1980 BMW 320i Gas tank leaks when full - United Bimmer Community

**orlydj1** · 03-16-2008, 08:15 AM

Hi to all,

My question is what is the easiest way to replace the gas tank vent hoses that are on top of the tanks. I really do not want to remove the tanks all the way. Also can I use regular standard size hoses with clamps or do I need to buy metric size. Any diagrams or step by step instuctions are appriciated.
It only leaks when I fill the tanks to the top.

**3050rpm** · 03-16-2008, 03:31 PM

I'm not sure, but you may be able to do it simply by gaining access after removal of the rear seat, you would then be staring right at the top of the tank. It might be a good idea to replace the seal at the same time. I don't know about hose sizes, but I imagine any half-way decent parts place would be able to get you exactly what you need, and you might even do all right by checking with the dealer.

**orlydj1** · 03-16-2008, 11:47 PM

Hi 3050 RPM

I already took the rear seat off, also port cover. Took the car to the gas station filled it up and found "No Leak" from the O ring in the sender unit nor from the hose's that were visible. Almost positive the leak is from the left and right vent hose's that are not accesable from the fuel sender port.
Today the oxygen sensor light turned on. I have to research that also.

Thanks 3050 RPM

**Numark318i** · 03-17-2008, 02:03 AM

remember to disconnect the battery before working on your fuel tank.

**3050rpm** · 03-17-2008, 12:59 PM

Well I was hoping the simple approach would do it, but guess not, I guess the tanks will have to be dropped. I don't know if there's a Bentley manual that covers the E21s, but there is a Hanes, and a couple of others I'm sure. Yeah, a bit of a pain, but seeing as those hoses dry out and crack, it's best to get at the whole thing, and also check the connections while you're at it. And for certain, take the necessary precautions when working around gasoline.

**orlydj1** · 03-18-2008, 02:23 AM

Thanks

Look's like I will be looking for a shop to help me out. If I get the right price I will let them do it. In the mean time I will ride on a 1/4 tank. Will let you know.

**3050rpm** · 03-18-2008, 07:55 AM

I don't think it's so much a complicated job, as you just need the right setting to do it in, and that means putting the car up on a lift. Not too many of us have that in our garage. In the meantime you're right, just don't fill the tank all the way up, I don't think you have to limit yourself to just 1/4 of a tank though, I think you could do just fine with 9-10 gallons, just to make things a bit more convenient for you. I think the 320i has a 12 gallon tank.

nick_318is · 03-18-2008, 05:31 PM

My e30 leaks a little with a full tank but only on hard cornering, I have heard this to be the case with others as well.

**orlydj1** · 03-21-2008, 07:56 AM

I called Dinan in Morgan Hill, and asked if the tanks needed removal to replace the vent hoses. Called Dinan becuase I'm only 2 blocks away and well " Dinan" what's better then Dinan. The guy I spoke with told me to bring the car in. I spoke to the mechanic and gave him a new fuel filter. I told him that I took out the rear seat the sender port cover and found after filling the gas tank that the O-ring on the sender was not the source of the leak. (My girlfriend fill up the tank, I observed the sender unit from inside the car. Still leaking gas. It took about $36 in gas.) Dinan installed the filter and I was told they replaced the leaking fuel hose's. I left Dinan $125 short and thought I got a deal. Next day I refilled the tanks and was pissed to find gas leaking. Called Dinan asked why I was led to believe the hose's were replaced. They wanted, after some sarcacism, $800 to remove tanks. Went to 2 other shop's was quoted $300 - $350 plus parts. The 3rd shop Morgan Hill gas, Oriental mechanic's charged me $150 labor $50 parts plus tax, problem fixed for $208 plus $125 rip off by Dinan.

**3050rpm** · 03-21-2008, 01:24 PM

I gather this did involve dropping the tanks. All in all, not a bad price you eventually paid to get the job done right, certainly a bargain in comparison to your having to do it yourself. Sorry to hear of the run-around and baloney you previously encountered, you'd think people would be interested in helping out an enthusiast, rather than take advantage of one.

denyo77 · 03-22-2008, 08:24 AM

^+1

makes you angry when you hear stuff like that