Fuel Leak - Dealer says something wrong with sending unit

[hornsfan10609]

Some short self tappers? You may have to get a JY gas tank if it comes down to it, but I bet you can make it work with some new screws/bolts.

 

[livelyjay]

So instead of using the OEM screw holes, rotate the flange so I'm in the middle of the OEM holes, then use short self tapping screws? I'd worry about getting metal into the tank, but I could run the shop vac next to where I'm drilling (or cover tank with a towel). Is that where you're going with that idea? If so, I like the sound of it.

 

[MaxPower]

There's a thread covering this in extensive detail...
http://www.mazdas247.com/forum/showthread.php?123718385-Has-Anyone-Had-Their-Fuel-Pump-Cover-Leak

 

[hornsfan10609]

So instead of using the OEM screw holes, rotate the flange so I'm in the middle of the OEM holes, then use short self tapping screws? I'd worry about getting metal into the tank, but I could run the shop vac next to where I'm drilling (or cover tank with a towel). Is that where you're going with that idea? If so, I like the sound of it.

That sounds even better, you may have to drop the tank if you really want to ensure no shavings get in there.

 

[livelyjay]

I already read the thread MaxPower linked to, but not every post in there. It appears there are many solutions to the screw problem. I'll read through that thread in more detail when I'm ready to do the work, gather up the screws, taps, etc so I don't need to run all over the place when I'm actually doing the work. I'm thinking drilling out the screw at 8mm, retapping at OEM size will be by first attempt, second being drilling and tapping to next largest size.

Last resort is dropping the tank, and if I have to do that, I'll just replace the damn thing.

 

[livelyjay]

Just as an FYI to anyone who might read this, the OEM screws are 4mm x 8mm thread pitch is .70 as I compared the taps from my friends kit that I borrowed. Off to the hardware store to buy 5/32 (3.969mm) and 11/64 (4.366mm) self tapping screws.

 

[livelyjay]

Just ran some errands and picked up self tapping screws. When I got home I pulled the access door and the fuel pump cover was covered with gas. So my guess as to where the leak was coming from was dead wrong I drilled out one of the screws, ran the tap through the hole, and put in an OEM sized, stainless, hex bolt. It appeared to hold tension, so I think I'm going to be good to go with this repair. I'll snap some pictures along the way tomorrow.

 

[hornsfan10609]

Good to hear!!

 

[livelyjay]

Doing work in this cold ass weather sucks, and I can't use the propane heater for obvious reasons (flame). After pulling the pump I realized when I drilled out the screws I went all the way through into the tank. I went to the auto parts store and bought some silicone gasket stuff that's fuel resistant. I put a THICK bead of it over all the screw holes, put everything back together, and cranked down the screws. The gasket material oozed around the metal cap, so I have a good feeling that will prevent fuel from seeping up the screw threads. If fuel does seep up, I'll have Mazda replace the tank in the spring.

 

[livelyjay]

Drove for a bit today. Gas is leaking up through the screw holes that I drilled through. Anyone got any tips? If not, the car is going to the dealership for a new tank this week. At least I saved some money that the dealership would have charged me for the pump assembly.

 

[MaxPower]

You can try JB Weld.

 

[livelyjay]

I thought about that and did some research. JBWeld isn't 100% resistant to gas. Their website recommends Water Weld, which is a putty like material. Right now I'm just running the tank down and when it's low enough I'm going to use the putty and make a full ring around the underside of the flange, scoring it with a utility knife so it has more to grip to, and hopefully that will work. If it doesn't, off to the dealership for a new tank.

 

[livelyjay]

Anyone still following this ... the fuel leak appears to be resolved. I used JB Weld Water Weld inside the tank to seal up the holes where I drilled into the tank. The putty was nasty stuff to work with and liked to stick to my gloves and not the tank. I let it cure for two days before I sealed everything back up, then it was a few more days before I could drive the thing and fill up the tank. Filled it and 3/4 of a tank later I have no fuel smell at all. Pretty sure this one is fixed, at least for now. JBW WW says it has a two year life, so I'll have to keep my nose open and see if the fix lasts.

 

[hornsfan10609]

Good luck with it!