OVERHEAD CYLINDER RELIEF VALVE (RV9) ADJUSTMENT (Sheet 1 of 1)
TOOLS: l/4 in. socket head screw key
3/1 6 in. socket head screw key
9/1 6 in. open end wrench
SPECIAL TOOL: Gage, pressure (item 3, sec III, app B)
Remove overhead cylinder armor (page 3-223)
If STE/lCE is available, go to STE/ICE Test 51
Using 1/4 inch screw key, remove plug (A).
Manually install pressure gage in opening left by removal of plug (A).
Engage hydraulic pump (TM 5-5420-202-10).
Set engine speed at 1800 rpm.
Slowly push up overhead cylinder control lever all the way and hold in that position.
Have second technician observe pressure gage reading.
Return overhead cylinder control lever to neutral position.
Remove adjusting screw cap (B) using wrench.
Correct pressure is 3600 ± 50 psi (24622 ± 340 kPa).
To adjust relief valve pressure, hold adjusting screw (C) with 3/16 inch screw key and
use wrench to loosen jamnut (D). Using 3/16 inch screw key, turn adjusting screw (C)
clockwise to increase pressure or counterclockwise to decrease pressure.
Repeat steps 3 through 9 until pressure gage shows reading of 3600 ± 50 psi (24822 ±
Holding adjusting screw (C) with 3/16 inch screw key, use wrench to tighten jamnut
Install adjusting screw cap (B) using wrench.
Remove pressure gage.
Using 1/4 inch screw key, install plug (A) and tighten.
End of Task