Fuel system leak, DIY job?
Moderators: User administrators, Moderators
Fuel system leak, DIY job?
I've got a fuel leak somewhere when the tank(s) are filled to capacity, which I think is down to a perished seal on the top of the tank.
Can anyone offer any advice about taking the tank out to fix this , other than being very careful with fuel vapour/power tools/ lighting etc?
Is it a fairly straightforward job?
Thanks everyone.
Olly
Can anyone offer any advice about taking the tank out to fix this , other than being very careful with fuel vapour/power tools/ lighting etc?
Is it a fairly straightforward job?
Thanks everyone.
Olly
-
- Registered user
- Posts: 39
- Joined: 24 Mar 2006, 14:31
- 80-90 Mem No: 0
- Location: 80-90 Mem. No. 2515 East Dorset
You should be able to reach the all the pipe connections by jacking the bus up taking the wheel off makes it easier. 5mm pipe I think. It happened to me just filled up, paid for it, walked out to see the petrol pouring out over the floor 

1986 Caravelle 2.1 Auto in Red and MG old English White Ex 7 seater morphing into a camper
- DevonAid
- Registered user
- Posts: 211
- Joined: 31 Dec 2006, 18:02
- 80-90 Mem No: 3607
- Location: SE London
fuel tank
We had a similar problem, ended up dropping the tank, and apart from top of tank seal issues, we found ALL of the fuel hoses were perished, so replaced the lot, from tank to carb and back again (return pipe). It's a bit of work although can be done on a driveway with a decent jack and axle stands, and if you source all the parts (seals, correct size hose, proper fuel hose clips, fuel filters) prior to dismantling, it makes the job a whole lot easier and quicker.
Improved peace of mind, far less fumes in the cab and expensive petrol on the fuel station forecourt, and no van-catching-fire scenario (it happens!). Lots of detailed info on this forum - use the SEARCH facility.
Improved peace of mind, far less fumes in the cab and expensive petrol on the fuel station forecourt, and no van-catching-fire scenario (it happens!). Lots of detailed info on this forum - use the SEARCH facility.
1983 T25 Devon conversion 1.9DF
Re: Fuel system leak, DIY job?
As preparation for replacing plastic water pipes I will shortly be dropping my fuel tank. Also to cure petrol fumes and leak onto forecourt when I fill it over 2/3 full. I did this about 5 years ago and assume something adrift or tubing perished. I assume that the pipe from the top of the nearside expansion tank vents to air as there is nowhere I can see for it to go? Confirm please ? When the box was fitted it compressed the pipe flat so it won't work anyway. Probably like this on most vans by now. What does the valve do and how can I test if it is working ? I only have Haynes manual diagrams.
Re: Fuel system leak, DIY job?
Have tested valve on top of expansion tank and you can suck and blow down it. Haynes call it a valve but I assume that's a one way device. Otherwise it's just a hole.
Re: Fuel system leak, DIY job?
Dropped the tank on my 1982 T25 this morning and found the cause of the fuel leak and fumes. There is a three way plastic adaptor with unequal arms which fits into hole in the top front of the tank, one each side. One had snapped in half. JK and VW Heritage don't list it . Am snookered without them or at least one. Sources or good bodges anyone




- Aidan
- Trader
- Posts: 7114
- Joined: 11 Oct 2005, 19:21
- 80-90 Mem No: 742
- Location: Llanfyllin, mid Wales : )
- Contact:
Re: Fuel system leak, DIY job?
put up a wanted ad for one and check the usual breakers, there's one all all 2wd vans . Fit pipe to van, grommets to tank and flex hoses and pipes to tank, raise tank and fiddle and fit breather top pipe and filler pipe into grommets on top of tank, a little vaseline is good on the grommets before raising it up. You can reack in over the chassis rail and push the pipes into the grommets. To remove these if ever in the future a long pry bar and some care will pop them out of the tank before dropping it, which whoever had it out before didn't know. enjoy.
-
- Registered user
- Posts: 359
- Joined: 10 Dec 2007, 21:09
- 80-90 Mem No: 4538
- Location: Surrey (Dorking)
Re: Fuel system leak, DIY job?
This is also on my to do list, as my tank chucks liquid gold over the floor if I fill it to the top.
Can all the seals still be bought for the top of the tank?
Does anyone have a list of parts needed and sizes etc, as I'd like to do it in one day so if I had the parts ready it makes life so much easier.
Cheers
Can all the seals still be bought for the top of the tank?
Does anyone have a list of parts needed and sizes etc, as I'd like to do it in one day so if I had the parts ready it makes life so much easier.
Cheers
Andrew
1600 CT Aircooled life certainly isn't in the fast lane
The car in front is my crumple zone
1600 CT Aircooled life certainly isn't in the fast lane
The car in front is my crumple zone
Re: Fuel system leak, DIY job?
I think my problem was caused by the balance pipe between the two 3 way junctions sagging then hardening and shrinking causing strain on the adaptor and eventual rupture. Probably due to water pipe being used which the petrol attacked. Problem is you cannot easily obtain proper fuel pipe of that diameter unless you nick some off a Chieftain tank or Jumbo jet.