Tank Pressure Sensor 3 way joint
Posted: Mon Aug 12, 2019 11:49 pm
So I think I have everything I need to get my gas tank installed....except I'm struggling with 17357-S02-L01, #5 in the diagram below. I'll call this the fuel tank pressure sensor 3 way joint.
I know one side connects to the fuel tank pressure sensor (#1 diagram below). Another side connects to a fitting (#4 on diagram) which is mounted on the frame rail. I can't seem to find anything to give any indication where the third leg of the joint connects.
Since the purpose of the fuel pressure sensor is to measure pressure inside the tank it seems this hose is the source for atmospheric pressure to determine relative pressure from absolute tank pressure. Given this I understand the purpose for a line going to the frame, but I can't understand why that would T (or Y in this case). It's orientation almost looks as if it could be a drain for condensation or in case the frame is submerged? But why route to the frame at all if leaving an end open (uncovered\filtered) and the purpose is only as as source for atmospheric pressure, why not just leave the sensor nipple open if this were the case?
Is the third leg simply left open or does it need to be routed somewhere in addition to the tank pressure sensor?
Relevant Helms pages (11-141 '98 update, 11-101 '01 supplement, ironically the best illustration I've found is the parts diagram below)
Unfortunately all is located under the shield (#9 on diagram) on the front left side of the tank so installed visibility will be limited but I'd be grateful if someone ('98+) could take a look and trace or confirm if the third leg is open.
I know one side connects to the fuel tank pressure sensor (#1 diagram below). Another side connects to a fitting (#4 on diagram) which is mounted on the frame rail. I can't seem to find anything to give any indication where the third leg of the joint connects.
Since the purpose of the fuel pressure sensor is to measure pressure inside the tank it seems this hose is the source for atmospheric pressure to determine relative pressure from absolute tank pressure. Given this I understand the purpose for a line going to the frame, but I can't understand why that would T (or Y in this case). It's orientation almost looks as if it could be a drain for condensation or in case the frame is submerged? But why route to the frame at all if leaving an end open (uncovered\filtered) and the purpose is only as as source for atmospheric pressure, why not just leave the sensor nipple open if this were the case?
Is the third leg simply left open or does it need to be routed somewhere in addition to the tank pressure sensor?
Relevant Helms pages (11-141 '98 update, 11-101 '01 supplement, ironically the best illustration I've found is the parts diagram below)
Unfortunately all is located under the shield (#9 on diagram) on the front left side of the tank so installed visibility will be limited but I'd be grateful if someone ('98+) could take a look and trace or confirm if the third leg is open.