TM-9-2350-311-20-1

HOWITZER, MEDIUM, SELF-PROPELLED, 155MM; M109A2, M109A3, M109A4 AND M109A5

TECHNICAL MANUAL; UNIT MAINTENANCE MANUAL FOR HULL, POWERPLANT, DRIVE CONTROLS, TRACKS, SUSPENSION, AND ASSOCIATED COMPONENTS

AUGUST 1994

TM-9-2350-311-20-1 - Page 1105 of 1275

TM 9-2350-311 -20-1

14-7 COOLANT HEATER

This task covers:

a. Removal

b. Installation

INITIAL SETUP

References

General mechanic’s tool kit (item 64, Appx H)

TM 9-2350-311-10

Lockwasher (item 95, Appx G)

Fuel inlet-to-fuel tank hose quick disconnect at primary fuel

filter disconnected (para 6-6)

Batteries disconnected (para 8-28)

a. Removal

1

2

3

4

5

6

7

Disconnect wiring harness (1) at coolant heater (2) plug.

WARNIN G

Coolant is a hazardous waste and must be disposed of in accordance with local

procedures or direction of the local Hazardous Waste Management office.

NOTE

If hoses are not plugged and outlet is not capped, coolant system must be drained

(TM 9-2350-311 -10).

Loosen clamp (3) from coolant outlet hose (4) and disconnect hose from coolant heater (2). Cap heater coolant

outlet (5) with a short piece of 5/8-in. - (16-mm-) id hose and 5/8-in. - (16-mm-) diameter plug.

Loosen inlet hose clamp (6) and disconnect coolant inlet hose (7). Install 5/8-in. - (16-mm-) diameter plug in

coolant pump (8) outlet.

Disconnect fuel pump-to-coolant heater tube (9) at coolant heater (2).

Remove screw (10), Iockwasher (11), and bracket clamp (12). Discard Iockwasher.

Remove four nuts (13), four flat washers (14), four screws (15), and two coolant heater upper brackets (16).

NOTE

Coolant heater must be lifted or tilted in order to reach exhaust tube clamps.

Loosen exhaust tube clamp (17) at heater exhaust hose (18) and disconnect hose. Remove coolant heater (2)

from hull.

14-12