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Lonestar10 · 01-27-2019, **(Subject: Air in DAVCO )**

I see about 1 tiny bubble to 2 per second drift to top of fuel from bottom of davco and usualy has a small bubble ring around my filter. is this severe/normal or probably needing to reseal all the international PTC fittings?

Waterloo · 01-27-2019, **(Subject: Air in DAVCO )**

More than likely a pinched o ring... But, if just a bubble or two, you are probably OK. You will get some bubbles, how is the truck starting? That is when you have issues, the truck will hard start or not start at all.

If you don't have a Davco wrench, it is worth the few bucks they cost to get one and leave it in the truck.

This is for the 382 Davco, most popular model/size wrench.

https://amzn.to/2GMMsTO

Moose · 01-27-2019, **(Subject: Air in DAVCO )**

I just did one of these on an ISM in a 9400. Just know it will not get any better. They can work through some air but as restriction increases so will the air intrusion. It didn't become a non-running issue until the CELECT pump got weak and couldn't maintain rail PSI over the bubbles anymore. It didn't make sense to this guy to spend the money on a 14 year old housing, so instead we took the Davco off, replaced all the plastic PTC lines with aeroquip hose, eliminated the coolant heater lines (we are way down south) and installed a spin on head with a FS1000. This will change to a FS1242B or something similar with a bowl next service interval so he can see any water or trash visually as this one doesn't have a WIF sensor.

Volvo8873 · 01-27-2019, **(Subject: Air in DAVCO )**

(01-27-2019 )Lonestar10 Wrote: I see about 1 tiny bubble to 2 per second drift to top of fuel from bottom of davco and usualy has a small bubble ring around my filter. is this severe/normal or probably needing to reseal all the international PTC fittings?

Depends on what number fuel grade you put in and how cold it is also. I get more bubbles in both trucks with Davco 382’s when it is cold (like I am sitting in -10 weather this morning) and I use Number 2 during the winter unless it gets -15 -25 range then I get nervous and throw in some Number 1.

Like Waterloo said maybe you have pinch O-rings also? Is the truck running rough? I say if it is not then not to worry about it.

Waterloo · 01-27-2019, **(Subject: Air in DAVCO )**

I get teeny tiny bubbles in my Davco, you have the fuel running through there under pressure, so a bit of cavitation I would "assume" is normal. I know when the Davco o-ring is pinched, the truck normally will not start, or take a while. If you are not having any issues, I would again say this is normal.

Chamberpains · 01-27-2019, **(Subject: Air in DAVCO )**

Davco states on their website that champagne size bubbles are fine. it's from the turbulence in the tank from the fuel returning and being sucked right back through.

Anything bigger than champagne size bubbles and I would personally give it a good thorough look over. Including the drain valve on the bottom, reseal the pipe threads for the inlet and outlet, replace all the o-rings, and check the anti drain back ball in the inlet line. For a couple hundred bucks you can put a whole new unit on it if it's old and needs replaced.

Waterloo · 01-27-2019, **(Subject: Air in DAVCO )**

And to add, I was surprised, mildly surprised, at all of the crap that the bottom of the Davco unit accumulates. It does collect quite a bit of crap. Would be a good idea to drain completely and clean out every now and then.

Lonestar10 · 01-05-2020, **(Subject: Air in DAVCO )**

Finally got around to the videos.
20,000 mile filter
https://youtu.be/K_ph4B1eEyg

New filter 5min later
https://youtu.be/K9WOyz5Uwr8

Evotrucker · 01-05-2020, **(Subject: Air in DAVCO )**

I have this same issue with mine, small air bubbles like champagne bubbles are fine... tho in my opinion yours are champagne size but some come out bigger then others.

When i changed the oil and filters on my truck recently, i replaced the plastic housing cuz the old one had a yellow hue to it so it made it difficult to see threw it lol. after reading online for a while i think its the air bubbles that get sucked in and out of the tanks that's causing mine to have bubbles like your's.

I found a system that treats that issue with air in the fuel lines, airdog or something along the lines. It's supposed to help the lifespan of the injectors by taking out the air bubbles or air period in the fuel lines and system, the price i saw was $600 or a lil more but anyways, i hope its just air bubbles and nothing else.