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 655 of 1563

TM 9-2815-220-24

FUEL BACKFLOW VALVE REPLACEMENT

0081 00

THIS WORK PACKAGE COVERS:

Test, Removal, Installation

INITIAL SETUP:

Tools:

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

Mandatory Replacement Parts:

Lock washer (2) (item 92, WP 0175)

Expendable and Durable Items:

Container for fuel, minimum 1-gallon

capacity

Personnel Required:

Track Vehicle Repairer (1) 63H10

Equipment Conditions:

Engine removed from vehicle and placed on a

flat stationary surface

REMOVAL

•

To determine if your backflow valve is functioning properly, perform the test in WP 0046.

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

functioning manifold heater.

The fuel backflow valve is a dual purpose valve.

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

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

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

The fuel backflow valve is mounted on the damper housing on all 750 horsepower AVDS-1790

engines.

There are two mounting configurations, one on the 2CA and 2DA engines and another

on the 2DR engine.

In addition, the fuel out of the valve fitting is a straight fitting on the 2DR

engine.

Removal and installation procedures are similar.

The two configurations are illustrated

below.

2DR Configuration

2CA and 2DA Configuration

WP 0081 00-1