Fuel filter bubbles

[1968RRTEXAS]

Good evening Mopar family. Is this normal operation for the fuel filter. The mechanic in me thinks that it means it's sucking air.

 

[Redcreekauto]

It does appear to be sucking air. However today's fuel blends will bubble up with that sort of vibration. How full was your tank?

 

[1968RRTEXAS]

It does appear to be sucking air. However today's fuel blends will bubble up with that sort of vibration. How full was your tank?

I just topped it off last weekend.

 

[Redcreekauto]

I would change out all rubber lines first. Chances are best that is where you would have issues but its possible that you have a rusted or cracked metal lines. Also a hole in the fuel pump diaphragm can cause that as well. If your not seeing obvious leaks on or around your fuel lines then pull your oil dipstick. You can usually smell raw fuel mixed with oil. That is if the fuel pump itself is the culprit.

 

[1968RRTEXAS]

I would change out all rubber lines first. Chances are best that is where you would have issues but its possible that you have a rusted or cracked metal lines. Also a hole in the fuel pump diaphragm can cause that as well. If your not seeing obvious leaks on or around your fuel lines then pull your oil dipstick. You can usually smell raw fuel mixed with oil. That is if the fuel pump itself is the culprit.

Excellent advice. I have traced the supply line all the way back and can't visibly see a leak. I will check the dipstick. Ever since I filled up the tank my garage has had a gas smell to it (wife not happy) but at 1/2 tank it never emitted fumes....

 

[Yatzee]

Expansion of the fuel increases pressure in the tank especially when heat causes the fuel to start to evaporate. The pressurised fuel vapors have to go some where and that's usually out the vent in the cap ( if there is a small hole present in the cap)or up the fuel line as gas bubbles. At half tank, there is enough empty space above the gasoline to accommodate the vapors without over pressurising the tank. Remove the gas cap to depressurise the tank and see if there's bubbles in the fuel when the engine's running.

 

[1968RRTEXAS]

Expansion of the fuel increases pressure in the tank especially when heat causes the fuel to start to evaporate. The pressurised fuel vapors have to go some where and that's usually out the vent in the cap ( if there is a small hole present in the cap)or up the fuel line as gas bubbles. At half tank, there is enough empty space above the gasoline to accommodate the vapors without over pressurising the tank. Remove the gas cap to depressurise the tank and see if there's bubbles in the fuel when the engine's running.

Great minds think alike lol

I removed the fuel cap while it was running and it made no difference with the fuel filter. Shouldn't the fuel filter be full as well?

 

[Mike67]

X2 on a cracked diaphram....the bubbles are a consistant pattern... Do they increase with rpm?

 

[1968RRTEXAS]

X2 on a cracked diaphram....the bubbles are a consistant pattern... Do they increase with rpm?

I will have to check and provide feedback

 

[Yatzee]

Well, if you suspect the pump you could always draw a vacuum at the outlet or inlet side and see if it holds. If not, the internal valves are leaking, the diaphram has holes in it or the case seal is poor on the inlet (suction) side. Or, just go out and purchase a new pump and try "repairation by substitution" if you can afford it.

 

[1968RRTEXAS]

Well, if you suspect the pump you could always draw a vacuum at the outlet or inlet side and see if it holds. If not, the internal valves are leaking, the diaphram has holes in it or the case seal is poor on the inlet (suction) side. Or, just go out and purchase a new pump and try "repairation by substitution" if you can afford it.

Great suggestion. Thank you

 

[1968RRTEXAS]

I would change out all rubber lines first. Chances are best that is where you would have issues but its possible that you have a rusted or cracked metal lines. Also a hole in the fuel pump diaphragm can cause that as well. If your not seeing obvious leaks on or around your fuel lines then pull your oil dipstick. You can usually smell raw fuel mixed with oil. That is if the fuel pump itself is the culprit.

Your were on the money. I smell fuel mixed with oil on the dipstick. Any recommendations on brand of fuel pump to go with.

 

[Lionized]

Your were on the money. I smell fuel mixed with oil on the dipstick. Any recommendations on brand of fuel pump to go with.

Carter.

 

[Richard Cranium]

This thread needs a theme song...........

 

[1968RRTEXAS]

Well, if you suspect the pump you could always draw a vacuum at the outlet or inlet side and see if it holds. If not, the internal valves are leaking, the diaphragm has holes in it or the case seal is poor on the inlet (suction) side. Or, just go out and purchase a new pump and try "repairation by substitution" if you can afford it.

Hooked up the vacuum gauge pump. I couldn't get any vacuum to hold for even a second. The part# on the carter fuel pump is 0-1994, I don't know if this is the correct pump. Hopefully ill be replacing it next week. Thanks again

 

[moparedtn]

Mancini sells the original Carter "hemi" fuel pump that is being reproduced:
http://www.manciniracing.com/cam6bisumefu.html
Bonus is that it is identical to the original and is as a result rebuildable.
I don't know if it will be too much for your engine, but it works great on my 440.