I have air leaking into my fuel line

[BeratE]

I have had my engine cough for a while now, and so I replaced the fuel lines in the engine bay with diesel safe clear lines so that I could see what is going on. I have found that there are no bubbles before the fuel primer, but there are frequently bubbles in the line from the fuel primer to the IP. I thought there might be an issue with the primer itself, so I bought a new one from Japan. At that time I installed a new fuel filter as well, but the problem persists. I don't know where else the bubbles could be coming from. Wigging the hoses themselves doesn't appear to increase or decrease the bubble count. Is it possible that air is coming in somehow from the water sensor on the bottom?!?

[Sir Plug]

I have had my engine cough for a while now, and so I replaced the fuel lines in the engine bay with diesel safe clear lines so that I could see what is going on. I have found that there are no bubbles before the fuel primer, but there are frequently bubbles in the line from the fuel primer to the IP. I thought there might be an issue with the primer itself, so I bought a new one from Japan. At that time I installed a new fuel filter as well, but the problem persists. I don't know where else the bubbles could be coming from. Wigging the hoses themselves doesn't appear to increase or decrease the bubble count. Is it possible that air is coming in somehow from the water sensor on the bottom?!?

Did you change the o ring?

[BeratE]

Thanks for the response. Yes, the o-ring was replaced when the new fuel filter went in. I don't suppose that could have gotten botched somehow, could it?

[NiftyNev]

What about the small oring on the drain tap itself?

Nev

[BeratE]

Dang, I didn't touch that one. Have you ever seen this part leak air in but no fuel out?

[legendgamesmaster]

us too....

hmm.....

mate has the same issue with his hilux pickup.

there must be an air leak in there somewhere! We'll try the o ring thing.

keep this thread informed please!

[Chris QTown]

Mines been harder to start these past few months so I installed a new primer. Now my truck takes 10 seconds to start if i dont prime it, only 3 seconds if i do.
Ergo I must have an air leak. Wouldn't mind getting some of these clear hoses you speak of to get a better idea where its leaking .
Will check the bottom of ring now you have mentioned it Nev.
When I prime it, it will drop 1 or 2 drops of diesel out the bottom of the drain tap, I assume that's normal.... ?

[Yorkshire Devil]

Mines been harder to start these past few months so I installed a new primer. Now my truck takes 10 seconds to start if i dont prime it, only 3 seconds if i do.
Ergo I must have an air leak. Wouldn't mind getting some of these clear hoses you speak of to get a better idea where its leaking .
Will check the bottom of ring now you have mentioned it Nev.
When I prime it, it will drop 1 or 2 drops of diesel out the bottom of the drain tap, I assume that's normal.... ?

By pass the fuel filter housing and see if the problems persist?

[Chris QTown]

Took it to Toyota. They've told me i have 1 or 2 leaking injectors.
$3000.00 to fix!!!!!

[BeratE]

I have not been able to find the info on the hoses that I put in. I installed them some years ago and if I could only find out the material, you ought to be able to source them. I will keep looking. After 3 years of use, the only change to the clear lines was discoloration inside the hose where there was contact with the fuel. The hoses were not any more brittle or soft, and appear to not have degraded at all.

On the original note, I just finished installing a Racor 230R2 filter and head in place of the factory setup. I used AN-6 fittings on the hose ends, including at the injection pump, which removed the banjo fitting there. As it is now, the filters are a little cheaper, there is a clear fuel bowl at the bottom to see any water, the filter is impervious to water, the priming mechanism is much better and is repairable, and best of all, I have no more air entering the system.

Moral of the story seems to be that even buying a factory new fuel primer might not fix the air entering the system. The Racor unit was reasonably priced, has a micron rating of 2, filters can be found world wide, everything is easily repairable and replaceable, and the engine will stop rather than let water through if I get a bad batch of fuel. Highly recommended! On top of that I installed a vacuum gauge on the outlet of the filter so I can monitor the resistance of the filter as it ages.

I do think that I have a tired injector or two, as it still starts a little rough, but once running I can feel the truck running smoother than before.

In regards to $3000 for a injector job, I suggest you tell the dealer where they can stick those injectors! Just buy new nozzles and have a diesel shop rebuild your existing injectors.

edit: the site I bought my clear tubing from was mcmaster.com and it looks like th part number for 3/8" line I used was 5549K37