New fass losing prime.

motoking_1990

motoking_1990

Active member
May 9, 2011
1,957
5
38
Terre Haute, IN
I put a new fass on yesterday and now i am having a priming isssue. Only takes about 5-10 pumps on the ball and its hard. Doesn't take long for the prime to go away either about 5 min or less.
The previous owner put oversize lines on when he put the raptor pump on. The raptor was mounted to the frame rail, this pump sits on the left side of the fuel tank. I had to run the lines different but I dont that matters. Anyone know if the pumps are preset or should I try turning the fass up to keep prime? Any ideas could be helpful.
 
andy-stevenson

andy-stevenson

New member
Jul 7, 2013
838
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0
Anyway you bent the feed line elbow on the fuel sending unit?

When I installed my airdog I bent the rusty elbow and put a split in the side of it. So it was sucking air in, truck would idle fine, but kept dying when I tried driving it.
 
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motoking_1990

motoking_1990

Active member
May 9, 2011
1,957
5
38
Terre Haute, IN
no its rubber from the elbow to the pump. all i did to the elbow was plug the line into it. just checked to make sure its not kinked or bent.
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Awenta

Awenta

Active member
Sep 28, 2014
4,090
2
38
CT
You can modify the stock pickup but it should run on a stock pickup with no problem.

Your primer pump maybe be leaking. No leaks on any lines?

Sent from my SM-N910V using Tapatalk
 
TheBac

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
15,618
1,875
113
Mid Michigan
You have a pinhole air leak somewhere in the system. It will not be easy to find. Go back over everything, including the fuel filter. Good luck.
 
02greysixer

02greysixer

Active member
Jun 4, 2011
1,829
7
38
North Central FL
How far have you driven it since installing the Fass? Did you prefill the filters before starting the pump? If using the factory pickup I've had a hard time getting air bled from them upon initial assembly. Took a few test drives before the pump quieted down and truck started normal. Are the filters in the correct places? If memory serves the water separator goes toward the rear of the truck (assuming you mounted it how/where fass says) Are they the proper filters?

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motoking_1990

motoking_1990

Active member
May 9, 2011
1,957
5
38
Terre Haute, IN
The filters were on it already in the box. All I did was take them off one at a time and put oil on the o rings. I installed a whole kit with filter and everything. I did not pre fill the filters. I sprayed wd in the engine side like instructions said. I also mounted the pump per instructions. Only thing I didnt do was tie in above the fuel cooler like the instructions said because previous owner deleted factory fuel line.
 
motoking_1990

motoking_1990

Active member
May 9, 2011
1,957
5
38
Terre Haute, IN
I am getting diesel on top of the main plate. Not sure the exact name of the part. Its the flat center section of the pump everything attaches to it. A main body of the pump i guess you could call it. Something is leaking on top. I will have to figure it out later in the week.
 
02greysixer

02greysixer

Active member
Jun 4, 2011
1,829
7
38
North Central FL
I did have to disassemble a brand new one once that had a leak right out of the box. An O-Ring in the body was pinched. Replaced it and good as new

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