Trumbull_welding Posted September 13, 2023 Share Posted September 13, 2023 IMG_0020.MOV Good evening all, Working on 2007 Mack CV713 they’ve been running the truck it looses power, upon filter change the truck runs better but eventually bogs down again, its a very hard prime and once running you can see bubbles in the clear fuel filter housing and the bubbles do continue after the truck is shut down what is the best way to test the fuel system to pin point the area causing the issue. Tanks do not appear to be dirty, bubbles in the drivers side tank i be leave is from the return line spraying into the tank and aerating from the stream not necessarily from air in the fuel, and there’s no visible leak around the primer pump, have not yet checked any check valves. Any help or advice on how to best proceed is greatly appreciated hope you are all well. Thank you- Chris Quote Link to comment https://www.bigmacktrucks.com/topic/73303-2007-mack-cv713-hard-to-prime-and-bubbles-in-fuel-filter-housing%C2%A0/ Share on other sites More sharing options...
Joey Mack Posted September 13, 2023 Share Posted September 13, 2023 Does it have a Davco 382 fuel water separator filter? Quote Link to comment https://www.bigmacktrucks.com/topic/73303-2007-mack-cv713-hard-to-prime-and-bubbles-in-fuel-filter-housing%C2%A0/#findComment-538763 Share on other sites More sharing options...
Trumbull_welding Posted September 13, 2023 Author Share Posted September 13, 2023 21 minutes ago, Joey Mack said: Does it have a Davco 382 fuel water separator filter? I believe all it has is the Davco filter housing in the video above no separate fuel water separator. Quote Link to comment https://www.bigmacktrucks.com/topic/73303-2007-mack-cv713-hard-to-prime-and-bubbles-in-fuel-filter-housing%C2%A0/#findComment-538767 Share on other sites More sharing options...
Solution Popular Post Joey Mack Posted September 13, 2023 Solution Popular Post Share Posted September 13, 2023 Ok.. I just saw the video, the large o-ring at the base of the globe is leaking air.. that is the problem.. drain it down to just below the globe. Clean and inspect the o-ring. Clean the lock ring and globe flange. Re - install and only pour enough fuel to show 1 inch of fuel, and re - test. That air leak is common, but can be avoided by keeping it clean. There is also a check valve inside the big input fitting. They are about $10.00, and well worth replacing.. it is easy to do.. Jojo 2 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73303-2007-mack-cv713-hard-to-prime-and-bubbles-in-fuel-filter-housing%C2%A0/#findComment-538769 Share on other sites More sharing options...
Trumbull_welding Posted September 13, 2023 Author Share Posted September 13, 2023 Got the parts headed to give it a shot now I’ll keep you posted thank you sir -Chris Quote Link to comment https://www.bigmacktrucks.com/topic/73303-2007-mack-cv713-hard-to-prime-and-bubbles-in-fuel-filter-housing%C2%A0/#findComment-538792 Share on other sites More sharing options...
Joey Mack Posted September 13, 2023 Share Posted September 13, 2023 (edited) good deal.. just make sure the globe and its flange is clean, and the filter housing too. the o-ring goes on the end of the globe, not under the ring... the ring is just a big plastic nut. You got this... Edited September 13, 2023 by Joey Mack I made a Boo Boo Quote Link to comment https://www.bigmacktrucks.com/topic/73303-2007-mack-cv713-hard-to-prime-and-bubbles-in-fuel-filter-housing%C2%A0/#findComment-538793 Share on other sites More sharing options...
Trumbull_welding Posted September 13, 2023 Author Share Posted September 13, 2023 (edited) Seals and check valve looked ok they didn’t have a double gasket stuck under the filter I gave it a new filter and o-rings and changed the check valve the fuel looks clean I did notice a black film on the inside of the metal portion of the filter housing I’ll add few pictures here. Dumping some fuel in now and trying to fire it..also when I got to the truck today the housing was draind down to about an inch below the inlet port in the housing Edited December 18, 2023 by Trumbull_welding Quote Link to comment https://www.bigmacktrucks.com/topic/73303-2007-mack-cv713-hard-to-prime-and-bubbles-in-fuel-filter-housing%C2%A0/#findComment-538796 Share on other sites More sharing options...
Joey Mack Posted September 13, 2023 Share Posted September 13, 2023 Perfect, did you loose fuel prime? if so, you can crack #2 and #4 or #5 line at the head and pump the primer til they bleed then lock'em down... it will fire up with-in 10 seconds.. Quote Link to comment https://www.bigmacktrucks.com/topic/73303-2007-mack-cv713-hard-to-prime-and-bubbles-in-fuel-filter-housing%C2%A0/#findComment-538797 Share on other sites More sharing options...
Trumbull_welding Posted September 13, 2023 Author Share Posted September 13, 2023 No sir didn’t lose prime just bleed back to the tank I guess it fired right off and no bubbles I was worried it was gonna be an injector I’ll let it run for a few and make sure it dosent start with any bubbles then shut down and make sure nothing leaks back Quote Link to comment https://www.bigmacktrucks.com/topic/73303-2007-mack-cv713-hard-to-prime-and-bubbles-in-fuel-filter-housing%C2%A0/#findComment-538798 Share on other sites More sharing options...
Joey Mack Posted September 13, 2023 Share Posted September 13, 2023 I told you ... those check valves are cheap, and important.. good job Bud.. Jojo Quote Link to comment https://www.bigmacktrucks.com/topic/73303-2007-mack-cv713-hard-to-prime-and-bubbles-in-fuel-filter-housing%C2%A0/#findComment-538800 Share on other sites More sharing options...
Joey Mack Posted September 13, 2023 Share Posted September 13, 2023 I look forward to an update. I am quite sure the bleed back issue is fixed... you could put a piece of tape on the globe at the fuel level, and go drink a beer or few, then come back to see if it dropped.. Just sayin'..... 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73303-2007-mack-cv713-hard-to-prime-and-bubbles-in-fuel-filter-housing%C2%A0/#findComment-538801 Share on other sites More sharing options...
Popular Post Trumbull_welding Posted September 14, 2023 Author Popular Post Share Posted September 14, 2023 Hahaha I coulda gone for a beer and sorry had some other trucks to work on too but yes sir that one is all set thank you very much ! 3 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73303-2007-mack-cv713-hard-to-prime-and-bubbles-in-fuel-filter-housing%C2%A0/#findComment-538815 Share on other sites More sharing options...
Joey Mack Posted September 14, 2023 Share Posted September 14, 2023 Thanks for posting the repair. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73303-2007-mack-cv713-hard-to-prime-and-bubbles-in-fuel-filter-housing%C2%A0/#findComment-538819 Share on other sites More sharing options...
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