TM 5-3805-281-24-2
Hydraulic Impact Breaker
33
BREAKER INLET PRESSURE CALIBRATION
63
1. Remove 1/4 in. gas plug (A) from high-pressure
connection (A), using 19 mm (.7480") Allen wrench.
Install flow meter in place of breaker. Connect H.P.
breaker line to INLET of flow meter, and L.P. hammer
line to outlet of flow meter. Set restrictor valve to full
open position.
2. Start carrier at low idle and check for line leaks.
Engage breaker control at low idle to bleed air from
flow meter as follows:
a. Operate hydraulic circuit by starting and stopping
circuit a few times.
b. Press electrical control switch and verify that control
valve is working by observing hydraulic flow, which
is shown as a slight movement in hydraulic popes.
c. Let oil run in system for 5-10 minutes, then switch
engine off.
d. Breaker will self-bleed out any trapped air. Run at
half-throttle for 1-2 minutes after hook-up.
3. Have an assistant in the carrier cab. Engage and hold
hammer control. SLOWLY bring carrier RPM up to high
idle and ensure there are no leaks in flow meter
connections. Close flow meter restrictor valve until flow
and pressure on flow meter are in range of the
hammer specifications. Run carrier with circuit engaged
until temperature of hydraulic oil is stabilized.
OIL FLOW CALIBRATION/REGULATION
With oil temperature stabilized and within breaker
specifications, set-up can be started. Adjust flow meter
restrictor to operating pressure of breaker. Observe and
record flow reading on Breaker Delivery Report. If
pressure reading obtained is WITHIN specified range,
proceed to High Back Pressure Level section.
Continued on next page
CED,OUOE039,5
1920MAR992/9
20-59
