HYDRAULIC OPERATED QUICK COUPLER FOR CATERPILLAR LOAD Hydraulic fluid Caterpillar


Hydraulic fluid
`
1.1. Pump priming
2.1. Water in the oil
3.1. Suction filters
4.1. DC Motors
5.1. Wear inspection
1 The purpose of oil

The main purpose of hydraulic fluid is to transfer power from the pump to the actuators but it must also perform many other tasks which are critical to a well designed system.

First the oil must have good lubricity or be "slippery" so that the friction will be as low as possible to keep metal to metal wearing at a minimum.

Second, the viscosity or "thickness" must be in the proper range at the operating temperature so that unwanted leakage will be at a minimum, but will still allow oil to lubricate the close fitting parts in the system. (Oil that is too thin will leak past seals, valve spools and the gears; oil that is too thick will not flow properly and cause the pump to cavitate or starve.)

Third, the oil must be compatible with the seals used in the system.

Fourth, there should also be additives in the oil to slow down the effects of rust, oxidation (oxygen in the air combining with the oil to form sludge) foaming, and water settling to the bottom of the reservoir.

Fifth, the oil must be able to pour or flow at the lowest expected temperature so that the oil can reach or get into the pump.

For all of the reasons listed, automatic transmission fluid (ATF) was found in most cases, to be the best readily available fluid for the job in most climate conditions.

2. Selecting fluids for applications outside of ATF's temperature range.

When looking for fluids that can be used in the place of automatic transmission fluid or for applications where the operating temperature is outside of the range of automatic transmission fluid the following specifications should be discussed with your local oil distributor.

A. Fluid must be compatible with Buna-N sealing compounds.
B. The Pour Point must be below the lowest anticipated temperature that will be encountered.
C. It should contain Rust and Oxidation as well as other detergent type inhibitors.
D. The Viscosity (SUS) should lie between 80 as a minimum and 375 as a maximum in the operating range, with the ideal viscosity near 200 SUS.
E. The viscosity index should be as high as possible.

As an example, automatic transmission fluid (ATF) has the following specifications as listed by most oil manufacturers.

A. Viscosity (SUS)

37,8 °C 185 - 205

98,9 °C 45 - 55

B. Pour Point -42 - -37°C
C. Viscosity Index 145 - 165

NOTE: In an emergency, for cold weather applications SAE 10W non-detergent oil mixed by volume with no more than 30% #1 fuel oil or kerosene can be used.

Pump priming

New system installations, as well as those that are disassembled for repair, require proper priming to avoid possible pump failure. A pump is said to be "primed" when the internal cavity is full of oil and the air has been expelled.

Prime a pump as follows:

1. "Crack" or remove the high pressure line at or near the cylinder.
2. Operate the unit until oil flow is clear. (Air is absent).
3. Retighten or replace hose.

Water in the oil

Water can enter the reservoir through the fill hole if the unit is left outdoors or washed with a high pressure washer.

Protect the unit, whenever possible, and change oil regularly to minimize problems.

In cold weather the water will freeze and the pump will not work until the ice melts.

Suction filters

All Monarch hydraulic controls have suction filters which must be cleaned periodically or whenever flow is slow or sluggish.

Some filters can be washed in cleaning solvent and blown dry with compressed air, those which cannot be cleaned properly should be replaced.

External high pressure filters may be added to the system for added protection and ease of cleaning.

DC Motors

Motors should be serviced periodically to insure good performance.

A. Remove head assembly from motor.
B. Check sleeve bearing in head assembly for wear.
C. Place a few drops of oil on felt liner in head assembly.
D. Check brushes for wear and replace if necessary.
E. Blow dirt and dust out of motor housing.

NOTE: All Monarch DC motors turn counterclockwise when viewed from drive end. Check when replacing motor with a new one

Wear inspection

Application dictates when coupler rebuilding is required. An excessive amount of play between coupler and the attachment is an indication that wear has occurred. The coupler's top tube material is designed to wear before the attachment's hook casting.

To determine if rebuilding is required, uncouple from the attachment and place a straight edge across the coupler's top tube. If the areas where hook contact is made differ more than 3 mm from original top tube diameter, repair procedures should be implemented.

Using weld rod E7018 or equivalent, repair hook contact area by applying weld beads across the top tube until the original diameter is achieved. To help reduce acceleration of wear after rebuilding, grind high spots from the area where repairs were completed.

The same procedures for determining wear and repairing apply to the coupler's bottom tube.

The end result is for the attachment's hook assembly to make full width contact across coupler's top and bottom tube contact areas.

Review the coupler locking pins for wear. If the pin diameter differs more than 1.6 mm from original diameter, replace the pin. If ear inside diameter is 1.6 mm larger than original inside diameter, replace ear.

After rebuilding the coupler, connect to an attachment and lock into place. If locking pin does not align with attachment locking ear, remove and reposition.

Information System:

HYDRAULIC OPERATED QUICK COUPLER FOR CATERPILLAR LOAD Operating Techniques
HYDRAULIC OPERATED QUICK COUPLER FOR CATERPILLAR LOAD Using the manual
HYDRAULIC OPERATED QUICK COUPLER (WEDGE TYPE) FOR CATERPILLAR LOAD Maintenance
HYDRAULIC OPERATED QUICK COUPLER (WEDGE TYPE) FOR CATERPILLAR LOAD Operating Techniques
HYDRAULIC OPERATED QUICK COUPLER (WEDGE TYPE) FOR CATERPILLAR LOAD Using the manual
Installation Of 5G3257 And 5G4257 Rops Cab Arrangements{7325}
SUPPLEMENT FOR 936 WHEEL LOADERS CATERPILLAR BELGIUM Progressive Application Parking/Secondary Brake Control (Part of Brake Package attachment)
SUPPLEMENT FOR 950B WHEEL LOADERS (BELGIUM S.A. BUILT) Progressive Application Parking/Emergency Brake Control (Part of Brake Package attachment)
SUPPLEMENT FOR 920 ABD 930 WHEEL LOADERS Batteries (41J7796-Up and 79J7507-Up)
PSP FOR INSTALLING A NEW BRAKE PISTON TO PROVIDE IMPROVED BRAKE DISC SERVICE LIFE ON CERTAIN 966F AND 970F LOADERS - COS A LETTER NO. 5 - PS0778 - MAILED COSA
PSP FOR INSTALLING NEW BRAKE PISTON SEALS ON CERTAIN 950F, 966F AND 970F WHEEL LOADERS - COSA LETTER NO. 4 - PS0781 - MAI LED COSA - REVISED 02/95
PRIORITY - INSTALL A BRACKET TO SUPPORT THE TRANSMISSION DIPSTICK TUBE AT THE TRANSFER GEAR HOUSING ON CERTAIN 966F II AND 970F WHEEL LOADERS - COSA LETTER NO. 6 - PI3668 - MAILED COSA
HYDRAULIC BROOM FOR CATERPILLAR BACK Safety
914G WHEEL LOADER HYDRAULIC QUICK COUPLER ATTACHMENT THIS MODULE INCLUDES General Hazard Information
914G WHEEL LOADER HYDRAULIC QUICK COUPLER ATTACHMENT THIS MODULE INCLUDES Introduction
914G WHEEL LOADER HYDRAULIC QUICK COUPLER ATTACHMENT THIS MODULE INCLUDES Operation And Maintenance
914G WHEEL LOADER HYDRAULIC QUICK COUPLER ATTACHMENT THIS MODULE INCLUDES Specifications
INSTALLATION AND OPERATION LOAD SHARING MODULE Electrostatic Discharge Awareness
INSTALLATION AND OPERATION LOAD SHARING MODULE Chapter 2 - Installation
INSTALLATION AND OPERATION LOAD SHARING MODULE Chapter 3 - Setup and Calibration
INSTALLATION AND OPERATION LOAD SHARING MODULE Chapter 4 - Theory Of Operation
INSTALLATION AND OPERATION LOAD SHARING MODULE Appendix A. - LSM Control Specifications
INSTALLATION AND OPERATION LOAD SHARING MODULE Appendix B. - Guide for Handling and Protection of Electronic Controls, Printed Circuit Boards, & Modules
INSTALLATION AND OPERATION LOAD SHARING MODULE Appendix C. - EMI Control in Electronic Governing Systems