Vw t25 1984 fuel tank problem

[colincolin64]

Hi there guys help needed please wen I fill up with fuel is it right or not the fuel comes out of the top of the tank underneath. Instead I am waiting for the nozzle to click to tell me I am brimmed . I put a new sender in and seal a bit back and all was fine . Av I done something wrong or is pipe work come loose I Thort it went in to the expansion tanks or is that wrong aswell thankyou colin sorry for daft question but got me baffled cheers

[Smcknighty]

Shouldn't happen, likely breather hoses have perished

[Mojoh]

Greetings. Gonna poke my nose in here!.... This has got to be the most annoying problem when you are new to the T3/T25. There are several reasons for this happening and indeed as said already the top-of-tank breathers are normally guilty. We've got 6 T3's, and we've re-piped them all...., but it's a quite a job to do it properly. You have to take the whole tank out to do the job once and for all....

Here's a short version of the real thing.

Drive the van to empty.... I mean down to the last drop.
Jack up the front and support on axle stands. (high).
Both Front Wheels off.
Remove Filler cap, three screws and release filler neck... (by drivers door if you are RHD??)
Get under, release two small 8mm pipes, one feed, one return on back of tank.
Undo the two straps that support the tank and start to lower carefully.
(a bit of twisting and turning, but it will drop perfectly).
Release upper breather pipes & fuel guage level cable (top left of tank).
Remove tank to bench.

You have a network of small pipes.... from left to right, right to right and left to left.
There is a larger bridge pipe, left to right which sits above the handbrake cable.
This MUST be in good condition and put back in when the tank is all but back in place.
It's all a bit like spagetti junction, but actually fairly simple once you work out which pipe goes where.
I'd recommend cleaning the tank, painting it and then reassembling it with all new rubber pipes, clips and as said earlier, making sure the cross pipe is correctly fitted. You have to replace the 'bungs' in the top of the fuel tank, three of them. We assemble it all with light LM grease to make the final fit eaier. Small hands will help!!!!!

We allow four hours to do this job, excluding paint drying time. You only need to do this job once in the life of your van, but almost everyone who is new to T3 gets this rather smelly and shocking problem. This is our love affair.

Good luck...... Mojoh

[Smosh]

Half way through doing this task myself. I have the tank down and benched anyway. It's not too hard to get the tank out, but my hoses were very badly perished! I got to say, I'm not looking forward to reassembly!

[Mojoh]

Reassembly is straight forward as I said.
Bear in mind a few things.

Put the three bungs in before putting the tank in.
Have the Cross Pipe (over the handbrake cable) back in place and clipped to body upper.
(these clips rust away, so you might have to replace it).
Connect the smaller rubber pipes to the rear pipes of the upper tank.
Leave plenty of slack on pipes to cut them exactly to length once tank is back in place.
When you put the tank up finally, DON"T FORGET THE FUEL GUAGE SENDER CABLE!!!!!
Don't forget the other ends of the smaller pipes, which all join up to those expansion tanks which sit
under the wheel arches. One on each side. Two pipes on each.

We fit Wheel Arch Inner Guards to all our vans (plastic). Great for keeping these areas away from mud/road grime,
stops ¼ post rust problems too.

[Fudgy666]

Greetings. Gonna poke my nose in here!.... This has got to be the most annoying problem when you are new to the T3/T25. There are several reasons for this happening and indeed as said already the top-of-tank breathers are normally guilty. We've got 6 T3's, and we've re-piped them all...., but it's a quite a job to do it properly. You have to take the whole tank out to do the job once and for all....

Here's a short version of the real thing.

Drive the van to empty.... I mean down to the last drop.
Jack up the front and support on axle stands. (high).
Both Front Wheels off.
Remove Filler cap, three screws and release filler neck... (by drivers door if you are RHD??)
Get under, release two small 8mm pipes, one feed, one return on back of tank.
Undo the two straps that support the tank and start to lower carefully.
(a bit of twisting and turning, but it will drop perfectly).
Release upper breather pipes & fuel guage level cable (top left of tank).
Remove tank to bench.

You have a network of small pipes.... from left to right, right to right and left to left.
There is a larger bridge pipe, left to right which sits above the handbrake cable.
This MUST be in good condition and put back in when the tank is all but back in place.
It's all a bit like spagetti junction, but actually fairly simple once you work out which pipe goes where.
I'd recommend cleaning the tank, painting it and then reassembling it with all new rubber pipes, clips and as said earlier, making sure the cross pipe is correctly fitted. You have to replace the 'bungs' in the top of the fuel tank, three of them. We assemble it all with light LM grease to make the final fit eaier. Small hands will help!!!!!

We allow four hours to do this job, excluding paint drying time. You only need to do this job once in the life of your van, but almost everyone who is new to T3 gets this rather smelly and shocking problem. This is our love affair.

Good luck...... Mojoh

Cheers for the info, this is on my winter 'to-do' list

[colincolin64]

Thanks mate you have been brill wer do you buy all your stuff from for this project do they do a kit or is it individual stuff to get thanks colin

[Mojoh]

If you are in the UK, I think Masters Brickworks have all the bits you need.
I would highly recommend also replaceing the filler neck plastic and rubber that sits right under the door. This is a rust prone corner and as you have the tank out, this is an ideal time to clean up the mess that is normally hiding behind the filler neck. Take everything out of the way, wire brush the area (bit of a dusty dirty job but) and then paint it all in good old Hamerite. Putting the neck part of the fuel tank back together is in my opionion the most complicated part of this whole job because the plastic part of the neck that fits into the body is a sort of plastic bayonet joint, i.e., you have to twist the whole thing slightly clockwise for it to lock into the body. Most people get this wrong, or only half done. It's a bit of a bitch, but as you have it all clean and painted, it should slide home more easily. After the plastic part comes the rubber condom that attaches to the filler pipe and filler neck. This is the round disk that locks the filler cap in place. It has three screws holding the whole lot together. As said, this part of the job is the most complicated, but worth the time and patience.

For sure, one of my customers will turn up with this job to do.... omg. Have fun.

[Ant-t]

I might need to do this soon, cheers for the info

[pionte]

Top work Mojoh, great write up .I recently replaced my tank and I rekon this is the worst job that I have done on A T25 , and I have done most of the horrible ones ( exhaust studs , early water pump, engine swaps, clutch , gearbox etc etc....

I still have a slight issue where my tank is a real slow filler , up to half way its fine then I have to go really slowly or it bubbles out of the filler neck.... Im assuming that I may have trapped a breather pipe ? the balance pipe from left to right appears fine, I can just about see it if I climb in where the spare wheel lives.

Have you ever had this problem ??

[pionte]

Found the problem... Still the worst job though!

[Smcknighty]

What was the problem? Putting my tank back in a couple of weeks I hope.

[Mojoh]

Oh my goodness, I did the wrong thing by writing about this issue lol.
OK, back to the drawing board. In principal, all tanks are about the same, giver and take the odd milimeter.
Presuming you've done the right things (as described earlier), your tank should be fume free, fast fill and sealed...

So, now you've still got a problem, slow fill. That means trapped air. Why?

The breather pipe across the top of the tank is the "bar-steward" (can I say this here? ). ((northern accent)).

If there is a kink in it, if the T pieces that insert into the rubber condoms on top of the tank are damaged, if the breather pipe from the RHS of the tank to the filler neck are damaged, here is your 'bottle neck' of air. These two larger breather pipes determine the filling spead and tank balancing. The smaller pipes are all about expansion. You really need to understand the layout to know the problems, and really, this is VERY VERY SIMPLE. If I can understand it, for sure, all of you reading this will do better!......

Take the tank out...... and start again, this time more slowly and using simple logic. Air moves faster than fluid, so if the air can escape, the fluid will flow. Don't smoke a joint while considering this phenomenon. Good luck

[pionte]

evening guys... Mojoh great explanation.

I had already checked the balance pipe across the top of the tank, you can just about see it if you drop the spare wheel holder and lay inside where the wheel was , I held my phone up under and took a short video , all was okay . I was still scratching my head hence my previous question about issues .

I was at Busfest and mentioned the issue to one of the guys who works for Brickwerks , he stuck his head under the filler side and said I had the plastic breather part of the filler neck tube routed wrongly, kinda twisted the wrong side , he kindly pulled it out and refitted it for me.

The next fill up was all okay, so I think that this must of been the problem , I will try again when I need to refill next.

Thank you for taking the time to reply .

[Mojoh]

Great. RHS Breather pipe..... to filler. As said..... (should have expanded on that one further, but you got it).

OK, keep to 45 litres fill up.... any more and you are probably gonna get a load of smells anyway!

Life with a T3 (T25). Full of adventure, full of drama. That's what we love.

Mj