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Fuel tank cleaning

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Hi all just starting out and new here,

i have just pulled out my mk1 1.8 gti from 17 years of storage. I'm in the process of trying to get her running I have had to get a new fuel pump so I wanted to check out the condition of the tank before putting in the new pump it's not great. Just wondering about trying to wash /flush it out in place I don't want to have to take it out if I can avoid is there a solution I could use I've heard people using vinegar to clean out fuel tanks. I thought maybe of getting a drill pump to wash / flush a solution through it. Any advice would be great.

Cheers.

 

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I checked my with a magnet through the sender opening looking for rust.

I used a telescopic pen type magnet as it reached all corners.

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I checked mine with a magnet through the sender opening looking for rust.

I used a telescopic pen type magnet as it reached all corners.

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Yeah I was going to do that but what about a wash or a flush ?

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Jemmer40 said

Yeah I was going to do that but what about a wash or a flush ?


The problem is the dirt/rust bits don't tend to stay suspended in whatever you use to wash it with. The best way is to bite the bullet and remove the fuel tank, then you can get it properly sorted out by repeatedly washing it out, shaking it around and pouring the fuel/dirt out through the big openings.

                                

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Yeah I was thinking that. Is it a big deal getting the tank out I know there's 2 straps I still have the pump out so that's 1 less disconnection

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I guess it depends how bad it is. If its really bad, like they can be, then there's no pragmatic option other than to remove the tank and properly clean it out - which might involve repairing/painting the tank again, and/or doing some kind of coating on the inside too. I remember in the past, dubboy arranging for some kind of rubberised fuel-resistant paint coating, for a proper job.

But if it wasn't too bad then trying with a magnet or other pickup tool of some kind through the top access, or simply carefully checking the fuel filter and replacing it if it gets clogged, may suffice. I'd say if the car's been in storage for 17 years then other components too, are affected, so you might need to eg remove the rear axle and fuel tank to do welding repairs in the local area, or it needs new brake lines anyway (unless good condition, these will probably break or snap at the connections, rather than being able to undo then reuse the same connectors).

                                

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Thanks paul c

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Would you take the chance ?? This is the best pictures I could get

image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg

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Would you take the chance ?? This is the best pictures I could get

image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg

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Normally rust is the issue but that looks different - it looks like the gummed-up residue from old petrol. If it is that, then its going to be constantly producing bits of jelly held in suspension with the petrol, for weeks/months of running. So I'd be tempted to try and clean it out. As far as rust goes, I can't see much (any) so you may be okay there. The best thing to clean it out is probably petrol anyway (and this also much simplifies things) but you'd need to get some kind of cloth that doesn't dissolve in the fuel to physically wipe the tank inside surface clean. I suspect this would be easier with the tank out but might not be too hard with it in.

                                

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Over here the old days, folks would remove the tanks and take them to a radiator shop and have them boiled out.  The Pressure tested and repaired.  I think it was 30 bucks when I had my MG's tank repaired, it was sitting for a while and well…… It was a hole lot easier as I had to remove the sender and repair it, so at the time I thought to take it and have it cleaned.  There were a couple of pin hole leaks that were repaired as well.

Now it is almost cheaper to drop in a new tank.  Be sure that if you drop it, clean the Axle bolts for rust hit them with a brush then pb-blaster for a few days, and use air impact to lessen the chance of torque shearing the bolts.  You have to lower the axle so take care to be mindful of the rubber Brake likes and it wouldn't hurt to order a set… Old rubber doesn't like to move about a bit.


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They all start with GOOD Grounds.

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Briano1234 said

Over here the old days, folks would remove the tanks and take them to a radiator shop and have them boiled out.  The Pressure tested and repaired.  I think it was 30 bucks when I had my MG's tank repaired, it was sitting for a while and well…… It was a hole lot easier as I had to remove the sender and repair it, so at the time I thought to take it and have it cleaned.  There were a couple of pin hole leaks that were repaired as well.

Now it is almost cheaper to drop in a new tank.  Be sure that if you drop it, clean the Axle bolts for rust hit them with a brush then pb-blaster for a few days, and use air impact to lessen the chance of torque shearing the bolts.  You have to lower the axle so take care to be mindful of the rubber Brake likes and it wouldn't hurt to order a set… Old rubber doesn't like to move about a bit.



Yeah but I've also heard that the "new" tanks aren't the same quality as an original VW one. Back when I did mine, I searched around for a decent secondhand genuine one, and it wasn't massively hard to find (but was quite hard to find postage for it!) I don't know who now sells new tanks, or their price or quality though.

                                

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paul_c said

Briano1234 said

Over here the old days, folks would remove the tanks and take them to a radiator shop and have them boiled out.  The Pressure tested and repaired.  I think it was 30 bucks when I had my MG's tank repaired, it was sitting for a while and well…… It was a hole lot easier as I had to remove the sender and repair it, so at the time I thought to take it and have it cleaned.  There were a couple of pin hole leaks that were repaired as well.

Now it is almost cheaper to drop in a new tank.  Be sure that if you drop it, clean the Axle bolts for rust hit them with a brush then pb-blaster for a few days, and use air impact to lessen the chance of torque shearing the bolts.  You have to lower the axle so take care to be mindful of the rubber Brake likes and it wouldn't hurt to order a set… Old rubber doesn't like to move about a bit.



Yeah but I've also heard that the "new" tanks aren't the same quality as an original VW one. Back when I did mine, I searched around for a decent secondhand genuine one, and it wasn't massively hard to find (but was quite hard to find postage for it!) I don't know who now sells new tanks, or their price or quality though.



I replaced my tank this year with a pattern item from vw heritage. I was made aware of the issues by other forum members at the time when I was pulling mine apart. I have to say, while I agree that the swirl chamber looks no where near as good as the genuine item, I have now used two tanks of fuel and had no problems. Both times I filled up with about 32 litres so less the 1/4 tank left. Maybe I was lucky with my tank or maybe I will have problems in the future! My car had stood for 8 years with water in the fuel and had loads of tiny pin holes in it. The fuel wasn't leaking out but there was bubbles in the paint and if you rubbed your hand over them they had fuel in them!
With regards to dropping your axle, as said before, loads of penetrating oil, wire brush the threads until clean, more oil and careful undoing 1/4 turn, doing back up, more oil and cleaning and so on. Be very patient with them. I had to cut my flexi hoses off as I couldn't undo them and I replaced all of the brake pipes on and around the rear axle. I also ended up doing a fair bit of welding while the tank was out (I wasn't expecting it and did start wishing I hadn't bought the damn car). Prepare to replace the fuel pump while it's all apart, I didn't and had to drain the tank again to fit a new pump! Good luck!

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Cheers guys and thanks for all the advice.

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Ok update
Got onto a company today that pump's out fuel when people make the mistake of putting the wrong fuel in a car. Sent him on the pics he seemed to know his stuff so what he recommended put in cider vinegar and leave for a day or two then he can pump everything out dry and after that he pump' s gallons and gallons of unleaded in and out of the tank he also said he can flush out the fuel line. Thinking strongly of going down this road it's a little expensive Apple vinegar €16 for 5lt.

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Here a solution that Bert uses and I can endorse for getting rust out of a tank…

Start with a car battery, connect a fuel pump to it and attach 2 lengths of pipe, connect a fuel filter to one pipe and another piece of pipe out of the filter. 

One end of the pipe goes into the tank to 'Hoover' debris out while the other end of the pipe goes back into the filler neck to recirculate the filtered fuel - minus the debris. 

I did mine back in 2013 and got this lot out of the tank!!! 

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Here's a solution that Bert uses and I can endorse for getting rust out of a tank…

Start with a car battery, connect a fuel pump to it and attach 2 lengths of pipe, connect a fuel filter to one pipe and another piece of pipe out of the filter. 

One end of the pipe goes into the tank to 'Hoover' debris out while the other end of the pipe goes back into the filler neck to recirculate the filtered fuel - minus the debris. 

I did mine back in 2013 and got this lot out of the tank!!!

  image.jpeg

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I think I'm getting there !!! image.jpeg

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I should of listened to paul c
I think the only way is a new tank got the car running runs well and sounds good but after a couple of days my brand new fuel pump started making a noise. 😡 I think I'll be able to save it but anyone trying to clean a tank in place forget about it.
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