Pulling Fuel Tank

Hugh R · 12-01-2003, 08:24 PM

I checked the threads and didn't find an exact match. I think I have a lot of crap in my fuel tank and want to pull it and slosh it out to get all the junk out of it (car runs like crap, new fuel filter runs OK, several times in a few thousand miles per filter) Is it a big deal? Any thoughts would be greatly appreciated.

Bob's Flat-Six · Bob's Flat-Six's Garage

Hi Hugh,
You want clean fuel that's forsure. Are you saying that you keep changing filters because their getting clogged up? And if so how did the tank get dirty? did the car sit a long time with old gas?

Zendalar · 12-02-2003, 02:27 AM

I cut it open with a saw, sandblasted it, re-welded. Like new now.

Mike Kast · Mike Kast's Garage

I think if I do it again it will be a radiator shop job. Are you asking how to remove the tank? And what parts to buy if you do?

nick-moss · nick-moss's Garage

I took the tank out of my 68 recently.

Make sure you have a large enough container to drain the fuel into before you pull the plug! Take off the the supply and return lines, undo the three fixings in the trunk, the sender wiring, breather pipe and filler pipe. The tank should pull straight out now, although it may be stuck to the foam seal. It helps to break the seal with a trolley jack under the tank, suitably protecting the tank with a sheet of ply.

Use POR15 tank cleaner, rust preventer and sealer, it takes several days to do this properly.

I would clean out all the fuel lines while you are at it and change the fuel filter.

Good luck

Shuie · 12-02-2003, 04:34 AM

Pull the fuel sender and shine a light down in the tank. You should be able to see any sediment or rust. If you dont see anything then leave it in the car.

Hugh R · 12-02-2003, 06:57 AM

Thanks for all the great advise. Shuie, I like the idea of pulling the fuel sender first. I'll try that first. I don't know the history of the car, just that it bogs down, especially when low on fuel, and seems to run better with a 1/2 full tank or more and a clean fuel filter.

Hugh R · 12-02-2003, 08:33 AM

Another question:

I noticed in the PP catalogue that there is a screen in the bottom of the fuel tank is this worth pulling? Tank empty of course.

vash · vash's Garage

my screen part was attached to the plug. if you have alot of fuel in the tank, siphon first. my tank was gross, it jacked my car up. (dont get me started...) i couldnt find a container suitable to fit under the car and hold the potential volume my mystery fuel gauge stated was in the thing. definately siphon 1st. so if you want to clean the screen, and you should, that plug is going to have to come out. i paid $175 to a radiator shop for a good cleaning and coating. by the way, the plug is one of those wonderful b.a.f.a. (big A$$ friggen allens) that porsche engineers loves to make us keep in the tool box. i made one with a suitable bolt and double nuts.

cliff

Kevin Taylor · Kevin Taylor's Garage

Just did this last weekend. Do disconnect battery.
Don't assume looking into the tank will tell you how
dirty it is. Pull it. Add another in-line filter up front.
Change filter in rear.
Mine had at least a quart of water in it.
Everytime I went up or down a hill it would stop.
I looked into it with flash lite and could not see it.
Drain it. Pull it.
Get some cleaner....pour it in and shake tank back and fourth
repeat several times. I used paint thinner and a couple plastic bottels of alcohol for final rinse. I also blew lines out with small air pump I had sitting around. What a difference it made.....filled with ten gallons
of fresh gas...heet...techron and blast off. Good luck.
Keep garage door down so the fumes don't go and pay a visit with
your hot water tank.
K.T. 1973 911E 2.4 MFI

DavidI · 12-02-2003, 01:56 PM

I agree with Kevin. I had a 67 912 that had a gummed up fuel tank.

You should drain the tank and remove it. You can take out the sending unit (a few screws and a gasket) being carefull not to bend the float linkage. There are 3 or 4 allen bolts holding triangular retaining pieces around the tank. At the bottom of the tank you can remove the drain plug which should have a screen in it.

I found a radiator shop in Ontario CA that cleaned gas tanks and resealed the inside for $125. It took about 3 days.

I bought a new drain plug and screen from the Porsche dealer for $45.

It solved the problem! Good luck, David

Mike Kast · Mike Kast's Garage

. I was told the POR15 sealer is no good for the tanks with the plastic baffle. I just used the POR15 cleaner and left it at that. It made sense that the POR15 wouldn't adhere properly to the plastic and might come off in the tank and cause a whole nother list of problems. I think it is worth doing. Do a search, there is a thread in here with a good step by step. You also have to disconnect the filler tube and slide the tank out like a puzzle. Where talking about an 84? Mine is an SC so I don't know what the differences in tank designs are between the years. There may be none, I don't know. I didn't see a whole lot of gunk looking through the hole in the top either but I had a half gallon of nastyness in there. Looked like italian salad dressing. If you search salad dressing you will find my thread on it.

Randy Webb · 12-02-2003, 03:38 PM

"pulling the fuel sender first" -- you can see some parts of the tank if you do this but not all. I used a fiber light and swivel mirror and could see most of it. If the filters are getting gummed up you'll need to pull the tank.

If your wife is specializes in internal medicine you can use her fiber endoscope which will work great. Just don't tell he you borrowed it....

David · David's Garage

In case this hasn't been said enough, you must remove the drain plug and filter and clean it. A 7/8" allen wrench will fit it.

I finally gave up and pulled the tank out of the evil SC that I've been working on for almost a year (it was parked for almost 7). I probably got 2 cups of rust out of it before the big pieces stopped coming out. I sent it to Moyer's in PA. $325 to restore it, lifetime guarantee.

Mike Kast · Mike Kast's Garage

Quote:

$325 to restore it, lifetime guarantee.

What does the restoration consist of? Will the cut it in half?

Rustbucket · 12-03-2003, 09:21 AM

Here is the link to Moyer's.
Haven't used them, but heard good things about them.

gas tanks

David · David's Garage

They said on the 911 tank they usually cut out the tire bump and go in from there to grit blast clean it, then weld it back together, coat the inside then the outside. When I was searching for options, everything seemed to point back to Moyers.

Oldporsche · 12-06-2003, 06:26 AM

My plug was a 19mm hex recess. I used a long bolt with a 3/4" head on it. I heated the shank of the bolt and bent it at a right angle very close to the head. This gave me a wrench that I could use. I have since modified it by cutting off the bolt and welding a nut to the threaded end. This lets me use the socket wrench for removing that plug.

David Duffield