Hi everyone,

I have a 1998 chevy blazer 4 door 4wd 184k on her. I had a whining fuel pump and not much cash. I had offers of repairs from $400 (street mechanic) to $700. I shopped around and found a shop that would do it for $570. I know this is no easy job and for a certified shop for this price with a 12mo 12k warranty I figured he was my best bet. WHAT A MISTAKE!!!
3 weeks ago I get the pump replaced and as soon as I get home and out of the car ( drivers side) I smell gas the smell last about 1 minute then goes away. I figured OK, Spillage, well 5 days later not only am I still smelling gas but the check engine light is coming on and off. Back to the shop it goes. 2 days later they say the can not find a leak, (Can smell the gas) could not get the check engine light to come on to check the code so to be safe they "say" they dropped the tank and added some lubricant to the seal ring. So I get the car back and same thing.. smells of gas at red lights and getting out of her, and the check engine light is back on. Back to the shop after a screaming match with the owner. He swears up and down no leaks and the fuel pump was put in correctly. Anyway he takes her back in, keeps her for 5 days and now the check engine light doesnt shut off so he can read the code which is P0440. He refuses to change the pump out even though I have a warranty, he said if it was a faulty pump it would effect performance??
( Which it is not.) He tells me change my gas tank cover and if thats not it then ill need a canister big $$$. I google the code and it can be all sorts of things. I call a few shops and they want $200 just to drop the tank and see if there is a problem with the seal ring. What do I do? I get a fuel pump and now have a gas smell and check engine light and code and for the 5 days I called they just kept saying we cant find a problem, its safe to drive.. I do not want to drive her like this, meanwhile 3 weeks after fixing the fuel pump im taking buses on a sprained ankle.. I cant afford to bring it elsewhere and he just sits on it when I bring it in. Any suggestions??

 

Welcome to the Blazer forum Michie. You, of course, should not run/drive it with a known fuel leak. A PO440 generally indicates a 'leaky' EVAP emmission control problem (loose or bad gas cap, tank filler neck/hose(s), fuel pump/sending unit O-ring seal and locking ring, tank vent valve(s), hoses, charcoal canister/solenoid, etc. The first thing to do with a PO440 code is to make sure that the gas cap is tight and that the cap's O-ring seal isn't torn or damaged due age, etc. The cap can also be bad even tho it's tight and the seal looks good...

However, I suspect a broken plastic vent valve (located on top of the tank) and/or a disconnected vent valve hose. It's not uncommon for these valves to be broken during the tank removal/installation procedure. Nor is it uncommon for these hoses to be left disconnected during such jobs.

Most, if not all, Blazers have an easily broken plastic 'L' shaped vent valve located towards the front of the tank and another near the rear next to the fuel pump/sending unit (the front valve is often overlooked while removing the tank which, often leads to it being broken off completely. Inexperienced mechanics and DIYers don't always notice that this front valve has been broken off and, as such, carry on with the job as if nothing is wrong.

Checking these vent valves and vent valve hoses yourself usually requires safely raising the rear of the vehicle enough (on jack stands) to get under it so as to inspect them visually (or by feel). This also gives you the chance to look for signs of fuel leakage at or around the vent valves, the filler neck, the fuel pump/sending unit output and fuel return lines, as well as the FP/sending unit O-ring and locking ring (these metal locking rings can be tricky to remove and re-install and are often damaged enough during removal so as to require replacement.

Not sure if you want to check these things yourself but, if you do, always make sure that you work in a safe and well ventilated area away from open flames (i.e. residential water heaters and gas furnaces, etc). Also make sure that you wear approved safety glasses whenever you work on your vehicle.

 

Thank you FMB42.
I am not able to do these checks myself. However the mechanic swears up and down there are no leaks. It was my first time going to him as I just recently relocated. At this point my hands are tied, when I force the car on him he just sits on it, with this type of person I decided its best to get it away from him before he reports it as abandoned or something. Now I have to leave her sit until I can pay someone else to look at her and they want alot to drop that tank. I cant believe the position he put me in leaving me in this situation with a drained bank account. I am considering court but do not know how that works in these situations, I never sued anyone but this is outrageous. I have text telling me she is safe to drive, what idiot says its ok to drive with a fuel or fume leak? IDK where to turn without waiting weeks to a month to get her looked at.

 

A good shop should be able to check the tank for most of the above mentioned leak 'points' without dropping the tank. The exception to this would possibly be the FP/sending unit 0-ring seal and lock ring. They might be able to determine if the O-ring/lock ring area is leaking without dropping the tank (but if it is they'll need to drop the tank in order to make the necessary repairs).

Meanwhile; a leak at the filler neck would likely be more noticeable while filling the tank and/or when the tank is full. Btw, you should never 'top-off' the fuel tank. Filling should be stopped after the 1st or 2nd 'click' of the gas station pump (while set to ~ 'half' fill speed).

A leak at the fuel return line would likely be noticeable any time the fuel pump is running while leaks at the vent valves are typically noticed while driving or parking on inclines or hills (or whenever the tank is at, or near, full.

As for the plastic vent valves; they can, with some difficulty, be replaced without dropping tank. As mentioned above, these valves are pretty easy to break while removing and/or installing the tank. These valves cost ~ $20 each with about an hour for labor to replace both (or ~ 40 minutes for just one). These estimated costs are, of course, 'ballpark' figures.

 

Thank you again FMB42. I called a dealer he said usually with my complaints after installing a fuel pump it is because the vent line was not reconnected. He said he could start there. He is unfortunately more then a 1/2 hr ride from me and offcourse while he says its 99% certain thats the issue until he gets under there.....

 

Well the dealer did the smoke test, was coming from the fuel pump. 2 tows and 150 bucks later I had the letter from the dealer, the garage replaced it. I have a nice picture of the broken O ring for the fuel pump. swear im still getting very quick and passing whiffs of gas./ Maybe its just in my head idk..

 

Yep, those big F/P Sending Unit O-rings are pretty easily torn or cut if it, and the parts it seals to, aren't lightly oiled or greased (with petroleum jelly) prior to assembly. Another thing is that the lock ring can be pretty tough to remove once they get some years on them. Old lock-rings are often damaged beyond hope while removing them which is why many mechanics often replace them with a new L-ring just to be safe.
Meanwhile, let's hope that the tank F/P S/U 'access' hole lip/edge wasn't bent/damaged enough to allow fuel leakage.