Took the bus out for a long drive yesterday. Before leaving I checked the oil and generally reviewed the engine bay - no leaks or issues whatsoever. Took her for a good 60 mile drive without any smells or issues but on returning home and after a few hours I went back out to tidy some wiring and noticed fuel dripping from the nearside carb. Engine is a 2ltr Type 4 with standard solex's. Any views on why it would not be leaking before I set off but is now? I'll try and get some pictures up later and will try and dry it off with kitchen roll to see if I can ascertain the source of the leak. Just seems odd to me. Noticed a smallish (6 inch) wet patch under the bus this am which is the result so suspect its still dripping. Worried it may not be safe to drive now.....
If not a fuel pipe leak, probably the float needle valve either not sealing or being held open by foreign matter. It needs sorting as the fuel can contaminate your oil, as it can syphon from the tank when engine switched off. Check your oil level, when this happened to me I got a 10 litres of oil/petrol mix out of the sump. Lucky I didn't start the engine.
OK - will check oil as it was clean and bang on between the lines when I drove yesterday. I'd assume it will have got higher if its leaking into the engine?
yup if it has siphoned over night there will be an increase in level. I also smelt the petrol which is why luckily I didn't start it up. Of course it may just be a leaking supply pipe check easy things first.
Just found this (below in blue) on the samba, admittedly the guy has a type 3 but same engine type right? It's exactly the same situation I have. The bus was originally parked on my sloping drive with the nose downwards and when I came back from yesterdays run I parked it nose up. I am going to give everything a good clean, check my oil and all my pipes again and see what's what. The benefit of parking it this way means I'll also have the sun on my back while I work instead of being in shade! Having battled with this for a very long time - I think I may have found the cause & solution. Apologies in advance if it has already been covered elsewhere. The problem seems to come from the position of the fuel tank relative to the carburetors. When the tank is full or the car is parked nose-high, the fuel level in the tank is higher than in the float chambers and sufficient pressure accumulates in the fuel lines to push the needle valves open. Fuel then siphons into the float chamber and once that is full, fuel starts dripping from the main discharge tube. Looking through various VAG publications this issue seems to have been around eversince dual carbs were first used on the type 3 engine. Two fixes have been applied by the VW engineers: On early cars, a simple check valve was positioned in the fuel line to the carbs which presumably only opens once a certain pressure is applied to it, thus preventing any flow when the engine is stationary. (I have yet to hold one of those in my hand for a closer look so please correct me if this description is incorrect.) On '66 and later cars a cut-off valve was incorporated in the top part of the mechanical fuel pump, to stop the fuel from siphoning when the engine is not running. Only the OE Pierburg fuel pumps - p/n 311 127 025 A, had this feature. I have since installed rebuilt Pierburg pumps for both my cars and there has been no driping that I'm aware of. Rebuilding & setting up a stock Pierburg pump is dead easy, only issue is the rebuild kits that are a bit difficult to come by but not impossible. I used kits made by a German company called EffBe, p/n MPE 80V1 which contained everything that was needed. There has been a few issues with hot starts and possible vapor lock since installing these pumps but I haven't been able to pinpoint them as the culprits yet. I'll write more about that later.
That may well be true but in my case it was siphoning through defective float needles which was sorted by replacement. Hope you get it sorted, Stu.
OK - update. Wiped down the manifold and general area with rags. Then tried to start her up - flooded but eventually started, left big puddle on drive. Switched her so she is now nose downwards and then cleaned up again. I placed kitchen towels under the bus weighted down with odd and sods and that was nearly two hours ago. Not a drop on the kitchen towels or in the engine bay either. No fumes either. Will leave it like this for few more hours and keep checking. It reminds me of when I was in France in 2010, I parked nose up with a pretty full tank and when I came back she wouldn't start. Had to roll backwards down the hill, pull a 180 and then she then started first time. Notes for future parking strategies...
