631K and 637K Wheel Tractor-Scraper Systems Service Brake System Pressure

Service Brake System Pressure - Test

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

631K and 637K Wheel Tractor-Scraper Systems Parking Brake - Test and Adjust

631K and 637K Wheel Tractor-Scraper Systems Hydraulic Cylinder Cycle Time - Check

BRAKING SYSTEM

621K, 623K, and 627K Wheel Tractor-Scrapers Systems System Pressure - Release

621K, 623K, and 627K Wheel Tractor-Scrapers Systems Operational Checks

631K and 637K Wheel Tractor-Scraper Systems General Information (Brake System)

631K and 637K Wheel Tractor-Scraper Systems Pressure Tap Locations

631K and 637K Wheel Tractor-Scraper Systems Location of Components (Brake System)

631K and 637K Wheel Tractor-Scraper Systems Electronic Control (Brake System)

631K and 637K Wheel Tractor-Scraper Systems Service Brake System Pressure - Test

1.1. Specification

2.1. Introduction

3.1. Required Tools

4.1. Machine Preparation

5.1. Test Procedure for the Front Wheels

6.1. Test Procedure for the Rear Wheels

7.1. If the Service Brake System Pressure Test is not to Standard

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Personal injury or death can result if two persons are not used in the following procedure.

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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.

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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.

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NOTICE

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, NENG2500, "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.

Specification

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Table 1
Service Brake System Pressure - Test (Front wheels)
Date	Equipment ID Code
Description	Specification	Actual
Front Brakes	5690 ± 431 kPa (825 ± 62 psi)

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Table 2
Service Brake System Pressure - Test (Rear Wheels)
Date	Equipment ID Code
Description	Specification	Actual
Rear Brakes	11655 ± 520 kPa (1690 ± 75 psi)

Introduction

This procedure will check the service brake pressure at the front and rear wheels.

Required Tools

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Illustration 1	g01623868
Tooling (B)

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Table 3
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

Machine Preparation

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. 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.
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Illustration 2 g03720486

View of the portion of the crankcase guard requires removal to access test ports.
Remove the belly 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.
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Illustration 3 g03720495

Distant up view of the pressure tap for the front service brakes.

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Illustration 4 g03720503

Close up view of the pressure tap for the front service brakes.
Connect tooling (B) to (1) tocheck the front service brakes.

Test Procedure for the Front Wheels

Start the engine. Warm the engine up to normal operating temperature which is 60° C (140° F). Run the engine at low idle.
Depress the service brake pedal and hold the brake pedal in the fully applied position. The brake lamps should be on.
The brake pressure for the front axle should check 5690 ± 431 kPa (825 ± 62 psi).
Remove all test equipment. and reinstall the dust covers.
Reinstall the crankcase guards. 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.

Test Procedure for the Rear Wheels

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Illustration 5	g03720614
Typical example. 637K with the ejector in theFORWARD position. The picture is taken from between the bowl and the rear tire.

Start the engine and move the ejector to the forward position.
Shut off the engine.
Connect tooling (B) to (2) to check the rear service brakes.
Start the engine and allow the engine to warm up to normal operating temperature. Run the engine at low idle.
Depress the service brake pedal and hold the brake pedal in the fully applied position. The brake lamps should be on.
The brake pressure for the rear axle should check 11655 ± 520 kPa (1690 ± 75 psi).
Remove all test equipment and install dust covers.
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.

If the Service Brake System Pressure Test is not to Standard

Check accumulator pre-charges by referring to Test and Adjust, "Brake Accumulator (Service) - Test and Charge" in this manual.
Purge brakes thoroughly. Refer to Test and Adjust, "Parking Brake Purge Procedure" in this manual.
Check the accumulator pressures. Refer to the Test and Adjust, "Test and Adjust- Brake Accumulator Charging Valve-Test".
Inspect brake pedal located in the cab.