As you can see from this photo, the bolts are covered in crud. Needless to say they are also made of fudge and it's not too difficult to end up with a round slot instead of a crossed slot.
If you suspect fuel is getting into the vacuum side of the pump try loosening the six bolts half a turn, and then re-tighten them. Mine were loose.
Next job is to prise the smaller of the 2 cases away from the body. I used a pair of pliers and grabbed the vac. pipe connection and GENTLY persuaded it to lift away. Don't try sticking a screwdriver inbetween the casings as it'll bugger the diaphragm.
If this cover is full of fuel then chances are the diaphragm is holed or cracked. It's this fault that allows the fuel to get into the vacuum pipe and on into the cylinder.
The photo below is of the diaphragm, the colour is probably from the bolts rusting up. A close inspection of this diaphragm for holes or cracks revealed nothing....which is nice !
Same applies to splitting this larger casing, don't stick anything sharp between them. This black diaphragm fells more like a vinyl than a plastic and it feels bloody rubbery !
This is where all the sand and bits of grit gather, as you can probably see.
Again, inspect for holes/cracks.
Next thing to do is to clean all the parts, I wire brushed the bolts, then soaked in WD40, then brushed 'em again. A bit of washing up liquid and an old toothbrush to clean the other parts. The clear diaphragm had come away slightly at the edge and so I got a cotton bud or 2 and managed to delicately clean some of the crud off the inside.
Insert a cake break here :---
Next up (munch, munch) it'll be a reassembly (scoff, chomp) and a test jobby. (yummy, yummy)
( brush of hand to remove all the crumbs ! )
