Delivery valves

[Tomoturbo55]

Should fuel leak out of the pump when delivery lines are removed?

Anybody ever encounter bad delivery valves? Should they work one way or Like both ways of fuel flow to pump and injectors?

[ORCoaster]

I believe they only allow fuel out to the injectors.  And yes they can get plugged up and can be cleaned up.

[fatmobile]

I think it depends what pump you have.
 Later pumps will flow out the delivery valves when the lines are removed.

 If you remove the delivery valves you can inspect them.
The circular area should have machine marks that go around it.
 If you can't see the lines going around and there are lines going parallel to the valve it is worn.

[sgnimj96]

Should replace those copper washers (6x10?)  when you put them back in.   Those dv's see full injection pressure.   
I read somewhere to tighten and loosen in 3 increasing steps to the final torque