trreed

I've been messing with this stupid fass for so long i'm compiling all the steps and am going to do all of them the first time. Hopefully this will be the end of it

Looks like the end of a helicoil?

Now that's interesting. Did you notice an increase in pressure after doing that @Dieselfuture?

My fass ball looks an awful lot like yours does, and I was also noticing spikes in pressure at higher RPM.. So the new spring and ball are now on their way (along with some new hose for good measure) and hopefully that'll fix some of these issues. I'm sure glad someone else has had these issues!

Honestly, with all the issues I've had with keeping consistent pressure, I've thought about removing the ball and spring completely and putting an adjustable regulator in the return line..

I'm getting ready to do this retrofit this weekend. and I'm still toying with color combos. I'm pretty set on satin black for the housings, but to paint the shrouds or leave them chrome.... hard to match black to a blue truck

I'm glad someone caught the hidden question! It felt pretty dumb to ask "does the airdog spring fit in a fass?" Maybe I've been spending too much time in the Facebook groups reading "how much tire can I fit with no lift"..... @notlimah did you stretch the spring out at all to up the pressure or just run it as it? As for the Viton ball, that is a good idea. My original one definitely has scoring from the spring on it. Hopefully this combo will stop my fluctuations in the FP gauge

Had a question. A while back, someone was talking about return springs from Vulcan (I think it was @dripley?) and ordering the 17 psi return spring. I don't see any spring labeled FASS on their website, does anyone know if they stopped carrying the FASS springs? Or is there a hidden spring I'm missing on the site?

Good news! I replaced the water separator today, and the new filter eliminated 97% of my cavitation issues. So guess I got a bad filter last time.

Sounds like we're both gonna be having fun with fuel today.

So my draw straw is about 1/8" off the bottom of the basket, so the cavitation issues caused by foaming shouldn't be an issue. I'm thinking its either the water separator filter (which I'll be replacing tomorrow) or the ball and spring, and i've already messed with that. Who knows though.

Half of it anyways!

@JAG1 interesting to hear that two other trucks had the same issues I'm having.... @notlimah I will see what I can do, but I am currently located in Sterling, CO (read: flat) so the opportunity might not present itself

Finally got around to working on my sending unit and cavitation issues. The issue did not show itself, and the hoses looked perfectly fine, so FASS will be getting a call about the issue.... But, I did get my 1/2" return fitting installed, so there's now worry there. Also, I set a personal best for fuel mileage. I had an hour commute each way for the past two weeks, and managed to get 18.55 mpg, sitting in stop and go traffic while running the A/C. I'm pretty happy with that! Anyways, more on the cavitation when I get the time to call FASS.

@WiscoRedkneck What'd you do to that poor 4L60?? Did you try the old timer "Self-Alignment" trick of going as fast as you can in reverse and then quickly shifting all the way to 1st? Heard that's the best way to realign all the sun gears.....

Unfortunately, I won't have time to dig into it until this weekend. And here's to hoping the issue will present itself quickly. Though I know it won't. ☹️

That's basically true, @kzimmer. It's only a $100 fine, which I personally think is hilariously low for how much hype there was for this bill to pass

Interesting. I didn't think about that. Though this issue happens at any fuel level. I'm starting to wonder if I poked a tiny hole in the supply line the last time I had the bed raised, since it's gotta be sucking air from somewhere, and the air separator filter is doing its job well

The return from the Fass is plumbed into the old stock supply line, so the return drops right into where that "H" with the check valve was in the stock setup, so directly above the basket.

@notlimah you are correct now that I think about it. It is the fitting holding the bulkhead to the top of the sending unit that is loose. The suction tube is a Drawstraw V from Vulcan, so there is a hose clamp on the suction tube in the tank, which should be tight. The Fass is still getting air in it somehow... Either way the sending unit has to come out to fix the bulkhead, which leaks diesel down the side of my tank...... So hopefully the air leak will present itself then.

So this isn't necessarily an upgrade post, but more of a "This is why you don't let your Duramax friends work on your truck" post. Long story short, my Fass 150 (10 months old) has developed a cavitation issue. You can hear the pump sucking air when it was running, and every now and then it would lose its prime. So today, I adjusted the return spring (15psi to 20 at idle!), and out of curiosity I started poking around the top of the sending unit. Lo and behold, the bulkhead of the drawstraw is loose (which the aforementioned Duramax owner insisted on tightening) and is allowing air into the system. Dammit Jimmy. So, a repair date has been put on my calendar, and at the same time I will look at the return system itself, and put a second bulkhead fitting to allow for a 1/2" port of return instead of the 3/8" port it is currently returning in. And no Duramax owners will be there to "help" lol.

^ lol he'll never dream of doing that.

Story time @TFaoro

More like his trashed p pump..... Thought the whole point of the swap was to not have to buy another injection pump? Though @jlbayes, I am known as Mini Tyler for maybe following his upgrade path...

So the instructions I've followed in he past to see the voltage read by the APPS is to put a paper clip in pin #3 (green wire) and that will allow you to read the real time voltage, which the adjuster screw will change as you turn it. .65 volts at idle sounds right to me, but that is for a Timbo APPS, which may have a different idle voltage from an OEM one