2002/06/24 Caterpillar

Maintaining Quick Disconnect Fittings for Increased Serviceability {5057, 7000}

Usage:

Backhoe Loader: 420D (S/N: BMC1-UP; BLN1-UP) 428D (S/N: BNB1-UP; BLL1-UP) 430D (S/N: BML1-UP) 432D (S/N: BLD1-UP) 438D (S/N: BPE1-UP; BPN1-UP) 442D (S/N: BRG1-UP; BRY1-UP)
Integrated Toolcarrier: IT14G (S/N: 1WN1819-UP) IT28G (S/N: 8CR1-UP; 9AR1009-UP)
Mini Hydraulic Excavator: 301.5 (S/N: 3YW1-UP) 301.6 (S/N: BDH1-UP) 301.8 (S/N: BFA1-UP) 302.5 (S/N: 4AZ1-UP) 303.5 (S/N: DCH1-UP; AFW1-UP) 304.5 (S/N: WAK1-UP; ANR1-UP)
Multi Terrain Loader: 267 (S/N: CMP1-UP) 277 (S/N: CNC1-UP)
Skid Steer Loader: 216 (S/N: 4NZ1-UP) 226 (S/N: 5FZ1-UP) 228 (S/N: 6BZ1-UP) 236 (S/N: 4YZ1-UP) 246 (S/N: 5SZ1-UP) 248 (S/N: 6LZ1-UP) 252 (S/N: FDG1-UP) 262 (S/N: CED1-UP)
Wheel Loader: 902 (S/N: 7ES1-UP) 906 (S/N: 6ZS1-UP) 908 (S/N: 8BS1-UP) 924G (S/N: AAN1-UP; 9SW1-UP; 3PZ1-UP) 924GZ (S/N: 6YW1-UP) 928G (S/N: 6XR1-UP)

Holmbury quick disconnect fittings are utilized in order to connect work tools and attachments to the host machines. Quick disconnect fittings provide the following benefits: speed of changing work tools and attachments, prevention of air and contaminants from entering the hydraulic system, no spillage of hydraulic oil and no need for specialized tools.

In order to maintain the integrity of quick disconnect fittings, minimal care of the fittings and routine maintenance of the fittings are essential. The following suggestions are provided by the manufacturer in order to maintain the integrity and the serviceability of quick disconnect fittings.

Note: This information is applicable to the quick disconnect fittings for the listed machines and for the work tools that are used with those machines.

Care and Maintenance of Quick Disconnect Fittings

Connect and disconnect a new fitting several times in order to exercise the seals. This prevents the fitting from sticking after periods of nonuse.
Avoid damage to the mating faces of the fitting. Burrs and scratches can damage the seals, which can create leaks. Also, the ease of connection can be limited if damage occurs. The use of protective caps will help prevent damage to the mating faces of the fitting.
Always wipe the mating faces of the fitting in order to clean the surfaces before you connect the fitting.
Always align the locking ball with the mating notch in the locking sleeve before you disconnect the fitting. Then, pull back the sleeve fully in order to disconnect the fitting.
If a fitting sticks, ensure alignment of the locking ball and the notch in the locking sleeve before you attempt to force apart the fitting. Pull back the outer sleeve and gently tap the fitting until the halves part. Use a rubber mallet in order to prevent damage to the fitting.
Never hit the center poppet of the fitting in order to release residual pressure. This is dangerous and this will destroy the fitting.
When you install fittings, never clamp onto the outer sleeve of the female half or the nose of the male half. Damage to the fitting will occur.
Never connect the halves of different fittings. Connecting a Holmbury fitting with another manufacturer's fitting will damage seals. This will also invalidate the warranty.
Never fit Holbury fittings to a system that does not have adequate filtration.
Never reconnect a fitting that is known to be damaged. This will destroy the seals in both halves.
Never leave the fitting on the ground or in a location that exposes the fitting to damage.
Never turn the coupling sleeve when the fitting is disconnected. This will result in forcing the locking ball under the sleeve.
Never disassemble a fitting. If a fitting becomes damaged, replace the damaged fitting with a new fitting.

When the halves will not couple, look for burrs on the male nose. Replace the male half. Flush out both halves.

When the female half of the fitting is leaking from the center stem, you should clean the fitting. Push back the stem and check the seals.

When there are leaks from the back of the fitting, tighten the fitting. Use the correct sized wrench.

Cleaning the Fitting

Periodic cleaning of the female half of the fitting can minimize the occurrences of sticking. Cleaning will remove dirt and contaminants that tend to accumulate inside the fitting. The recommended procedure for cleaning the fitting is provided below.

Remove the fitting. Use the proper wrench in order to prevent damage to the fitting.

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Illustration 1	g00893366

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Illustration 2	g00893368

Use a screwdriver and push back the outer sleeve. See Illustration 1.
Note: When the outer sleeve is pushed back, the inner sleeve becomes partially exposed and the operating sleeve moves forward. The internal parts of the fitting are now accessible for cleaning. See Illustration 2.

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Illustration 3	g00893370

Wash the fitting by placing the fitting in a shallow container that contains a recommended cleaning fluid. Agitate the fitting in the cleaning solution. Continue to push back the outer sleeve so that the cleaning fluid can wash the internal parts. Repeat washing until the fitting is clean. See Illustration 3.
Note: Use the appropriate protective equipment when you work with cleaning solutions.

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Illustration 4	g00893372

Remove the fitting from the cleaning solution. Close the fitting by aligning the locking hose barb coupler and pushing back the operating sleeve. See Illustration 4.