EVAP System Repair or Removal?

Joined
Mar 10, 2017
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1,131
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South Wales, UK
Our 97' Mini has an issue with the fuel tank.

I noticed when I filled the tank to the top I was getting a faint smell of fuel in the car which seemed to emanate from the fuel tank.

I did some rummaging about and noticed a barbed hose connector on the fuel tank to which the EVAP system connects. The seal under the barbed connector looked very perished and at the time I checked first time around, looked a bit wet...
20220812_213533.jpg


I removed the barbed connector hoping to just replace the seal but it came apparent that this barbed connector has been fitted by someone else. A quick look at a parts catalogue shows the original tank had a hose connector stamped or welded into it from the factory...
New fuel tank.jpg


The barbed connector is very badly fitted. The threads that have been put in the tank were tapped awfully, and you cannot get the connector tight without it jumping on its threads.

I've removed it, cleaned it the best I could, smeared the threads and the base of the connector in RTV and tightened it up as tight as I dare (which isn't very tight).

It seems to have solved the problem but I'm unhappy with the repair.

I'm considering 3 repair options and would like some general feedback.

1) Proper repair - replace the fuel tank. Cost ~£250

2) JB Weld a plate over the hole that has been previously made in the tank. Install a new thread in the plate and a suitably sized barbed hose connector.

3) Remove the EVAP system altogether by JB welding a plate over the hole, removing all hoses, canisters, solenoids etc and installing a vented fuel cap off a carb'd model.

To add, this car is a weekend toy that will probably do 1,000 - 2,000miles per year. It will otherwise stay in the garage. All fuel treated with Sta-bil. The ECU is non-obd compliant and the car doesn't have a CEL.
 
Joined
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14,961
Location
ROCHESTER, NY
My first view and first opinion...

1) Your repair doesn't look to awful bad and may in fact last a very long time. I'd stay with that until you need to repair it again.
2) The person who did the original repair also did a decent job that I may have done myself. 2 thumbs up to both repairs. (y) (y)

No, don't replace the fuel tank and the expensive cost. If necessary, remove and have a shop repair the tank properly if needed be.
I've removed fuel tank, HP steering lines & radiators and taken them to that specific shop for a proper repair at substantial money savings.

Again, just my first view & opinion. I may change my opinion based on more information.
 
Last edited:
Joined
Nov 20, 2006
Messages
29,237
Location
MA, Mittelfranken.de
Our 97' Mini has an issue with the fuel tank.

I noticed when I filled the tank to the top I was getting a faint smell of fuel in the car which seemed to emanate from the fuel tank.

I did some rummaging about and noticed a barbed hose connector on the fuel tank to which the EVAP system connects. The seal under the barbed connector looked very perished and at the time I checked first time around, looked a bit wet...
View attachment 117833

I removed the barbed connector hoping to just replace the seal but it came apparent that this barbed connector has been fitted by someone else. A quick look at a parts catalogue shows the original tank had a hose connector stamped or welded into it from the factory...
View attachment 117834

The barbed connector is very badly fitted. The threads that have been put in the tank were tapped awfully, and you cannot get the connector tight without it jumping on its threads.

I've removed it, cleaned it the best I could, smeared the threads and the base of the connector in RTV and tightened it up as tight as I dare (which isn't very tight).

It seems to have solved the problem but I'm unhappy with the repair.

I'm considering 3 repair options and would like some general feedback.

1) Proper repair - replace the fuel tank. Cost ~£250

2) JB Weld a plate over the hole that has been previously made in the tank. Install a new thread in the plate and a suitably sized barbed hose connector.

3) Remove the EVAP system altogether by JB welding a plate over the hole, removing all hoses, canisters, solenoids etc and installing a vented fuel cap off a carb'd model.

To add, this car is a weekend toy that will probably do 1,000 - 2,000miles per year. It will otherwise stay in the garage. All fuel treated with Sta-bil. The ECU is non-obd compliant and the car doesn't have a CEL.

What size is the fitting they put in the tank? You could replace it with a large rivet nut or a jack nut, seal it once its tight and put a threaded barb in.
 

Bailes1992

Thread starter
Joined
Mar 10, 2017
Messages
1,131
Location
South Wales, UK
My first view and first opinion...

1) Your repair doesn't look to awful bad and may in fact last a very long time. I'd stay with that until you need to repair it again.
2) The person who did the original repair also did a decent job that I may have done myself. 2 thumbs up to both repairs. (y) (y)

No, don't replace the fuel tank and the expensive cost. If necessary, remove and have a shop repair the tank properly if needed be.
I've removed fuel tank & radiators and taken them to that specific shop for a proper repair.

Again, just my first view & opinion. I may change my opinion based on more information.

The picture was how it was before I started poking around.

It looks much the same now but I've taken the seal out and put some RTV in there.

What size is the fitting they put in the tank? You could replace it with a large rivet nut or a jack nut, seal it once its tight and put a threaded barb in.

I think it's 1/4". I'll get it back out and measure it some time soon. The Rivnut idea is genius, if they do them that big?
 
Joined
Nov 20, 2006
Messages
29,237
Location
MA, Mittelfranken.de
The picture was how it was before I started poking around.

It looks much the same now but I've taken the seal out and put some RTV in there.



I think it's 1/4". I'll get it back out and measure it some time soon. The Rivnut idea is genius, if they do them that big?
Yes they do, they make them in many sizes. With flange, without flange, stainless, reg steel or aluminum.

Edit: These are some from the place I normally order them from, the L head or flat head would be my choice. These are up to 5/16 but you can get them up to 1/2 and even larger that you use a bolt and nut to instal.

 
Last edited:

D60

Joined
Nov 6, 2017
Messages
1,613
Location
Colo
I was also going to suggest a rivnut but figured the hole was too big. I've just got the Astro drill-powered tools to install them. Never seen Trav's suggested site but looks like a good resource.

I'm assuming the stated size of 1/4" in this thread is NPT/BSP? I think that's what I'm seeing in the pic? So roughly 9/16" OD?
 

LDM

Joined
Nov 8, 2018
Messages
255
Location
Illinois
Tell me more about this mod to remove the EVAP system and still not have a CEL, and presumably pass emissions???
Europe didn't require OBD2 on cars until 2001. Most OBD1 vehicles have no codes for EVAP systems as it wasn't mandated at the time.
 
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