The Classic Machinery Network

One of the chaps working on it said it was the worst one he'd ever seen, he obviously hasn't visited any of the farms near me!

Found this, check out the health and safety!

https://m.youtube.com/watch?v=lDwMwC07Drw

Is this the type of clutch you have?
Wingett or thwaites dumper, repair drum clutch

On the lift pump (2nd pic) undo the centre bolt on the top and lift off the cover. As Slooby says there is a gauze fikter screen in there that should be cleaned every time you change the diesel filter, just be cateful when re-tightening the bolt as the threads will strip easily if you over do it and...

This one on Ebay looks similar but it has 5 stud wheels front and back

https://www.ebay.co.uk/itm/VINTAGE-BENF ... ect=mobile

Give these a try
John
https://ukconstructionparts.com/benford-dumper-parts/

Maybe a can of diesel treatment that has a lubricant in it added to a tank of fuel?

If a tap doesn't free it off the only way is to lift the top cover enough to flick it back round by hand. You can do it without removing the pump but it is the only way you will free it. If the gasket doesn't tear it only takes a few minutes

Ahh, could be the metering valve sticking. Sometimes giving the side of the pump a tap (not hard enough to break anything) will free it off. You can free a stuck metering valve by lifting the top cover up just enough to get a small screwdriver under it to flick the top of the lever back, but there i...

CAV pumps seem to be developing more problems with modern low sulphur diesel, it doesn't have the lubrication properties to keep the pumps free and gums up the internals. No fuel to the injectors can be several things from a stuck metering valve to the plungers sticking in their bores in the pump or...