Is Figure 50 of TM 9-8012 (Jan56) Accurate?

RonD2 · Post by **RonD2** » Sat Jul 11, 2015 9:58 pm

I think this might be a confusing post, but here goes. Rookie questions.

The figure in the TM shows the line labeled as "vent" connected to the fuel filter assembly. My fuel filter assembly (in the tank, below the plate) has a filter surrounded by the tube reaching down into the tank about 1/4-inch from the bottom. The connection is a 3/16 double flare fitting. The P.O. had this line routed out the rear hole towards the rear axle, then just stubbed off (open to atmosphere).

He had the line going to the fuel pump connected to the 1/4-inch double flare fitting that lays close off to the side of the filter assembly.

Is this correct?

How does a fuel pump pull fuel from a fitting that doesn't have a tube submerged in fuel? And why would a vent line run through a filter to the air cleaner?

Please straighten me out. Am I missing something huge here? Either that, or it explains why the motor ran like crap --- when it ran at all?

I think I have some challenges ahead......but wouldn't trade them for anything.

Post by **wesk** » Sat Jul 11, 2015 10:15 pm

The tube coming up from the filter goes to the pump. The other fitting on the top of the filter plate is the vent and goes to the air cleaner. Fig 50 (Edit to read 51) shows it as it is suppose to be. What you describes makes the PO appear to not have both paddles in the water!

RonD2 · Post by **RonD2** » Sat Jul 11, 2015 10:33 pm

Hi Wes. Thanks! I was hoping I wasn't crazy.

But what you describe isn't what my TM Figure 50 shows. Mine shows the line coming up from the filter as the vent line going off to the side of the tank and then forward to the air cleaner.

Are there bad copies of TM's out here? Did I miss a change page? I got my set from Portrayal.

I guess I need to burn a copy of my Figure 50 and paste it here to show you what I'm seeing.

And my next question is: do I have a bad plate assembly? MDJ strikes again? Because mine has a 3/16 double flare fitting for the fuel line and a 1/4 double flare fitting for the vent line.....my understanding from the rest of the TM is the reverse --- that fuel lines are 1/4 and vent lines are 3/16.

Regards,
Ron

Post by **wesk** » Sat Jul 11, 2015 11:30 pm

I've only seen the one Fig 50 & 51 and you are correct in that they sow the two lines crossed. The filter is shown being removed and the fuel feed tube is disconnected and the bottom side of the cover is not shown. The view angle is very misleading until you get a removed assembly in your hands. If you carefully view the angle of view you will eventually see that the filter feed tube connects to the fitting closest to the top of the page. The small elbow on the cover is for the fuel feed tube from the filter and the larger domed bump is the vent line. So it appears the illustrator was not familiar with the plumbing.

RonD2 · Post by **RonD2** » Sun Jul 12, 2015 10:47 am

Wes, I beg your pardon and apologize to all (including the P.O.!) . I just took the assembly out of the tank again and put it in one hand and the TM in the other, and they're both correct.

What confused me is the label and pointer line on Figure 50 called "Fuel Filter Assy" going to the larger domed bump (vent) when it really means that's the entire assembly.

I'm learning. Just need to remember to check, then double check, and then triple check myself before posting goofy questions.

Sorry for my confusion! I appreciate your patience!

skyjeep50 · Post by **skyjeep50** » Sun Jul 12, 2015 11:08 am

The reason the gas tank has a line going to the air cleaner is so that the jeep can be driven submerged in water. The gas tank cap in this case is sealed and as the jeep is driven air is drawn into the gas tank though the air cleaner preventing a vacuum in the tank stopping fuel flow. The clutch bell housing, transaxle and distributor also have vent lines connected to the air cleaner or air cleaner cross over tube. If the jeep was to go "swimming" a snorkel was connected to the air cleaner and up the windshield, a vertical extension attached to the exhaust pipe, a pipe plug inserted into the bottom of the clutch bellhousing and the fording control was pulled closing off valves connected to the air cleaner cross over tube and PCV valve. The engine block was isolated and everything else that needed to breath was connected to the snorkel - except the driver.