and re-installed it with a few "better ideas" added. I can't find any abnormalities in the system. I hate it when that happens!

Donor accelerator pedal

Next - replacing the cable throttle with an air throttle. Although I pulled, cleaned, and lubed the cable when started the project, it has gotten more sluggish over time. The decision was made easier as the parts bus had an air throttle. When I drove the parts bus home, the throttle response was so much better, that I moved it to the top of the To-Do List.

The first step was to remove the system from the parts bus. That was pretty straight forward - unbolt the accelerator pedal assembly up front and the piston assembly in back on the governor. The pedal assembly is a proportional air valve with three air lines. A supply line from the front air tank, a distribution line to the actuator piston on the governor, and a vent line to depressurize the air valve. The picture shows the valve with the pedal removed.

The old pedal had to be cut out from the brake/accelerator assembly and replaced with the air pedal mechanism. It looks easy. Took about two hours. 

New pedal

Old accelerator pedal

Next, the old cable throttle was removed. Then the air throttle had to be modified because the governor on the Bus was different than the donor's. The mounting plate had to be modified by adding an extension plate and the pivot return arm flipped to make it work on my governor.

New air throttle

Old cable throttle

I ran 45' of 3/8" air hose from the pedal assembly to the throttle piston, aired up the system with the shop compressor, fired up the Detroit, and volia! Great throttle response, and a drastic improvement in overall drivability. I don't use the clutch once rolling, so quicker shifts are possible since the engine revs drop quicker with the air throttle.

STILL TOO HOT

Driving in the mountains last winter pushed the cooling system to the edge. We had to pull over a few times when the temp started climbing past 190F at 80F ambient. With electric fans, it only took a few minutes to bring the temp back to 180F, but that's not going to hack it at 95+F. I didn't want to go back to the stock the radiator and crank driven fan which failed twice in the past. My decision was to install an additional, independent oil cooling system to take some of the load off the water cooling system. I haven't seen this done before, so it's pretty experimental. I installed two 18"x24" Hayden oil coolers in series - tucked into the space behind the rear electrical panel which is pretty much empty since I gutted all the original wiring.

 The coolers are hung with rubber hangers stacked one behind the other. A remote, 12v electric, gear driven oil pump moves 5 gal. per minute from the bottom of the oil pan, through the oil coolers and returns the oil via a fitting in the block below the oil fill. I cut a hole in the bay door and also in the aluminum panel separating the compartment from the area behind where the coolers are

located. I mounted a Flexalite fan to push air through the coolers. I've done a short run, but not under conditions that would put the system to the test.

Next: The Shop