e34 Fuel Tank Repair

[Derek A.]

Had anyone taken their tank into a radiator shop and had it reconditioned?

Or maybe tried this from the por-15 people?
http://www.por15.com/prodinfo.asp?grp=FTRK&dept=12

I need to drop the tank this weekend and figure out a plan of action if I find a hole in it.

[Winkie]

Had anyone taken their tank into a radiator shop and had it reconditioned?

Or maybe tried this from the por-15 people?
http://www.por15.com/prodinfo.asp?grp=FTRK&dept=12

I need to drop the tank this weekend and figure out a plan of action if I find a hole in it.

I have had mine welded
you empty the tank of all fuel the put a pipe in it from the exhaust of a running car for about 15 mins before welding this gets rid of any danger from fuel vapour etc

[5mall5nail5]

Do you suspect a hole? Is it rusty inside? Whats the deal? Honestly, you're best getting another tank. I welded mine as well just wash it out really well.

[Blitzkrieg Bob]

Had anyone taken their tank into a radiator shop and had it reconditioned?

Or maybe tried this from the por-15 people?
http://www.por15.com/prodinfo.asp?grp=FTRK&dept=12

I need to drop the tank this weekend and figure out a plan of action if I find a hole in it.

I have used lining kits before.

It's a lot of work sloshing the tank around for hours.

I'd look for a replacement, since there are plenty of E34 parts cars around

[attack eagle]

if you are welding, you can just back purge it with whichever inert gas you are using for welding Seems much simpler than running exhaust into it to do the same thing

[HausBimmer]

I'd just get one from a junkyard - I know you are in Michigan, but I still don't think a rusted out fuel tank is common.

[BavarianFanatic]

Rusted/leaking tanks on E34s are actually more common than you realize. Same for the tank straps. I wouldn't even consider used. I've always replaced mine with new. Not that terribly expensive if I remember correctly. Around $200 or so...

[Derek A.]

Real Oem has the tank listed at $469.84.

Everytime I fill up I smell gas until I get below half a tank. Replaced all the overflow lines, there is still something weeping. Until I get it dropped I won't know for sure. the POR-15 stuff is like $50, local guy wants $250 to treat it and a new tank is expensive.

I could go the salvage yard routine - concerned that I would end up with the same thing. Will see what happens when I get the tank down.

[Binjammin]

To inert the tank the easiest way is to (obviously) remove the fuel pump and fill the tank with water. Clean the paint off the area you suspect of leaking, and you'll see a wet spot form from the water. If it's just simple pitting holes you can use a torch to heat the tank and a brass brazing rod to fill the hole. You'll need to drain the water before brazing, and fill it again to check afterwards. If the seam of the tank is leaking because it's rusted in between the tank halves... well you're probably hosed. Time to pick up another tank.

[Derek A.]

I ended up pulling the tank. Found a minor crack in the top of it that was letting fuel out. It wasn't very voluminous but certainly did smell. I used JB weld to patch it(see the grey spot on the lower flat portion). Went over the whole tank with rust-conversion paint and finished it up with a fresh coat of rustoleum. Total cost $25. Filled it up last night, hopefully will take care of the tank for a few years.

[Binjammin]

Be prepared to find the JB Weld won't fix it for more than a few weeks. I don't mean to crap on you trying it, but the tank will flex while the JB Weld won't, eventualy it will just work the crack back open. Good luck with the car!

[Derek A.]

I don't think the original problem was as a result of the metal flexing. I am guessing that it was an area where the coating on the tank was thinner and the area rusted - near a point where the metal was thinned out when it was pressed. I did a JB weld repair on my e28 tank it help up for a long time - we'll see what happens

[spikesamuels]

Hello, I thought since you have gone thru this perhaps you can answer a question for me - I've got a rusted and one broke tank straps - can I get to the front bolts without removing the tank in order to replace the straps?

[Derek A.]

There are no bolts at the front. The strap is curved and it hooks into a spot in the front. You just need to undo the bolts at the back, and its a lot easier to do if the rear bumper is off.

[jbondbmw]

I ended up pulling the tank. Found a minor crack in the top of it that was letting fuel out. It wasn't very voluminous but certainly did smell. I used JB weld to patch it(see the grey spot on the lower flat portion). Went over the whole tank with rust-conversion paint and finished it up with a fresh coat of rustoleum. Total cost $25. Filled it up last night, hopefully will take care of the tank for a few years.

Interesting repair. I wish I could fix mine for $25. Mine is rusting along the seam behind the passenger side tank strap.

[Derek A.]

The repair didn't hold but two weeks. I ended up just replacing it with a new tank.

[Big Lou]

I have a fuel leak I have a 1993 525 estate with a plastic tank. I inspected all pipework at last mot and they are all ok. I am going to drop the tank and hopefully repair the tank with some tank repair stuff I found on eBay renew fuel filter and rubber pipes. I currently can only put £20 in the tank and my fuel guage never worked with low fuel. I will update when completed.

[jehu]

hit a deer last night and apparently some of the shock from impact caused a leak in the fuel tank.... came to check this idea.... new tanks are over $1,500 now... last time I bought a new tank was 2014 for $550.