THERMO KING Tri-Pak APU

If yo alt goes out take it off and take it to c&s electric on mableton pkwy. Had them repair mine with better parts and it works great.

 

I run the maintenance side of a mid size trucking company in Roanoke, Al. and we looked at the plus and minuses of the APU for our fleet. the initial reason was for increasing fuel mileage by eliminating unneeded idle of a 13 or 15 liter engine just to heat/ cool the driver. while there have been savings, albeit some what less than expected , this wasn't our only reason to pursue the APU. We run a mostly Volvo fleet and we were replacing EGR valves annually if not sooner caused by hi idling related failures. The truck engine is "tuned" to be its most efficient at highway speeds and when Idling for extended periods of time build up excessive amounts of carbon which causes EGR valves to stick open/ partially hung, or not fully closed. At a cost of nearly $2000 to replace both, pipes, clamps, shop time and down time, not to mention lower fuel mileage it doesn't take much time to make a dent in the initial investment. Also when you idle the truck engine all night it doesn't cycle on/off as needed, so if you run the big engine 10 hours we were burning about 8.8 gallons vs. less than 1 for the APU, BUT the APU cycles on and off as needed and we are seeing maybe 6.5-7 ACTUAL hours of running time over 10 hours. with a real fuel burn of about .6 gallons per night. Now do the math,

8.8 gal X $3.80/gal= $33.44 per day
$33.44 X 5 days= 167.20 per 5 day week
$167.20 X 4.3 weeks/ month =$718.96 per month
$718.96 X 12 months =$8627.52 per year in POTENTIAL Idle fuel savings

I say potential because on nice cool evenings my drivers may open windows or not run unit as much, only to keep batteries charged for refrigerator and fan blowing in bunk.

along with just 1 less EGR replacement in a 3 year cycle my projected savings are ($8627.52 X 3 years= $25,882.56 PLUS $2000.00 EGR service =$27,882.56!!!!!) less the initial cost of unit, ours were $10,380.00 installed with options leaves a savings of $17,502.52 for any service required. Driver turnover has decreased 50% in trucks with APU's and some of these have 900K+ but they are well maintained and washed every week.
Just some food for thought, look at the whole picture, take off the blinders and look for other less obvious benefits. we went from 0 APU's to 90% in 12 months by retrofitting 33 trucks and buying 14 more that had units already. we still don't use them on local trucks that only idle @ 8% anyway.

 

Thanks for the informative post. What options did you choose and why did you choose them? Any regrets as far as "If we had to do it over again we would have..."?

 

You can avoid glow plug and glow plug screen replacement :
-during the summer (worm weather) run the bunk heater for at lest 30 min once a month.
- 3-4 times a year run the bunk heater on kerosene. no, it will not burn anything! actually, i know guys running these units always on kerosene
- avoid running the unit at maximum setting temperature. it's allowed to run at maximum for 2 hours maximum.
- what is destroying these bunk heaters is the fuel. take care where you are fueling your truck. some fuel additives are doing worse then good to bunk heater.
- once a year check the filter of the fuel pump, fuel lines. leaks are destroying these units, too.
- check and clean the wires, in special the grounding from time to time. avoid running the unit while you use big consumers, microwave, beams, etc.

For the glow plug replacement the part comes with a a wrench for the job. ask the dealer for it. the wires of the plug are very "sensitive" handle with care, avoid stretching the wires

 

Last winter I had to replace the burner box/chamber on mine, it had lasted 7 winters. The guys at ThermoKing were amazed it had lasted that long, they said they often replace them at 2 to 3 years old.

This past week I had to replace the blower motor, into the 8th winter I spun a bearing, a month before my new tractor arrives.

 

Looks reasonable to me. 300 $ divided by 7 is still a good number for me, comparing with 10 hours of idling by night.

 

I bought my tripac four years ago for 9800 installed and have never had one break down. It saves me about 900 gallons of fuel per year over the years before I put it on. I'm out three or four nights a week. You have to sleep in the truck more then two nights a week to make it pay for it self. But the real reason I got it is idling is the worst thing you can do to a diesel engine. All you are doing is loading it up rings with carbon and getting unburn fuel in the oil. Engine life is the reason I bought mine.

 

The tri-pacs last along time with good maintenance. This one i have is on 3rd trk now transferred. It has 27,318 hrs and still running, just normal wear and tear items. A/c comp,alt, coolant pump and hoses and a few sets of glow plugs and 500 hr services. T/k says a 1000 but oil and filters are cheap insurance.

 

that what TK dealer told me is these little diesel motors will last over 20K hours with very few break downs. It is alternator or A/C compressor might go bad but at those hours everything got a wear point. Have two other O/O I know very well they both have tripacs over 10K hours on there tripac's with no repairs at all. Mine is at 4K hours I use it about 1K hours a year and it is the best money I have ever spend and would never have another truck with out one.

 

They are saying the new Evolution model can go 1500 hours between PMs.

I'm at about 14,500 hours on mine. When trying to calculate the savings, the mind blower is that with the TriPac the actual number of hours I would have idled would have been much higher, since the unit is only occasionally running when I am heating the cab (to heat the engine block or charge the batteries) while other APU models on the market must run all the time to make heat.