1-1. Purpose. This bulletin provides instructions and guidance on methods of exercising all types of recoil mechanisms
and equilibrators, mounted on weapons or unmounted, on weapons not fired for prolonged periods, in the field, in storage,
or at a manufacturer or overhaul facility.
a. The instructions in this publication are applicable to operator, organizational, direct support, general support, and
depot maintenance personnel responsible for exercising recoil mechanisms and equilibrators.
b. This publication provides periodic preventive maintenance that is not covered in pertinent weapon manuals, and
specific methods for exercising each type of hydropneumatic recoil mechanism, hydrospring recoil mechanism, and
c. Only the particular recoil mechanisms listed in table 1-1 do not require exercising.
Table 1-1. RECOIL MECHANISMS WHICH DO NOT REQUIRE EXERCISING
RECOIL MECHANISM MODEL NUMBER
HOWITZER, PACK: 75-MM, M116
*HOWITZER, LIGHT-TOWED: 105-mm, Ml 01 and
*HOWITZER, MEDIUM, TOWED: 155-mm, M114
HOWITZER, LIGHT, TOWED: 105-mm, M102
**HOWITZER, MEDIUM, TOWED: 155-mm, M198
*M101, M101A1, and M114 Howitzers with other recoil mechanisms will require exercising.
**U.S. Marine Corps (USMC) Howitzers are to be exercised.
1-3. General Exercising Procedures.
a. General. Exercising is the moving of rods and pistons in the recoil mechanism to reestablish a fluid film between
the packings, seals, and sliding surfaces. It prevents drying of seals and corrosion of rod surface at the packing.
Variations of exercising methods may be used, depending on availability of equipment. The exercising method selected
must not be performed in such a way as to be injurious to the weapon and thereby cause future malfunctions. Deficiencies
noted will be recorded on appropriate forms in accordance with DA PAM 738-750.
b. Exercising Frequency. Hydropneumatic and hydrospring recoil mechanism and pneumatic and hydropneumatic
equilibrators must be inspected and exercised at least every 180 days. There are two configurations of Ml1 9A1
recuperators currently in use, refer to TM 9-1015-252-10 for differences between "old" and "new". The "old" recuperator
(NSN 3040-01-340-4823) must be exercised every 30 days, while the 1tnewn one, referred to as the Low Temperature
Recuperator (LTR), (NSN 1015-01-3625288) must be exercised every 90 days to maintain them in a serviceable condition
when not in use. This
Change 2 1-1