HMMWV Fuel Line Check Valves

[GTUnit]

Does anyone know the final word, engineering reasons, these fuel line check valves were included by AM General?
What specific issue(s) are they there to fix?
What possible side effects would permanently removing them cause?

 

[Maxjeep1]

I removed mine. It takes so much pressure to open them. I left them in my other truck but when I replace fuel lines they will be gone

 

[Autonomy_Lost]

I had a check valve fail on a jeep once. When you shut the vehicle off, the fuel would eventually run back into the tank and you'd lose your prime. The next time you tried to start it, it would take considerable time for the fuel to fill the lines again.

What check valve(s) are on the humvee? Are there redundant check valves that you are considering removing?

 

[Maxjeep1]

I had a check valve fail on a jeep once. When you shut the vehicle off, the fuel would eventually run back into the tank and you'd lose your prime. The next time you tried to start it, it would take considerable time for the fuel to fill the lines again.

What check valve(s) are on the humvee? Are there redundant check valves that you are considering removing?

They have 2 of them towards the front of the tank up high. Supply and return.

 

[86humv]

There's a third check valve on 90's and up trucks on fuel filter housing....its a weak one and should be fine leaving it.

 

[Guyfang]

There are, two schools of thought here.

If it was not needed, why would the military have them on the truck? They are there for a reason. Keeping fuel from draining back in the system, and causing non starts, or engines starving for fuel, until the fuel pump fills the lines back up.

Yes, they are a PITA. When you allow the fuel system to coat itself with lacquer, the check valve will stop passing fuel, and the engine starts working. Tossing in some off the shelf liquid to clean out the lacquer, will prevent this from happening. The simple solution is to simply remove it. Simple is not always the best.

 

[Maxjeep1]

There are, two schools of thought here.

If it was not needed, why would the military have them on the truck? They are there for a reason. Keeping fuel from draining back in the system, and causing non starts, or engines starving for fuel, until the fuel pump fills the lines back up.

Yes, they are a PITA. When you allow the fuel system to coat itself with lacquer, the check valve will stop passing fuel, and the engine starts working. Tossing in some off the shelf liquid to clean out the lacquer, will prevent this from happening. The simple solution is to simply remove it. Simple is not always the best.

So the return has one also? Did they put it there to keep fuel from running back into the injectors? I still have mine and if I have issues I will put them back in…

 

[GTUnit]

There are, two schools of thought here.

If it was not needed, why would the military have them on the truck? They are there for a reason. Keeping fuel from draining back in the system, and causing non starts, or engines starving for fuel, until the fuel pump fills the lines back up.

Yes, they are a PITA. When you allow the fuel system to coat itself with lacquer, the check valve will stop passing fuel, and the engine starts working. Tossing in some off the shelf liquid to clean out the lacquer, will prevent this from happening. The simple solution is to simply remove it. Simple is not always the best.

So bad diesel creates a laquer film as well much like old gasoline? We left the gas in my dads Snowmobile for over a year and I spent hours stripping those carburators down into loose pieces and having it all dipped at a pro shop to get all the sticky crud resistant to EVERY solvent I could find off it.

 

[Milcommoguy]

So bad diesel creates a laquer film as well much like old gasoline? We left the gas in my dads Snowmobile for over a year and I spent hours stripping those carburators down into loose pieces and having it all dipped at a pro shop to get all the sticky crud resistant to EVERY solvent I could find off it.

AND the smell of rotten stale gas... PU, CAMO