Engine/Transmission (1998.5 - 2002) Air Dog vs F.A.S.S.

[jzenk]

Need some opinions. Pressure from the LP is slowly dropping. I'm interested in one of the aftermarket pumps. What are your thoughts on the Air Dog & FASS systems. How do they differ? What's good or bad about either of them? I'll keep the truck a long time so don't really care that much about cost... just want to do it right the first time. It's a '01 ETH 90,000mi No fuel enhancements YET. Thanks for your help, Jim :-{}

 

[HeavyHauler]

Here's what you want. Do a search on AirDog and you will have all the reading you need.



That post above has some great information posted by Roger rodbolt - really nice guy.



The thing that sold me on the AirDog was the fact that you can leave your truck idling while fueling but can't with the FASS. I know that seems funny but I think both systems would be great. The AirDog is smaller and much more refined than the FASS and is actually the "original" design of a fuel preporator. The FASS is supposed to be copied from the orignial 135A which is a full size AirDog for a big truck.



I haven't installed mine yet but I'm looking forward to it.



Good luck.

 

[tshunt]

I went with the F. A. S. S. Main reason was cost. I can use the 150. 00 bucks for something else. Both are based on the same design. I've only had it installed for a week now. Quality product, install was fairly easy. Engine is allot smoother is all I can really say for sure so far. I am happy. I held off on the purchase for a long time waiting for the airdog to debut. I even had the airdog on order as soon as they were available. I cancelled my order after calling to check the status after 4 weeks and the only answer I could get was "it's probably going to be awhile still" from the rude lady that would hang up before you could finish talking. Sorry Charlie!!!

 

[woodsrat]

I heard the DPP has made changes to the return on the FASS now and it is possible to refuel with the truck running. Regardless of having to shut my truck down to fuel i love the FASS. I have not had a fueling issue since it has been installed. And like the last post said you dont get a rude girl if you have a question about the FASS, call and ask for brad and he still takes the time to talk to you personally.

 

[Rockcrusher]

Glad to find this post. have been thinking about gettin FASS and then Air Dig comes up. Glad to hear the reports, sounds like FASS is the way to go.

 

[DHayden]

When I inquired about the Airdog, Charles (the owner) answered all the questions I had directly. In fact he answered more questions than what I had prepared and being rushed wasnt even an issue. To each his own I guess

 

[Caveman]

Seems like all the FASS owners have issues. I haven't had an issue with the AirDog. The fitings and machining seem far superior to the FASS. Kinda the difference between a do it yourself kit and the real thing. I wouldn't go back to a FASS. Sticking to my Airdog.

 

[1FSTDSL]

Seems like all the FASS owners have issues.

 

[Caveman]

OK, so why the rolling eyes smiey?



I'm always open to good information.

 

[1FSTDSL]

All FASS owners have issues? Mine has been flawless, couldn't be happier. Oo.

 

[KVaughn]

https://www.turbodieselregister.com/forums/showthread.php?t=119200



Rodger Rodbolt explains it better than any thread or post I have seen so far. Just the fact that you have to remember to shut your truck off to fuel with the FASS steers me towards the Airdog. Also, less parts and gaskets would seem to provide a more reliable product. Now just need to convince my wife that a stock lift pump really costs $700.

 

[GKinney]

Fass

I've had real good luck with my FASS. Had it almost a year now even through the cold winter with now problems or gel ups. At first I was having problems with the pump picking up prime when the tank was about 1/2 full, replaced stock suction with 1/2 pipe, works great. I would suggest that mod to any type of high volume pump!! Stock tank modules are junk. Don't really care about shutting off the engine to fuel, I always do anyway so it doesn't suck up any dirt stirred up in the tank. Would like to see an Air Dog installed, looks sweet. Go with the smallest micron filter you can get though.

 

[Wiredawg]

Refueling Running w/ FASS Easy...

All I did was got to hardware store, get 6" long pipe (can't remember diameter), 1/8 NPT thread 3/8" (I think) brass push on fitting and a couple of hose clamps. I drilled/tapped pipe, screwed on the fitting, cut out 2" of fuel filler hose and installed/clamped pipe into fuel filler hose. I then installed return hose from FASS. I don't ever refuel w/ engine running, but I can if I want to.



Sorry I don't remember dimensions: I did this when I installed my FASS almost a year ago.



I like my FASS and have a 2d one to install on my wife's 03 in a couple of months.



Thanks, Wiredawg

 

[tshunt]

Just the fact that you have to remember to shut your truck off to fuel with the FASS steers me towards the Airdog

Yea, I often can't remember to shut-off my truck too. It's so quiet and it's such a good idea to fuel your truck with it running

 

[KVaughn]

Not that I always fuel the truck with it running; however, it is nice when you have passengers and its -10 outside and you can leave it running with the heat on. Sounds like the FASS just has some bs limitations that the air dog doesn't. Thanks for the reply anyway smartass.

 

[tshunt]

Sorry, your original post just sounded silly. Buy what you want but don't make such weak arguments about why one is better than the other. You own neither, so you have zero experience or common sense obviously.

 

[Mad Bomber]

Not that I always fuel the truck with it running; however, it is nice when you have passengers and its -10 outside and you can leave it running with the heat on. Sounds like the FASS just has some bs limitations that the air dog doesn't. Thanks for the reply anyway smartass.

If it's installed right this is NO issue at all. I can open it and fuel it running. Just have to cut the return hose off in the right spot. Mine is real close to the tank and long ways from the fill side.

 

[KVaughn]

Since my LP failed on Friday and I must make a decision on a fix this week, I have two more questions:

1. How does the RASP system compare to the Air Dog and FASS? Based on the small amount of research I have done, the RASP is a belt driven pump that does not purge the air like the AD or FASS. Is it worth the $629 or would I be better off spending that cash on the fuel / air separator type of system?



2. Both the FASS and Air Dog claim to make engine run smoother and quieter. How much different is it really? Do you still have to turn the truck off at the drive thru? Obviously it doesn't bring it down to the HPCR noise levels but is it really that noticable?

 

[Edward]

Since my LP failed on Friday and I must make a decision on a fix this week, I have two more questions:

1. How does the RASP system compare to the Air Dog and FASS? Based on the small amount of research I have done, the RASP is a belt driven pump that does not purge the air like the AD or FASS. Is it worth the $629 or would I be better off spending that cash on the fuel / air separator type of system?

KV

With the Rasp you still have to keep the factory POS fueling system or it won't work.



Edward

 

[kscheffler]

Plus the RASP does not remove any dissolved air. Seem like if you are going to go through with all this effort that you might as well also remove any air in the fuel which is another issue with CTD.