What does the Schroader fitting do on the fuel rail?

[Rovernaut]

Studying RAVE, it shows a tool to check fuel pressure as a t piece unit with a guage.
from what I gathher you check the fuel pressure by connecting it at the engine side of the fuel filter line ,
This will give the delivery pressure.
But what is the schroeder connector on the fuel rail for?
I unscrewed the cap and pressed on the valve and got a dribble.
Isn't the fuel rail supposed to be pressurized with fuel? :?:

[PhilipA]

Always there to check the fuel pressure easily. And the valve IS on the engine side of the fuel filter,if you have a 14CUX, it is before the regulator. A "Thor" has the regulator in the tank and a single line so after the reg but the result is same same.

Regards Philip A

[harry]

8) well if the engine has been running recently, you should get a fair stream of fuel from the valve.
i had a suspected fuel pressure problem and tapped a t piece in at the valve to prove the system.
the other thing is that if you suspect no fuel you can bleed off the fuel pressure to check the pump running

[Rovernaut]

Thanx guys.

[stevo]

you will find that the fitting has a very small hole which will only allow a dribble you do not need a high flow through this fitting to measure pressure these fittings are common on heavy machinary