Reply to thread

Message: [QUOTE="TARM, post: 152765, member: 578"] "Water caused the issue with the pump." While that certainly could happen to a pump in a properly setup AD I can not see it happening. You would also have likely seen the type of damage you see with pump cavitation. As has been said prior under vacuum its pulled thru the filter and perpulator perculator or whatever they call the vacuum stage I air removal part ( this is the part the FASS do not and can not have as its patented.) From those pics after seeing a good number of burned out pumps as well as the few I personally had on my 7.3 until I switched to a Bosch it looks like a typical over-heating "thermal" failure. That could have been from a jam but you not finding anything and the conditions of the parts rules that out most likely. My guesses are: a defective motor or internal wiring too higher of vacuum causing thermal overload the following one happen way more IMO than people think: improper voltage for the load making it to the pump. It seems not very many people that are just basic back yard much have or use multimeter much. Its very possible you could have an issue in that area. Smaller gauge wire , length of the wire run, and quality of wire and connectors effect how much of the full voltage reaches the pump. For every bit lost the amperage and thus thermal goes up to make up the loss of flow rate. An improper or compromised ground can cause basically the same types of issues. The alt itself not producing the voltage its suppose to. Another thing as I am not sure how the current ADs do pressure reg but if its post second stage filter where it sees pressure then a clogged or under flowing filter could create a high load from excessive pressure. Of course as I stated early on it could just be a defect in the pumps motor or its internal wiring. But its always a very good idea to confirm none of the other things listed above are not present or an issue as you will likely be having a repeat of the issue if not just with the hp pump by itself if no lift pump is reinstalled. Personally if you like the idea of a lift pump to take the vacuum load off the HP pump a Carter 460o/4601 is diesel and marine rated. The pressure is low enough to not be an issue if you put the water sep after. With that or if you ever or anyone else puts in AD FASS or any pump in a lift pump position there is a extra step that will help prevent a lift pump failure taking out your more costly main pump. Plumb and wire in a fuel pressure sensor and gauge after the lift pump but before the HP pump. As long as you see positive pressure you know the HP pump has no load from its feed or input side its only load is from building pressure post pump which is what its does best and is built for. You could set it up with a trip light if you wanted where a small red or yellow light trips in the cab if you lose pressure so you know you have a issue. IMO on things that can cause costly damage things like warning lights are hard to beat. You may not notice a dead fuel pressure reading driving but a red or yellow light tripping and lighting up will grab your attention fast. Hopefully save ruining a set of costly injectors barrels and plungers. [/QUOTE]