Gas leaking from top of tank...

Driving to work yesterday, front left brake caliper seized. Took a good pull on the wheel to keep things straight, and there was a nice bit of smoke by the time I got there. Not a big deal, a new caliper fixed things up, and I made it home on time. Of course, when it rains...

Filled up with gas on the way home. Parked at Home Depot to check out a tool box. When I came out, I noticed a puddle behind the left rear wheel. Smelled it, it's gas. Looks to be running down from the top of the tank. I have noticed that the car smelled vaguely like gas when walking around the back lately, but there has been no drip. I guess the latest full tank pushed it over the edge. There was a puddle as soon as I parked at work today, too, so it doesn't look like it is caused only by a "full" tank. I've driven about 30 miles since I filled it.

So, what are the possibilities? Rotted out sender? Broken return fuel line? I know, the tank has to come down. Just want to get prepared. If it is the sender, will the one out of my parts car Fleetwood work?

From personal experience, sending unit rotted.

Tom

silverfox103 wrote:

From personal experience, sending unit rotted.

Tom

x2. That was part of my issue when my car kept stalling the line that ran to the motor had a leak and was causing fuel starvation.

I'll check Rockauto and see if the sender for the Cadillac crosses to the wagons.

Saved this posting from Joel, 3 years ago:

https://gmlongroof.4umer.com/t667-sending-unit-rust-repair

Tom

jayoldschool wrote:

I'll check Rockauto and see if the sender for the Cadillac crosses to the wagons.

Someone smarter than me may disagree but since the wagons are an entirely different part number than sedans. Chances are it won't fit. Wagons are FG127A and sedans are 128A.

Yes, the Cadillac is 128B. No idea what the differences are, but I'm going to find out!

jayoldschool wrote:

Yes, the Cadillac is 128B. No idea what the differences are, but I'm going to find out!

I think the float arm is a different size to accommodate the larger size of the sedan tank to the wagon.

Well, that should be easy enough to swap over. Joel? Can you swap arms?

Rock auto has wagon-specific assemblies. Why dick around?

FYI, TBI senders work on LT1 cars. Swap the pump and the plastic clips that hold the lines on and roll.

jimbeau wrote:

Rock auto has wagon-specific assemblies. Why dick around?

I guess you missed the part about me having a parts car sitting in the driveway. Free is always cheaper than rockauto.

Or the top of the tank cracked. When I bought Grimace, his tank had a crack in the top. Luckily I had a spare tank from a part out.....

+1 on the sending units being the same, only the pump is different.
Wagon sending units have longer steel tubes topside to reach the hoses. Sedans won't work. I learned the hard way

jayoldschool wrote:

jimbeau wrote:

Rock auto has wagon-specific assemblies. Why dick around?

I guess you missed the part about me having a parts car sitting in the driveway. Free is always cheaper than rockauto.

Uhhh, okay. I assume it's a Caddy?

jayoldschool wrote:

Yes, the Cadillac is 128B. No idea what the differences are, but I'm going to find out!

Jay:

The difference is the routing and length of the hard lines. From what I could see the assemblies are the same. Can't see why the Caddy's lines couldn't be "modified" to work. On the other hand, based on the mileage and where the Caddy came from, likely the sender on the parts car is probably no better and probably worse than the wagon.

Got the new sender for the Caddy last Fall from Rockauto for around $140.00. All attempts to marry wagon sensors, pumps etc. just cost me alot of time (tanks came down 4 times) and much aggrevation. Getting the new sensor was what I should have done in the first place. Would have saved me multiple headaches.

Bill