Claas Jaguar 2 Service Manual

Claas Jaguar 2 Short-circuit valve (747)
The short-circuit valve is integrated in the ground drive variable displacement pump (211). It is hydraulically actuated (port K). Function When stopping on an upward or downward slope, pressure differences may arise in the two high-pressure circuits, consequently ”twisting” the hydrostatic ground drive. Engaging the first gear would not be possible now. To engage a gear, the ground speed control lever must be set to position N as otherwise no electric signal can be sent from pushbutton (K) on the gearshift lever.

Keep pushbutton (K) on the gearshift lever pressed. During this, current flows through the servo gearshift solenoid valve (Y104). It switches and directs the full pressure from the low-pressure circuit (19+5 bar) to the shifter rail locking cylinder (359) and at the same time to the short-circuit valve (747). The latter switches and connects the two high-pressure circuits of the hydrostatic ground drive. The ”twisting” is therefore removed and engaging the gear becomes possible.

Diagram Tractive force (F) / Ground speed (v)
Curve a
1st forward gear is engaged, the ground speed control lever is set from its 0 position to the front.

Point 1:
Upon starting, the ground drive variable displacement pump HPV 105 swivels from 0 towards 105 cm³/rev. input volume. The ground drive variable displacement motor HMV stands at 210 cm³/rev. input volume

Here:
maximum tractive force is achieved
the max. ground speed is approx. 8 km/h.

Point 2:
The ground drive variable displacement pump HPV 105 stands at 105 cm³/rev. input volume. The ground drive variable displacement motor HMV swivels from 210 cm³/rev. to 103 cm³/rev. input volume

Here:
the tractive force decreases
the ground speed increases to up to approx. 18 km/h

Curve b
2nd forward gear is engaged, the ground speed control lever is set from its 0 position to the front.

Point 3:
Upon starting, the ground drive variable displacement pump HPV 105 swivels from 0 towards 105 cm³/rev. input volume. The ground drive variable displacement motor HMV stands at 210 cm³/rev. input volume.

Here:
the tractive force is less than in first gear
the max. ground speed is approx. 22km/h.

Point 4:
The ground drive variable displacement pump HPV 105 stands at 105 cm³/rev. input volume.
The ground drive variable displacement motor HMV swivels from 210 cm³/rev. to 103 cm³/rev. input volume.

Here:
the tractive force decreases
the ground speed increases to up to approx. 40 km/h.

Claas Jaguar 2 Control pressure line
Function
The control pressure line connects port (Y) on the ground drive variable displacement pump (211) with port (X) on the ground drive variable displacement motor (210).
Pressure is built up in the control pressure line when the ground speed control lever is pushed to the front while moving forward:

1. At a control pressure of 3...10 bar, the ground drive variable displacement pump is adjusted between 0 and 105 cm³/rev.
2. At a control pressure below 9 bar, the ground drive variable displacement motor remains in its initial position = 210 cm³/rev. input volume.
3. Starting from a control pressure of 9 bar, the adjustment of the ground drive variable displacement motor starts.
4. At a control pressure of 9. 12.5 bar, the ground drive variable displacement motor is adjusted between 210 and 103 cm³/rev. input volume.

When the input volume is reduced, the ground speed of the JAGUAR increases while the tractive force is decreased at the same time.

Bleeding the control pressure circuit

1. Stop the engine, remove ignition key.
2. Set gearshift lever to N position.
3. Another person removes the lock and unscrews the bleed valve (104) on the ground drive variable displacement motor by approx. 1 turn.
4. Start the engine and let it run at minimum rpm.
5. Block machine by actuating the service brake and the parking brake.
6. Push ground speed control lever fully to the front for 1 minute.
7. After this, the other person closes and locks the bleed valve (104).

During the bleeding procedure, the pump constantly forces oil (volume flow) through the control pressure line (port X) to the ground drive variable displacement motor (210). Here the oil and the air contained in is bled into the body of the ground drive variable displacement motor (210); no oil leaks from the bleed screw (104). If the bleed screw (104) remains open by mistake after bleeding, the maximum ground speed is not reached as the necessary control pressure (in the control pressure line) cannot be built up.