Leak where float/fuel lines come out of tank

Carbs; K-jet; Tanks; Lines; Filler necks, Senders; aftermarket fuel systems; Exhausts and Manifolds;air filters - standard and aftermarket

Moderator: Scirocco Register

Forum rules
Hints, tips and guides for repair and modification - the FAQ section on the main website is worth checking first for information relating to common faults and technical help. Useful posts and guides will be added to the FAQ http://www.sciroccoregister.co.uk/scirocco-faq
Posts: 22
Joined: Fri Aug 04, 2017 7:34 pm
fill in the right answer: 15
Location: Norfolk

Leak where float/fuel lines come out of tank

Post by timmaaah » Thu Sep 21, 2017 8:22 pm

Hey all - the missus brimmed the '92 1.8 8v carb today and when she got home the car utterly stank of fuel. There was petrol pissing out underneath, so I lifted the rear seats, took off the inspection cover and that's where the fuel was coming from. Stopping the engine and the leak slowly tapered off. Starting the car again and it started to leak from underneath the plastic sender unit/where fuel lines come out.

Upon taking the sender float unit out I saw the rubber o-ring underneath had split, causing the leak. I've syphoned a couple of gallons out.

Replacing the o-ring should replace the leak, right? It was only leaking because the level was so high and the fuel return pipe was causing a pressure build up? Should there be a vent somewhere that might be blocked? Should the tank be pressurised like that?

Explanations gratefully received thank you :-)

Posts: 3217
Joined: Thu Apr 02, 2009 9:28 pm
fill in the right answer: 10
Location: Somerset

Re: Leak where float/fuel lines come out of tank

Post by mark1gls » Thu Sep 21, 2017 9:13 pm

There is a vent valve underneath the plastic cover in the wheel arch near the filler neck which can get blocked, if you remove the plastic cover you will see some pipes running up wheel arch, follow them to the valve.

https://volkswagen.7zap.com/en/rdw/scir ... 201-66000/

New seal/o ring are available from VW part number is 113919131A, vw stock them for 5.20+VAT
Or I have seen them on eBay and VW heritage.

Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
Membership No. 323