VALVE GP-RELIEF 9T7390 - Caterpillar

Personal injury or death can result if two persons are not used in the following procedure.
Personal injury or death can result from machine movement.Place blocks in front of and behind the wheels to make sure the machine does not move while the parking brakes are disengaged.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, PERJ1017, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat® products.Dispose of all fluids according to local regulations and mandates.
Introduction
This procedure is used to purge air from the brake release system.Required Tools
Table 1
Required Tools
Tool Qty Part No Description
- 1 - Transparent tube
6.4 mm (0.25 inch) Diameter Purge Preparation
Check the hydraulic tank oil level. Make sure that you maintain the correct oil level in the hydraulic tank throughout the air removal procedure.
Engage the parking brake and stop the engine.
Install the steering frame lock.Reference: Refer to Operation and Maintenance Manual, "Steering Frame Lock" for the machine being serviced.
Put blocks in front of the wheels and behind the wheels.Purge Procedure
Start the engine. Allow the braking system oil pressure to increase to the cut-out pressure.
Disengage the parking brake. Keep the engine running and maintain the brake accumulator and the pilot system pressure within working limits throughout the air removal procedure.
Illustration 1 g06143929
(1) Air purge valve
Connect the transparent tube to air purge valve (1) on the brake release cylinder. Place the other end of the transparent tube into a suitable container for collecting the hydraulic oil. Open air purge valve (1) one-half turn.
Engage and disengage the parking brake until hydraulic oil, without air bubbles, flows through the tube into the container.
Close air purge valve (1) and remove the transparent tube.
Illustration 2 g06152615
Steering release diverter valve location
Illustration 3 g06272855
(2) Air purge valve
(3) Steering release diverter valve
Connect the transparent tube to air purge valve (2) on steering release diverter valve (3). Place the other end of the transparent tube into a suitable container for collecting the hydraulic oil. Open air purge valve (1) one-half turn.
Engage and disengage the parking brake until hydraulic oil, without air bubbles, flows through the tube into the container.
Close air purge valve (2) and remove the transparent tube.
Remove the steering frame lock.Reference: Refer to Operation and Maintenance Manual, "Steering Frame Lock" for the machine being serviced.