TM-9-2815-220-24

AVDS-1790 2CA, 2DA and 2DR Air-Cooled 12-Cylinder Diesel Engines

TECHNICAL MANUAL; UNIT, DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL FOR AVDS-1790 2CA, 2DA and 2DR Air-Cooled 12-Cylinder Diesel Engines

TM-9-2815-220-24 - Page 301 of 1563

TM 9-2815-220-24

FUEL BACKFLOW VALVE TEST

0046 00

WP 0046 00-1

THIS WORK PACKAGE COVERS:

Test

INITIAL SETUP:

Tools:

General mechanic’s tool kit (item 121, WP 0176)

Expendable and Durable Items:

Air supply

Container for fuel, minimum one gallon capacity

Personnel Required:

Track Vehicle Repairer (1) 63H10

Equipment Conditions:

Engine removed from vehicle and placed on a

flat stationary surface

The fuel backflow valve is a dual purpose valve.

•

It incorporates a check valve that prevents pressurized fuel generated by the purge pump

(wobble pump) from back flowing into the primary fuel filter.

•

It incorporates a by-pass valve that limits the fuel pressure to the manifold heaters.

The most notable symptom produced by a non-functioning backflow valve is a non-

functioning manifold heater.

To determine if your backflow valve is functioning properly,

perform the following test.

TEST

1.

Check free flow of valve (1).

a.

Disconnect hose (2) [fuel out of valve] from outlet fitting (3).

b.

Provide a suitable container to catch fuel.

c.

Provide 0.5 psi at valve inlet fitting (4).

d.

Fuel must flow freely at 0.5 psi from outlet fitting (3).

4

2

3

1