Where to connect hoses for fuel leak test 1998 Merc 5.7 efi

[fotonews]

The following info doesn't say where to connect hoses, can someone please tell me for a Merc 1998 5.7 efi?

Step 1 - Testing for an airbound/leaky system
This is the easiest of the tests. For an airbound system all you need is the clear vinyl line and a couple of barbs. You do not need the gauge at this point. Splice the clear test line (and I say TEST LINE, because this is for testing purposes only, NO BOAT, should ever be used with vinyl line outside of TESTING PURPOSES!!)
Start the boat up and run it. Look for bubbles in the clear line. A small bubble here or there every 20 or 30 seconds isn't a big deal, but if you get a somewhat steady stream of bubbles then you have an air leak.

 

[Fun Times]

Hi there, you must be referring to JustJason's fuel testing of the boats fuel system, not the engine's fuel system.

In step 1, I believe he's referring to testing for air bubbles between the fuel tank anti siphon valve fitting and the inlet fuel pump. Placing a new clear hose between the fuel filter base outlet to the inlet fuel pump, you don't want to see air bubbles. If you suspect a bad fuel filter housing/base then a clear hose between the fuel tank and fuel inlet filter base may help confirm that theory. < Also using a vacuum gauge inline between the tank and filter, the vacuum should not be above 2" Hg max. The lower the better. Good luck.

http://forums.iboats.com/forum/engi.../290505-how-to-testing-your-boats-fuel-system

 

[fotonews]

Thank you Fun Times, i did connect a clear vinyl hose between the anti siphon valve and the fuel filter. I notice there is always air in the hose, from idle to 1500 rpm's always a pocket of air, is this normal??