Petrol engines Fire warning
Introduction
Historically, VW buses are known to be more prone to fuel fires than many other petrol vehicles! So this is well worth reading if you are new to VW buses/transporters of any vintage - the T25 is no exception!
Always investigate a persistent smell of petrol - do not ignore it
Replacement fuel hose has internal diameter of 7mm and you'd need 2M to do from tank to carb (2WD). The cheap stuff from GSF with material exterior, just keep an eye on it as you can't see the hose breaking-down inside the external cover. Don't use cheap jubilee clips, get proper fuel hose clips (requiring proper crimping tool) to hold it on. The best stuff has a fabric material sandwiched between two layers of rubber.
There is many a bus that has burst into flame because the fuel lines have not been replaced or inspected for many years
If you have just bought your bus do them all so you know that they have been done. The best stuff has the braiding sandwiched between two layers of rubber as you look at it in cross section, the one with braiding on the outside is not recomended as you cannot inspect the condition of the rubber; that said fuel lines can degrade from the inside out so an external inspection is not always reliable. Use proper fuel line clips, not small jubilee clips as they can pinch the hose and damage it, or not close up uniformly. Replace the line from the carb to the solid line that comes into the engine bay as a priority.
Some fuel hose currently being retailed, even bearing correct markings, can quickly perish, swell and leak. When you have replaced a fuel line, re-inspect it monthly and annually - Read this 8090 thread: Problem with new Pearl Products fuel hose
Good fuel line and clips are sold at Halfords.
Use proper fuel-hose clips, NOT overtightened small Jubilee clips which lose circularity when used in this way. Proper fuel-hose clips generally use a nut and bolt to tighten them, have a small diameter/size tolerance, so get.match the correct ones.
Pay attention to every part of the fuel feed system, even the stub-pipe fitting into the carb (part of the carb, especially on Solexes - Petrol engines aircooled - Fuel Leaks
Some later vehicles have a plastic Tee-piece mounted on the engine bulkhead - these can perish and crack and have been known to be the cause of escaping petrol and fires. Injection models (2.1 DJ, MV etc) at risk due to higher pressure in fuel lines, any small leak leads to sprayed fuel, then vaporised and if ignited a fire. Yes, we are trying to worry you, so all owners check so reducing this likelihood of VW van/bus petrol fires...
Fuel flooding engine
Float valves on carburretor engines have been known to stick, so with an electric fuel pump filling the inlets and subsequently the sump via draining down. This is dangerous! If the engine hydraulic locks, or the oil level appears to have risen, then this could be one reason... either fuel or water in sump.
Case History: Woke up this morning and the van was smelling of petrol and it was slowly dripping out of bottom of the dipstick, the fuel pump must be dodgy or and the float sticking on the carb (gravity through the night?)
Filler/filling leaks
Read this topic by Simon Baxter also to glean an idea of the problem Filler/filling problems - Good link
T25 fuel tanks have a depression in them on the top that collects water and dirt. This corrodes the tank top allowing fumes and sometimes fuel to leak. If aftre filling up you smell fuel, or if the tank won't take a fll fuel volume, combined with very poor mpg, then suspect a problem with the filler neck, filler tube, tank breather system or rusted and perforated fuel tank (quite common now these are all approaching 20 yeasr old with some 25 and more.
2WD vans/buses also have two overflow tanks in the wheel arches which also can be the problem, with their pipework and the tanks themselves.
T25s have a complicated fuel tank breather system, which develop problems with age, spill-valves leaking/sticking, breather hose perishing etc.
Syncros
Syncros have a 70 litre plastic saddle tank over the gearbox and the filelr is at the rear. However, they suffer from similar problems and filling/leakage as their 2WD cousins, with some specific differences.
See here: Syncro Fuel System - Problems
