Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG. This site is not affiliated with Porsche in any way.
Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners.
 

Welcome Guest ( Log In | Register )

> Fuel Tank Prep for Install, Should I Pressure Test It
DennisV
post Aug 17 2025, 08:17 AM
Post #1


Senior Member
***

Group: Members
Posts: 682
Joined: 8-August 20
From: Santa Rosa, CA
Member No.: 24,575
Region Association: Northern California



I'm planning to refurb our fuel tank this trip. Should a fuel tank be pressure tested? If so, how the heck do I do that? This is a 914-6 carburetor car, if it matters.

It is out of the car and appears to be in very good shape. It hasn't had anything in it for many years. I would love to think there is some high tech copper coating in the bottom, but I suspect that is surface rust. I am thinking that a couple gallons of Evapo-rust for a few days will solve that. Also provide some evidence if there are major leaks. Then probably fog it with Sea Foam, since it will probably be months before it's actually attached to the engine.

Anything I'm missing before it would go back in the car?

Attached Image
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
 
Reply to this topicStart new topic
Replies
Montreal914
post Aug 17 2025, 10:22 AM
Post #2


Senior Member
***

Group: Members
Posts: 1,898
Joined: 8-August 10
From: Claremont, CA
Member No.: 12,023
Region Association: Southern California



Could it be just old fuel varnish? Seems a bit shiny for being rust.

Tank looks very clean otherwise. I would replace the sock at the fuel line pickup.
User is online!Profile CardPM
Go to the top of the page
+Quote Post
fiacra
post Aug 17 2025, 02:56 PM
Post #3


Person.Woman.Man.Camera.TV
***

Group: Members
Posts: 596
Joined: 1-March 19
From: East Bay Region - California
Member No.: 22,920
Region Association: Northern California



QUOTE(Montreal914 @ Aug 17 2025, 09:22 AM) *

Could it be just old fuel varnish? Seems a bit shiny for being rust.

Tank looks very clean otherwise. I would replace the sock at the fuel line pickup.

(IMG:style_emoticons/default/agree.gif) Just looks like varnish. From what I can see I would simply clean it with Por15 cleaner/degreaser. I only needed a quart (link below). I did that with my Super Beetle tank that had been sitting for 16 years. It looked in similar condition to yours (again, from what I can see) and it cleaned up just fine. I wouldn't clean the tank until just before you are ready to install it and put fuel in it. If it sits for a while you could get light surface rust. If it is going to sit for a while make sure you seal the openings well and keep it in a warm dry place. After cleaning I used a hair dryer to make sure the inside of the tank was as dry as possible. There are more than a few videos about this on-line, some good, some done by idiots. You'll quickly figure out which is which (I woudn't, as an example, dump out the cleaner on my front lawn when I'm done).

https://por15.com/products/cleaner-degrease...Z4jySTdOJuFFBmb
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
DennisV
post Aug 17 2025, 04:14 PM
Post #4


Senior Member
***

Group: Members
Posts: 682
Joined: 8-August 20
From: Santa Rosa, CA
Member No.: 24,575
Region Association: Northern California



QUOTE(fiacra @ Aug 17 2025, 01:56 PM) *

Just looks like varnish. From what I can see I would simply clean it with Por15 cleaner/degreaser. I only needed a quart (link below). I did that with my Super Beetle tank that had been sitting for 16 years. It looked in similar condition to yours (again, from what I can see) and it cleaned up just fine.

Thanks for the suggestion. POR-15 will clean varnish? I am not seeing that application in the product description, but it sounds like you have first hand experience. Did you dilute it? They are saying "can be diluted with water up to 4 to 10 times its volume".

Thank you.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
fiacra
post Aug 17 2025, 04:45 PM
Post #5


Person.Woman.Man.Camera.TV
***

Group: Members
Posts: 596
Joined: 1-March 19
From: East Bay Region - California
Member No.: 22,920
Region Association: Northern California



QUOTE(DennisV @ Aug 17 2025, 03:14 PM) *

QUOTE(fiacra @ Aug 17 2025, 01:56 PM) *

Just looks like varnish. From what I can see I would simply clean it with Por15 cleaner/degreaser. I only needed a quart (link below). I did that with my Super Beetle tank that had been sitting for 16 years. It looked in similar condition to yours (again, from what I can see) and it cleaned up just fine.

Thanks for the suggestion. POR-15 will clean varnish? I am not seeing that application in the product description, but it sounds like you have first hand experience. Did you dilute it? They are saying "can be diluted with water up to 4 to 10 times its volume".

Thank you.


Says right on the front of the container that you can use it to clean fuel tanks. It definitely cleaned the old varnished fuel out of my SB gas tank. I did use some loose chain on the inside to help clean while I was agitating it. Some people use washers or screws, but I was afraid I wouldn't get them all back out again. I diluted it with hot water about 4-5:1. You can do use a less dilute concentration if your tank needs it. Mine was worse than yours and it only took one bottle. Can't remember how long I turned and agitated the tank for, but I do recall how tired my arms were afterwards. I think I just bought a set of stoppers on Amazon to seal the openings in the tank while I cleaned it. Search for some videos, they will be helpful. Here's a link for one as an example. This is just from a quick search.

https://www.youtube.com/watch?v=2JoHRfmrTes

NB: I strongly recommend using proper protective gear such as safety glasses, gloves, etc. At least he wasn't wearing flip-flops!

Just to be clear, I'm not recommending the full POR 15 fuel tank "restoration" kit. Plenty of well documented examples of the sealer failing and then clogging the fuel system. I'm just recommending the cleaner, and not the etcher and sealer. You can buy the cleaner separately.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post

Posts in this topic


Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



- Lo-Fi Version Time is now: 22nd August 2025 - 08:08 PM