Fuel Pump Leaking at Crankcase Joint

[RupertW]

Hello all, 

I've just come back from a test run after fitting a new diaphragm to the fuel pump on my 1934 Box Saloon. The car seems to be running better, but on returning I found quite a considerable amount of oil around the fuel pump. After cleaning it up and starting the engine again it appears to be coming from the bottom of where the pump joins to the crankcase. 

When I refitted the fuel pump I used a new gasket and cleaned the faces, but didn't use any gasket goo as I assumed it wouldn't be needed with a new gasket. The two bolts holding it on are done up well, and I wouldn't like to put much more force into doing them up. 

Does any one have any experience on what might be causing this and if it's likely to be as simple as refitting with a bit of gasket goo? I noticed there's some sort of breather hole where the pump attaches to the crankcase, so I'm wondering if there might be something more amiss with how I've put things back together.

Any thoughts much appreciated!

[Reckless Rat]

Most likely that the face of the fuel pump where it bolts to the crankcase is not flat. This often happens when the bolts have been overtightened. You can repair it by firstly removing the actuating lever and then rubbing the flange on some fine emery cloth on a flat surface. Then re-assemble using gasket compound on both sides of the gasket.

[RupertW]

Most likely that the face of the fuel pump where it bolts to the crankcase is not flat. This often happens when the bolts have been overtightened. You can repair it by firstly removing the actuating lever and then rubbing the flange on some fine emery cloth on a flat surface. Then re-assemble using gasket compound on both sides of the gasket.

Thanks for your response. I've actually just taken the fuel pump off again and discovered that I somehow managed to put the gasket on the wrong way round so it wouldn't have been lined up properly. I'm assuming this was the cause as it wasn't leaking previously and the bolts came undone extremely easily so didn't seem overtightened. I'll put it back together with some gasket compound and see if that sorts it.

[Reckless Rat]

The hole at the bottom is the oil return to the crankcase - the gasket does only go on one way!

[RupertW]

I'd fitted it the right way up, just not the right way round if that makes sense, so a fairly basic error on my part. I blame late evenings working in a cramped and poorly lit garage!