TONGUE CYLINDER RELIEF VALVE (RV4) ADJUSTMENT (Sheet 1 of 1)
TOOLS: 3/1 6 in. socket head screw key
1/4 in. socket head screw key
9/1 6 in. open end wrench
SPECIAL TOOLS: Adapter ell (item 1, sec III, app B)
Adapter straight (item 2, sec III, app B)
Gage, pressure (item 3, sec III, app B)
Hose assembly (item 4, sec III, app B)
If STE/lCE is available, go to
Using 1/4inch screw key, re
Manually install gage, adapt
Engage hydraulic pump (TM 5-5420-202-10).
Set engine speed at 1800 rpm.
Slowly push down tongue cylinder control lever all the way until t
(B) is in fully retracted position.
Have second technician observe pressure gage reading.
Return tongue cylinder control lever to neutral position.
Using wrench, remove adjusting screw cap (C).
Correct pressure is 3600 ± 50 psi (24822 ± 340 kPa).
To adjust relief valve pressure, hold adjusting screw (D) with 3/16 inch screw key
and use wrench to loosen jamnut (E). Using 3/16 inch screw key, turn adjusting screw
(D) 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 (D) with 3/16 inch screw key, use wrench to tighten jamnut
Install adjusting screw cap (C) using wrench.
Remove gage, adapters, and hose assembly.
Using 1/4 inch screw key, install plug (A) and tighten.
End of Task