Lit. No. 30118, Rev. 00
June 15, 2020
56
STRIKING AN OBJECT WHILE PLOWING FORWARD – HYDRAULIC
System Response
1. Hydraulic
fl
uid is trapped in the base end of
the driver-side ram by the CV4 check valve,
RV5 relief valve, and PC1 pilot-operated
check valve.
2. Hydraulic
fl
uid is trapped in the base end of
the passenger-side ram by the CV3 check
valve, RV6 relief valve, and PC2 pilot-operated
check valve.
PRIMAR
Y
MANIFOLD
SECONDARY MANIFOLD
LIFT RAM
RAISE
LOWER
RV2
S4
RV1
LEFT BASE
LEFT ROD
RV3
RV5
CV4
CV1
PC1
RV4
RV6
PC2
CV2
CV3
S3
SV5
S5C2
S5C1
S6
S6C1
S6C2
CV5
INTERFACE
INTERF
ACE
T
PUMP
TANK
S1
CV6
S2
SV4
RIGHT ROD
RIGHT BASE
3. When the snowplow contacts an object while
plowing, the force of the impact increases
hydraulic pressure in the base end of the ram.
When the pressure exceeds 3000 psi, the
ram's base-end relief valve opens (RV5 on the
driver's side, RV6 on the passenger's side),
allowing
fl
uid to
fl
ow back to the reservoir.
4. Due to the small volume on the rod side of
the piston,
fl
uid is not replaced. This causes a
slight temporary vacuum in that circuit.
