APU Issues (Tripac Evolution) - Struggles To Start, but before I panic......

Mike

Well-Known Member
Staff member
APU is now in it's fourth year of service, and when it isn't having problems, it is running just fine.

Here is the issue, and I will notate it in the order it happened.

  • Alternator was out. Called TK in Joplin and they had time to replace it that day. Weather sucked, and I didn't want to work out in the weather, so I had them replace it. They also gave me a price on replacing the top cover that was damaged, and I had that replaced as well. this included a little work such as bending other pieces back in place and riveting the fan assembly back properly. Basically, making it look new again. In the end, all was well. APU ran fine, and looked like it was brand new. Without asking, there was a fuel screen that was removed and cleaned. They pointed the screen out to me showing me how dirty it was and how quick lube places usually never even look at it.
  • Took truck to Dealer to have overhead on engine. This was just a few weeks after alternator replacement on APU. I was taking off for a few days, so when they called me to tell me it was done, I asked them to make sure the APU switch was turned back on, so batteries would be maintained. I get back a few days later and the switch was turned back on, but so was the A/C. Basically, the APU ran for several days straight.
  • Since then, I have ran into issues. 3 times now, the APU has taken a very long time to start. I was alerted to an ENG issue from the controller, in which the engine failed to start. I have been alerted to that again with me in the truck, but I simply had to turn the unit off, and then back on and wait for it to struggle for a long time to finally start (had to let it attempt to start multiple times before it finally started up). Twice since then, I have had issues with it having trouble starting up, taking several minutes to finally run smoothly.
APU will work flawlessly for days. It's almost like there is trash somewhere, or possibly a failing pump. Could be it is simply a fuel filter issue what will be taken care of on my next service. Getting service done in the next couple weeks, hoping that is the problem.
 

mndriver

curmudgeon extraordinare
Supporter
Between the fuel filter and the prefilter, there's a small electric pulse pump.

I've been having nothing but issues with burning that Pump out for some time now. Replace the pump, runs good. Starts having issues, find the pump gets power, but not running. Not sure why.
 

Mike

Well-Known Member
Staff member
Between the fuel filter and the prefilter, there's a small electric pulse pump.
Does it look like a little pancake filter? Not sure if my evolution has that or not, but I seen others having issues with that on the older models.
 

mndriver

curmudgeon extraordinare
Supporter
I don't know why it wouldn't.

It's directly behind the fuel filter for location.
 

Mike

Well-Known Member
Staff member
I don't know why it wouldn't.

It's directly behind the fuel filter for location.
When I take it in for service I will make sure to have all filters replaced and hope my problem goes away.
 

Mike

Well-Known Member
Staff member
Between the fuel filter and the prefilter, there's a small electric pulse pump.

I've been having nothing but issues with burning that Pump out for some time now. Replace the pump, runs good. Starts having issues, find the pump gets power, but not running. Not sure why.
Had this issue periodically since posting this. Actually only a couple times and it has been running fine the past few days.

It was due for its yearly service, I get that done every Spring. Thermo King in Joplin wasn’t swamped so I got it in this morning after getting unloaded and before my pickup at noon today.

Perfect timing, that pump took a dump on me while at the shop.

Got the pump replaced, in and out of there within 90 minutes.

Pump cost wasn’t bad, $141.75.

Ended up getting out the door with the PM service and the pump for under $500.00.

Hoping that was the intermittent issue I had been having.
 

GAnthony

Non-Canadian truck driver
Supporter
Had this issue periodically since posting this. Actually only a couple times and it has been running fine the past few days.

It was due for its yearly service, I get that done every Spring. Thermo King in Joplin wasn’t swamped so I got it in this morning after getting unloaded and before my pickup at noon today.

Perfect timing, that pump took a dump on me while at the shop.

Got the pump replaced, in and out of there within 90 minutes.

Pump cost wasn’t bad, $141.75.

Ended up getting out the door with the PM service and the pump for under $500.00.

Hoping that was the intermittent issue I had been having.
just a question, if you do not mind..did you buy a spare pump while you were there?
 

GAnthony

Non-Canadian truck driver
Supporter
No. If it breaks I’ll just take it back to them.
ok, cuz i was thinking if you are far from a service shop, at least you can do it yourself.
 
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