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On a 2012 mack mp8 engine can u tell me exactly where this…

on a 2012 mack mp8...
on a 2012 mack mp8 engine can u tell me exactly where this fuel check vavle is on the front of the head ,if its on driver or passenger side
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Answered in 4 minutes by:
3/18/2021
Technician: Mike Mcmillan, Shop Foreman/Triage Tech replied 1 year ago
Mike Mcmillan
Mike Mcmillan, Shop Foreman/Triage Tech
Category: Medium and Heavy Trucks
Satisfied Customers: 6,427
Experience: Volvo/Mack Master Tech, Certified with Cummins, Eaton, GM, Hino, Detroit Diesel
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Hello and thank you for using Just Answer. My name is ***** ***** I’d like to try and help. Please allow me a few moments to look over your question and I will be right back with you. Thank you
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Technician: Mike Mcmillan, Shop Foreman/Triage Tech replied 1 year ago
The overflow valve is right in front of the head facing the engine fan. It takes a 7/8 wrench to remove it. There is only one fuel line that goes in the middle area of the front of the head and the overflow valve holds that fuel line into the head. I hope this helps you with your question. Thank you
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Customer reply replied 1 year ago
i ahve changed out the injector cups and the over flow valve now and both still did not change nothing on the ruck it still just cranks and hard to start ,u have been helping me on the 2012 mack engine mp 8 hard to start if u didnt rememberis there any testi can do to find the problem
Technician: Mike Mcmillan, Shop Foreman/Triage Tech replied 1 year ago
Are you getting any air out of the return
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Customer reply replied 1 year ago
on the passenger side
Technician: Mike Mcmillan, Shop Foreman/Triage Tech replied 1 year ago
Did you torque the injector cup install tool when installing the cups? And put diesel near the tip of the injector when installing?
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Customer reply replied 1 year ago
to sixty I put that sealant mack dealer gives with cups
Technician: Mike Mcmillan, Shop Foreman/Triage Tech replied 1 year ago
See if there is a T fitting on top of the 7th injector. If there is remove the fuel line and see if any air is passing thru it
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Customer reply replied 1 year ago
k let me try that
Customer reply replied 1 year ago
okay it does have a t do i pull lines off while its running or just able to turn key on and hear air goin throu it
Technician: Mike Mcmillan, Shop Foreman/Triage Tech replied 1 year ago
Just make sure the air system is aired up and leave the key on and spray soapy water where the fuel line threads onto the side of the T with the line off
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Customer reply replied 1 year ago
i did pull line off and made sure sysem was aired up and no air is leaking throu
Customer reply replied 1 year ago
what is my next step
Technician: Mike Mcmillan, Shop Foreman/Triage Tech replied 1 year ago

If you are still getting air out of the return you have an air ingestion issue. I usually make up some clear sight hoses and start placing them around the engine to make sure you do not have any air on the chassis side. You may have an injector that is passing air thru the tip and leaking off when you shut the engine off, or a fuel pump that is picking up air.

Mike Mcmillan
Mike Mcmillan, Shop Foreman/Triage Tech
Category: Medium and Heavy Trucks
Satisfied Customers: 6,427
Experience: Volvo/Mack Master Tech, Certified with Cummins, Eaton, GM, Hino, Detroit Diesel
Verified
Mike Mcmillan and 87 other Medium and Heavy Trucks Specialists are ready to help you
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Customer reply replied 1 year ago
could my fuel filters have anything to do with it
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Mike Mcmillan
Mike Mcmillan, Shop Foreman/Triage Tech
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