Diesel Pumps - Why do they die?

Just Wondering....
Why do diesel pumps suddenly die?
What actually fails?.... is it repairable?
Is there any way of preventing it happening?

all i know is that fuel filter should be changed every 12 months especially if using veg oil and never run out of diesel cos that will kil it. They are repairable but not a home jobbie. you can get exchanges for about £500 - £700 whereas a new one will cost about £1700 fitted from vx :shock:

On a Distributor type pump (rotary) the vanes inside wear out.....this can be down to wrong fuel, water in fuel, additives in fuel.....as they wear they add small metal filings to the fuel system.....this is why its good to change the filters regularly.....the water trap (if you have one) should be drained at least weekly, the filings can build up in the tank, can damage injectors and stick to the fuel lines.
So when the pump fails you should really clean out the whole fuel system, drop and clean tank/fuel lines etc to prevent sudden recurrance with new pump.
The new generation of pumps operate at extremely high pressures (1500 BAR!) and cannot take petrol or contamination or veg oil which doesn't lubricate it sufficiently, when they go down you can kiss goodbye to £3000 plus. It must be said that many "pump" failures are actually an electrcal component attached to it and not properly diagnosed.

Hmmm,
Do you think using something like "Millers diesel plus" helps.
I've been using it for ages and it certainly seems to help with smoother running at least.

Millers Diesel plus sport 4 is designed for newer fuel systems.

http://www.millersoils.net/1_Millers_fr ... L-dps4.htm

It says "Suitable for all diesel engines" - that's why I've been using it.
I swear it makes a difference, seems to run smoother.
Also I would think the more "lube" the pump gets, the better?

Ive been using the earlier version on and off because I believe there is less sulphe in modern fuels and in earlier pumps this lubed the pump