Thought it was going to be a relatively quick job....Pep Boys had a replacement pump for my tired '85 coupe in stock yesterday, and I was ready to get the car running today.....boy was I wrong

I should have known better when I noticed that one of the nine 10 mm bolts holding the tank filler neck assy. was missing...broken off from a previous owner. Well 4 of the remaining 8 bolts were broken off by me today...all near the lower aft portion of the assy where any moisture would collect over the years. So now I expect to have to drain and remove the tank to attemp to get the 5 broken bolts removed, before a worst case of replaciong the tank.

Also found entire filler neck/fuel pump bracket & line assy was severly corroded inside tank. I guess I will just clean off all corrosion as best as I can before re-inserting it in the tank with new pump. Any body know of any fuel resistant paint or treatment that should be used once the corrosion is removed?

I'm also looking into the tank and finding another reason to remove tank...corrosion debris from the corroded tank filler neck/pump brack & fuel lines. Need to get all of that crap out of the tank before installing a new pump.

 

Do you have the pump and sending unit assembly removed now?

 

Yes, the assembly was already out when I posted...that's how I saw all of the corrosion on the parts that are normally inside the tank.

 

I just finished my tank corrosion problem on my 85. Mine was so bad I replaced the entire pump, sending unit and filler tube. I checked all the web sites and found the best deal from corvettepartsman.com $239.00. You do not want to remove the tank. I tried and decided to do my repairs with the tank in place. In order to remove the tank you have to remove the rear frame, exhaust and rear bumper panels. Without a hoist thats almost impossible. With the tank fill assembly removed you have enough access that you can put your arm in there. The tank has a liner and is pretty well protected. If you soak the bolts overnight with penetrating oil, WD40 or the likes, they will be easier to remove. You can drill a small hole in the bolt large enough to get an easy out in there to remove the broken bolt. The only problem is you can't make a spark while drilling and the bolts do not go all the way thru into the tank. I drained my tank from the top with a syphon pump I got from the auto parts store and flushed the tank out about 3 times with water to de gas the tank. My tank was all dirty and I got it to the point that I used a SHOP VAC to suck out the dirty water. Also A new tank costs about $800.

 

Thanks for the info. I'll probably take my time to work these fuel tank bolt problems ...as this is not my primary or even secondary vehicle.

-dave