You just let me solve a problem I have been dealing with for years.  Thank you.  A bad fuel cap has cost me several hundred dollars in repairs to fuel filter replacement. (2008 LMM Duramax towing a 5th Wheel)

I'm a 1st time owner of a 06 lbz  and this is informative. I've Learned alot about fuel rails and suction pumps. You are a professor! Thank you

You said I’m trying to let you guys go and I got sad. I’m over here soaking as much information as I can! Great video

2002 GMC Sierra 2500hd lb7, i learned something new, thank you.

Thank you for the incredible presentation Tony! I’ve been digging through forums and different YouTube videos to better understand my LB7’s fuel system and this is by far the best one explanation. Thanks for sharing this on YouTube!

Really impressed by this video. Looking forward to learning more.

Tony,  thank you so much for an excellent presentation. I have been wanting to add a lift pump to my 2005 GMC Sierra because I've seen lots of videos on you tube explaining the advantages of this. However, I was still hesitant because I didn't know exactly how the entire Duramax fuel system functioned. Thanks to you I now feel confident that adding a lift pump will be beneficial to my Duramax.   Love your channel and keep the great videos coming.

I installed an AirDog lift pump on my LBZ recently, and so far I believe it to be a positive upgrade. It sounds a little different and starts easier, and it revealed an early leak starting in my primer pump that I'm about to take care of before it becomes a bigger problem. Its super easy to bleed the system now as all you do is loosen the bleeder and turn the switch on. I fell like I have better filtration too and may replace the factory filter with an a spin-on adapter for a Donaldson Blue filter in addition to the lift pump filters. I never leave my truck running when fueling. Thanks for posting very useful and knowledgeable information.

THANKS!!!! for not loading this video with stupid ads. I didnt realize the original cap could be the overlooked culprit. I have a customers Duramax. He states it runs for 2 hours then shuts off, then wait for 30 minutes to restart. It also takes several crank revolutions to start. I am changing the full fuel system (hard lines, cooler, filter, rubber return lines, etc except for the pump and injectors). The tank had a few teaspoons of rust and algae in it, no sock filter in the fuel sump. I also noticed once I removed the old filter assembly that all of the return lines at the injectors (passenger side) immediately started seeping diesel, but not on the driver side. I went ahead and ordered those lines too. This vacuum pull system apparently doesnt leak diesel out, instead weak spots suck air in. Totally opposite of a pressurized gasoline fuel system. Very bizarre cause and effect but this video made everything make operational sense. The customer also states this truck has also been to multiple shops and never truly fixed.

2002 lb7  Owner here. Thanks for the info 👍 😀

Thanks Tony for such a clear, concise video explaining how the early Duramax fuel system functions. I have subscribed to your channel and plan to see all of them. Thanks again!

Great video I definitely learned a lot thanks

Awesome video Tony , very informative for a chevy novice like myself, thank you thank you

Very nice presentation.

WOW,  you are my new diesel god. GREAT instruction.

i learned plenty today thank you sir

Thank You.!

simply and clearly explained

Spent days researching why fuel is being pumped back to tank and never creating pressure! Finally the best breakdown of a system without u tube nonsense Thankyou for making this video I'm finally clear where my problems may be.

Fantastic video! Thank you for making this content!