Fuel Tank Tour

[ja17]

Hello Dan and Matt,

Good idea Dan! We'll definately keep that idea on tap.

Matt, yes the 1/2" version would work well with a  nice long breaker bar.

Joe Alexander
Blacklick, Ohio

[Vince Canepa]

For reference, my early 250SL has the flower pot with the metal lines.  I've got the tank out and examined the internals with a mirror.  The entire interior of the tank is clean and shiny - no rust and the filter screen is clear.  I really expected a little rust after all these years.

Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex

[merrill]

Joe, Dan,
well finally got the fuel tank drain plug out. I ended up using socket idea to get the plug out.  could not find a spark plug socket that would allow me to insert an extension into is to I used my metal grinder and cut the top of the socket off.  worked great.

now for the problem, the fuel that drained out of the tank was green!!  and to make things worse the tank has a lot of surface rust inside.  I need to find some one to repair the tank cause I cannot afford to buy a new one.


I believe the rust is from an aged sender gasket that allowed the  tank to breath with the external environment.  When changed there was fuel on the top of the tank.

thanks for all the help
I would appreciate any suggestions to repair the tank

Matt
Austin Texas

[ja17]

Hello Matt,

Some radiator shops will boil out the tanks. It can be cleaned with acid and recoated.  The Eastwood Co. sells kits if you wish to attempt it yourself. Most will discourage restoration of these tanks since the internal "flower pot" (thanks Dan) makes the porcedure difficult. The sealer will plug the fuel drain holes in the flower pot, the fuel  tubes and their manifold if you are not careful. The fuel manifold is the circular sheet metal housing directly around the base of the drain plug screen on the inside of the flower pot. All fuel enters the drain plug screen then the moves to the fuel manifold and exits out the internal fuel tube before leaving the tank. Return fuel from the engine enters the tank and travels down the second fuel tube before entering the "flower pot" (thanks Dan). A drain hole in the flower pot allows fuel from the tank to enter into the flower pot. This must also be kept clear.  


I suggest you study this  string carefully before attempting this. The lower manifold and the fuel tubes must be kept open. I use a old speedometer cable core and a rifle cleaning kit with brushes to clear the tubes. Streching a latex gloove finger over the drain plug screen before installing it during the coating process should keep the fuel manifold clear. Allow the tank to rest so sealer does not settle in the flower pot while the coating is drying. Clear all tubes and imposrtant openings before installation.

 
Joe Alexander
Blacklick, Ohio

[merrill]

joe,
ha ha ha ha, I just returned a tank kit to eastwood because of this thread!!!!  nuts.

before i go much further, what should I use to rinse the tank out with?  maybe there is less rust than thought and what I see if sediment on the bottom of the tank?

matt

[ja17]

Hello Matt,
After removing the fuel gauge sender, and you have removed all traces of fuel, you can clean the rust and deposites out of the tank  with a power washer or hose.  I drop an air line from my compressor into it after flushing the water out i to dry it inside.  Acid treat and coat with sealer. Having it boiled out at a radiator shop is best and safest.  


Please be sure your gas tank is drained completely and dry before cleaning it. Any contaminated fuel must be disposed of properly to protect the environment and prevent safety hazards. Gas fumes are extremely dangerous.

Keep us up to date. We need a fuel tank success story here!

Joe Alexander
Blacklick, Ohio

[JimVillers]

Matt .... One other idea that I have heard reported and should work is to boil the tank out with some caustic soda.  Fill it with water and then heat it to a roiling boil on your propane grill.  It may sound dangerous but the tank is filled with water and cleaner.

Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor

[ja17]

Hello,
Please be sure your gas tank is drained completely and dry before cleaning it. Any contaminated fuel must be disposed of properly to protect the environment and prevent safety hazards.

Joe Alexander
Blacklick, Ohio

[mille]

Hi Joe,

Very useful informations. Thank you very much.

This is what came out of the tank during the restoration work of our Pagoda. No wonder we had problems with jerky running due to insufficient gas supply. It has now been totally cleaned out and the engine runs like a sewing machine  

/Finn





Download Attachment: P8090001.JPG
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[TA250SL]

This service might be useful for anyone contemplating fuel tank repairs.

http://www.gastankrenu.com/welcome.htm

Tom
Early 1967 250SL
Euro version    
Los Angeles

[Raymond]

As someone who does a lot of environmental awareness training, it kills me to see that photo of a wet fuel tank over a floor drain.  PLEASE, PLEASE, guys, let's be environmentally responsible here.  Many times floor drains or gutters run to local waterways.  A very small amount of petroleum can pollute thousands of gallons of groundwater.

When we change the oil or other fluids, use mineral spirits to clean things, or use some of the caustic chemicals described here, we should capture as much of it as possible, label the containers as containing used product and dispose of it properly.  My city has a hazardous waste disposal location as part of the Solid Waste Department.  I collected all of the used fluids from my recent overhaul project, and also used the opportunity to get rid of some old house paint.  Check with your local government.  Most would rather have the stuff contained than worry about regulatory consequences.

Our cars are rough on the air just by the nature of their vintage technology.  We owe it to ourselves and future genterations to minimize our impact in other ways.

Thanks.

Ray
'68 280SL 4-spd Coupe

[ja17]

Hello,
Use extreme caution when dealing with gasoline. The fumes are extremely flammable. Just having exposed gasoline near an ignition source can be disastrous.

It is best to deal with it in the well ventilated outdoors. Be sure to have enough containers to cap and seal the drained fuel. Have a fire extinguisher near by. Have a method to plug or cap fuel lines and hoses.

Avoid ignition sources like trouble lights, static electric, pilot lights etc.

If you have old dry rotted fuel lines, chances are they may begin to leak or rupture when they are disturbed. Be prepared to deal with this.

Remember an empty fume filled fuel tank can also be dangerous. Work safely.

Joe Alexander
Blacklick, Ohio

[merrill]

Joe,
eastwood re-sent me a tank sealer kit today, here is a follow up question.  should I prevent the tank cleaning materials from entering the fuel lines in the tank?
I know I want to prevent the sealer from getting into the fuel lines and clogging them, however I probbly do not want to "clean" them with the chemicals either.

note: I talked to gernold at sl tech. he must just replace tanks because he did not have any recommendations on a tank restorer. he did mention tank reneu that was brought up in this list however he has no experience with them

[ja17]

Hello matt,

Before adding sealer cover the drain plug screen with something like the finger of a latex glove. Then re-install it. This will prevent most sealer from entering the fuel maifold in the bottom of the tank or clogging the fuel screen. Seal the tank as per instructions and allow the tank to dry standing on its side. If you allow the tank to rest with the bottom down you may allow sealer to settle in the bottom and clog the "flower pot" or a fue line. After coating the tank remove the fuel screen and blow air through both fuel lines. It is also a good idea to run a wire or bottle brush into the lines and then blow them clear. Small brushes and rods from a rifle cleaning kit work well. An old speedometer cable core or steel cable will also work. The thing you will not be able to access is the intake hole in the bottom of the "flower pot". This is why it is important to let the tank sealer dry with the tank resting on its side. This is why most tank restoration attemps fail. If you understand how the tank works you should succeed. Ask for more information if needed. Good luck! Remember safety when dealing with fuel and fumes!

Joe Alexander
Blacklick, Ohio

[ja17]

Matt,

Also be aware of the tiny vent line which snakes along the top of the gas tank and originates in the filler neck. Blow this line clear during the sealing process. This allows the tank to "breath" during fill-ups. If clogged you will have trouble adding fuel during fill-ups.

Download Attachment: gas tank internal vent line illus.JPG
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Joe Alexander
Blacklick, Ohio

[J. Huber]

Guys. At what point would an owner want to check the drain plug/ fuel screen? In other words, is this a preventative maintenance thing? Or only when there is a fuel delivery prob? And I am assuming this is done near empty with a big old bucket underneath? Just curious.

James
63 230SL

[Naj ✝︎]

Hey, James,
I think its worth a look if its not been done whilst in your possession.
Here's what I did:
Run the tank down as low as possible - long after the red light's come on.
Have container ready. Disconnect feed line to engine from the electric fuel pump and connect another hose to allow draining into container. Switch on ign to operate pump and let drain completely.
Clean the filter in the fuel pump inlet while you're down here.

 Usual warnings apply when playing with fuel!!

I was lucky to have a rebuilt pump when I did this job. I used it to pump the fuel back thru the return pipe into the flower pot. about 4 litres was enough to get me to the nearest gas station. [:p]

naj

65 230SL
68 280SL

[J. Huber]

Thanks Naj. Well, I'd have to say, it probably has been done during my ownership -- just not by me. I had the tank out when it busted a seam -- they sent it to the radiator guy who welded it and gave it the once over. New plumbing, gasket for sending unit, etc. I'd bet the screen was tended to then. 4 years back.

James
63 230SL

[merrill]

Joe,
can i remove the fuel tank without placing the car on a lift?
It appears that the fuel neck will clear the hole in the rear with out any real problems.

also,  I have removed the cover for the filler neck and noticed that the vent lines were junk.  everyone should check their vent ilnes !!

 between the vent lines and the dried up sender gasket I am not suprised that the tank has corrosion.

thx
matt

[rwmastel]

quote:Originally posted by merrill

Can i remove the fuel tank without placing the car on a lift?

I have done it on my 230SL.  I believe I did use two standard jack stands to keep the rear up.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[merrill]

Rodd, Joe,
I was able to get the tank out of my 66.  I had to remove the 3 rubber mounts for the exhaust as the passenger front corner of the tank was blocked by the exhaust system.

also, some ding dong used a large washer on the front mount of the tank so it was restricted by the center axle spring.  needless to say, it was not too hard, just supported the tank with a floor jack with a small 2x4 buffer, unbolted it and then let it down.  I sure hope it goes back in as easy.

any way, flushed the tank out with water, and filtered it and found mud. I could not even see the filter thru the red mud.  after two flushes the water was clear.

now, on to a question, I have been thinking about the sealing process for the tank.  I am probably going to try to cap the flower pot with a cover from a small ice cream container or something to keep the sealer from going into the pot.  

I also thought of getting some small catheters from a medical supply store to insert into the tubes then inflate inside the very end of the tubes to keep the sealer out.  Still have to let the tank seal with the flower pot upside down to keep the sealer out - just in case.

now all i need is a rear axle and brake tour and I will have more projects than I want.

I will post my results once the sealing is complete.

matt

[lurtch]

One more note should be added here somewhere - - -

No tour of our fuel tank woes is complete until  we have all seen the worst - - - This jpg. shows it!   My tank had about two gallons of PUTRID five-year-old gas in it.  Along with enough rusty sediment and gummy failed sealer residue to fill a coffee cup.

The previously mentioned "gastankrenu.com" did the work on mine. Very reasonably priced and an excellent job.

Regards. Larry in CA

Download Attachment: tank-holes.jpg
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[merrill]

Joe,
one more question, after reviewing the photos of the flower pot, how does the fuel get into it?
are there openings at the base that allow fuel in?  
otherwise the fuel must flow over the top of the pot?

thanks
matt

[ja17]

Hello Matt,
Yes there is an opening at the bottom of the flower pot, just under the fuel return line. It allows the fuel to flow into the flower pot.



Joe Alexander
Blacklick, Ohio

[merrill]

Joe & everyone,
well finished my fuel tank seal project.  looks to be a success, for anyone that my try to seal their tank in the future here is a recap of my experience.

1. study the fuel tank tour thread, understand that the fuel inlet into the flower pot is below the return line.

2. read and re read the instructions on the seal kit. I used the tank seal kit from the eastwood company.  I had to call them to verify the instructions.  The east wood kit calls for you to buy an additional 2 quarts of acetone ( buy two one quart cans) and muriatic acid. The acid is used during the prep process, the dilution is 20:1 water to acid mix.  1/2 gallon.


3. pull and cover the fuel tank screen, I used a finger from a latex glove and then some electrical tape wrapped around to seal it well.

4. make a cover for the sender unit opening, I used a plastic ice cream top, cut and drilled using the gasket from the sender unit as a template.

5. have covers for the fuel return and feed line. I had vacuum covers from a mighty vac kit that fit well.

6. the main catch to sealing the tank is to follow the instructions, and when sealing the tank to not clog any of the fuel lines.

have heavy plastic gloves and a face protection. the chemicals used are nasty, if you have a respirator use it.

When it came time to apply the sealer, with the help of the mrs I coated the sides of the tank, then did the bottom of the tank.
to keep the sealer out of the fuel inlet in the flower pot, I removed the cover for the sender unit so I could see the bottom of the tank , then with the tank standing up, we slowly lowered the tank bottom side down and I watched the sealer as it flowed toward to flower pot, once it was approaching the inlet, we raised the tank just a little and allowed the sealer to just touch the bottom of the flower pot. we did the 2x, then angled the tank around to get the sealer on the other side of the flower pot to cover the rest of the bottom of the tank.

re-install the home make sending unit cover, turn the tank over and seal the top of the tank.

per the instructions after waiting 8 - 10 minutes, drain off the excess sealant.  

Use compressed air to verify the fuel feed and return lines are clear, also check the vent lines.  I used an extra guitar string to verify the vent lines were clear.  Using the process above I was not too worried about the fuel inlet and return lines being clogged as I never got sealant in the flower pot.

once the sealant has cured I will verify the flower pot fuel inlet is clear.  probably will use some clear poly line placed into the flower pot and allow some water flow thru the tube to the inlet hole and verify by viewing the fluid flowing out of the flower pot.

the whole process took about 2 hours, and is an inexpenisve route to attempting a do it your self tank sealing.  the eastwood kit was about $50, muriatice acid and 2 qts of acetone was about $10.

This is a lot less than buying a new tank from mb or a repro from k&K - as long as it works.

anyway, hope this info helps anyone that may be thinking of sealing their own tank.