Taking the plunge. My journey as an O/O.

Update.

Fuel economy is definitely down about 10%.

I understand this is because the cylinders take some time to seal up after a rebuild.

In top gear, the fuel economy used to never go below 3.5 MPH as long as the engine wasn't struggling. Today, that minimum is 3.2 MPH.

Overall fuel economy used to be about 6.8 MPH. Today, I am averaging 6.1 coming out of Texas on I-30, which is fairly flat. I am into AR now, and have been seeing some hills, but my economy overall is definitely still down.

 

Your fuel economy should slowly improve as things break in, but that's horrific. I'm trying to figure out why it was so bad before all this. If your mpg is 6.8 with that truck, that is the very first thing you should be focused on. Something is wrong.

 

Well, there is one problem right off. It's an opti-idle truck, so when it needs to turn on to cool the sleeper, it cranks the engine. That is much less efficient than an APU.

Second, it is a manual transmission, not an automatic, so it doesn't cheat and take the truck out of gear when hill coasting, like automatics will.

The truck never got more than 7 MPG over any significant distance while I drove it as a company truck, and Crete never gave me any issues about it.

 

Forget about the manual vs. auto. Manual is just as good if not better depending on driver. It's true.
I see your point with high idle time though. That truck hauling dry van should be in the low to mid 8s unless your on a dedicated bottled water account in the Rockies.
Idk. Just something to consider as if you don't have enough. Lol.
An aero truck with a DD15 or series 60 for that matter should not be in the 6s hauling dry van freight.
Not criticism, but I would be looking for improvement there considering the amount of miles you turn.

 

I am not hauling dry van. I am hauling reefer on a major account, and rarely get a load much less than 40k in the box. A large part of my loads have a lot of Appalachian Mountain miles.

 

Update.

During PTI this AM, I discovered a small coolant puddle under the truck, a few inches in diameter. Coolant level in the reservoir was down a bit. I pulled forward a couple feet, cranked the engine, watched for a minute, and saw a drop fall. Cannot see where it is coming from.

There is a Freigliner dealership a few miles away. I will be driving over there this morning and hoping this is something easily fixable.

 

Well, the best thing you have going for you now, is the fact that Freightliner did the work, and they’re everywhere, if there’s a problem.You probably have a loose hose clamp

 

I wound not have been too surprised if there were a few little hiccups like that after being so far apart. If the cylinders are all new it will take some time for those to break in also. I don’t think your MPG is that far out of line if you are on an account that loads heavy and are including the idle time. 7 if lucky maybe.

 

Update.

Sikeston, MO Freightliner does not have 40 trucks in line in front of me. They are going to get someone on it in a few minutes to pressure test the coolant system and find the leak.

 

I find external coolant leaks easier to just diagnose and fix myself. You can typically do it in less time than it takes for them to even check the unit in and get it into a bay. You can also feel better knowing that you fixed it, rather than having to take it back again or end up doing it yourself anyway if they didn't correctly repair it.

There are usually only a few coolant lines in hard to reach places. First I'd give the hose clamps a quarter turn to see if it fixes it, and another turn if it doesn't. Then I'd replace the hose and clamp, or cut the hose if you have excess and replace the clamp. If there's still a leak, I would replace the fitting. You can get coolant pretty much anywhere, most hoses from auto supply shops, and specialized hoses and fittings from the dealership. Make sure your coolant filter is tight. Check the shutoff valve and housing before the filter if you have one.

I've tried plastic welding and using plastic epoxies for the expansion tank with limited success, but only as temporary fixes.