priming webasto fuel pump

[Manlio]

I had my webasto dosing pump stop working.
As I hear the pump clicking but no diesel fuel reaches the burner I presume the pump works but is unable to prime.
I checked fuel line and filter are OK.
Anyone knows if the metering pump must be primed ? and how can I do it ?
Thanks
Manlio

 

[vyv_cox]

These little diaphragm pumps will self-prime, just the same as your fresh water pump does. Because they are small it doesn't take much of a restriction to stop them. I suggest you take the discharge hose off the pump and ensure fuel is getting that far. If not, then there is a problem upstream. If it still doesn't work then, there is a problem downstream.

 

[Manlio]

webasto pump

Thanks for answering.
I did already a check upstream and down stream. The pump is not feeding any fuel despite clicking. The piping is clear and fuel runs freely. I checked with a syringe. That's why I was thinking to priming the pump. BTW I don't think it's a membrane one, but a piston type. A membrane will never get an high pressure as needed.
Thanks
Manlio

 

[vyv_cox]

BTW I don't think it's a membrane one, but a piston type. A membrane will never get an high pressure as needed.

Membrane pumps are used in the nuclear and petrochemicals industry at pressures up to 400 bar.

I don't have Webasto, mine's an Eberspacher, this one

Might be a piston but I had assumed, from memory, that it was a membrane.

 

[noelex]

I use a small electric fuel pump for my fuel polishing system. On installation it would not prime. I used my vacuum engine oil extraction device to initially prime and its been happily pumping ever since (its going now).

 

[Stork_III]

Mine always self-primes. Make sure the thermostat is on full, to get maximum pump speed.

 

[mersey]

Mine looks similar to the picture that was posted.

It's for a Webasto 3500, I can tell the difference in clicking when there is no fuel going to it, higher pitched clicking, and a deeper thud when it does have fuel.

I've always found it to self prime.