631K and 637K Wheel Tractor-Scraper Systems Brake Accumulator Charging Valve

Brake Accumulator Charging Valve - Test

631K and 637K Wheel Tractor-Scraper Systems [UENR4608]

BRAKING SYSTEM

ACCUMULATOR GP

631K and 637K Wheel Tractor-Scraper Systems Brake Accumulator Charging Valve - Test

1.1. Specification

2.1. Introduction

3.1. Required Tooling

4.1. Preparation for Test

5.1. Perform the Test

Show/hide table

Personal injury can result if the machine moves while testing.

If the machine begins to move during test, reduce the engine speed immediately and engage the parking brake.

Show/hide table

Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine.

To prevent possible injury, perform the procedure that follows before testing and adjusting the brake system.

Specification

Show/hide table

Table 1
Brake Accumulator Charging Valve - Test
Date	Equipment ID Code
Description	Specification	Actual
Cut-in Pressure	15000 ± 350 kPa (2175 ± 50 psi)
Cut-out Pressure	18000 ± 350 kPa (2610 ± 50 psi)

This test will check the performance of the accumulator charging valve and accumulators.

Show/hide table

Show/hide table

Table 2
Tool	Item	Part Number	Description	Qty
B		198-4240	Digital Pressure Indicator Gp
	B1	198-4234	Digital Indicator	1
	B2	251-9600	Pressure Sensor Gp (0 to 68,900 kPa (0 to 10,000 psi))	2
	B3	198-4236	Adapter Cable As	2

Warm the hydraulic oil up to 65° ± 5°C (149° ± 9°F).
Move the machine to a smooth, horizontal location. Move the machine away from other operating machines and away from personnel. Warm up the engine to the normal operating temperature. Place the transmission direction control switch in the NEUTRAL position. Engage the parking brake. Lower the bowl to the ground and lower the apron onto the bowl. Stop the engine and put chocks in front of the wheels and behind the wheels.
Show/hide table

Illustration 2 g03715825

Looking up at the tractor with the belly pan removed
Remove the crank case guards to allow access to the control manifold for the hydraulic fan and brake. For information regarding the removal of the crankcase guards refer to the Disassembly and Assembly, "Crankcase Guard - Remove and Install - Tractor" for your machine.
Pump the brakes to remove the pressure from the system.
Show/hide table

Illustration 3 g06218162

View of the control manifold for the hydraulic fan and brake as seen from the front of the tractor.

Show/hide table

Illustration 4 g06218164

(1) Test port as seen in a close up view of the control manifold for the fan and brake. Viewed from beneath the tractor.
Connect (B) to test port (1).

Start the engine. Run the engine at low idle and place the parking brake switch in the OFF position.
Pump the brake pedal until the cut-in pressure of 15000 ± 350 kPa (2175 ± 50 psi) is reached. Allow the accumulators to reach the cut-out pressure of 18000 ± 350 kPa (2610 ± 50 psi).
Immediately shut off the engine and immediately cycle the key back to the ON position. Parking brake indicator (3) will illuminate
Show/hide table

Illustration 5 g03491397

Show/hide table

Illustration 6 g03491437

Your machine will have one of the above monitoring system displays.
Pump the service brakes at a rate of one second on and one second off. Count the number of brake applications that are required to illuminate the low-pressure warning indicator (2).
Turn the engine key to the start position and operate the engine at low idle and allow the brake accumulators to reach the cut-out pressure. Run the engine at low idle, the machine in park, and the service brakes released.
Note: The accumulator pressure should not decrease from the cut-out pressure to the cut-in pressure in less than 30 seconds.
Remove the test equipment (B) and reinstall the dust cover.
Reinstall the crank case guards. For information regarding the installation of the crankcase guards refer to the Disassembly and Assembly, "Crankcase Guard - Remove and Install - Tractor" for your machine.