Cost Effective Gasket and Paint Cleaning Processes

1.0 Introduction
Efficient parts cleaning processes are critical to several facets of CRC operations. Parts cleaning may be considered a non-value adding step, but it represents a substantial portion of labor and expenses in the rebuilding process. The cleaning step is an important segment in the critical path, since the last parts disassembled are the first parts needed in assembly. All other parts must wait in staging until those critical few are cleaned, rebuilt, and cleaned again before the component is ready for assembly.
There are many technologies used in the cleaning process, such as high-pressure cabinet washers, buffing, grinding, blast cleaning, and solvent washing. Ideally, the fastest and least costly process is applied to each part as needed. Automatic cleaning is typically preferred for cost control and consistent quality. Gasket removal and seal surface cleaning is difficult because it often requires extensive manual labor. Paint removal is difficult because:

• Ferrous metals require a caustic solution to remove most paints. This is expensive to buy, and the remaining wastes are expensive to dispose of.
• Non-ferrous metals require very high cost chemicals to strip paint, and these are also very expensive to dispose of in many regions.

This Best Practice will discuss paint and gasket removal without requiring such expensive chemical processes. The processes employed will provide a sufficient level of cleanliness without “over-cleaning.” These new processes will also minimize part damage and processing time/labor.


2.0 Best Practice Description
Parts cleaning is often performed by lesser-skilled employees – those with the least experience in the dealer and/or product. They are typically trained by outgoing personnel from that area, and receive little follow-up unless the rebuild technicians complain about dirty parts. Some rebuild centers will also require technicians to clean parts, with each tech being responsible for his or her own parts. Cleaners typically:

Paint & Gasket Removal Process
(Best Practice scope in green box)

• Grind and scrape all the gaskets off before the cabinet washing. This removal requires time, labor, and effort making the parts more vulnerable to damage and reducing the effectiveness of gaskets and seals. Excess grinding and scraping also creates airborne debris that will spread into the shop and require additional cleanup
• Grind/scrape all the gaskets off after the cabinet washing, typically long after the parts have cooled and gaskets have hardened, again using lots of time. This excess grinding and scraping creates the same problems mentioned above. In addition, abrasives and debris can contaminate the parts and become incorporated into the rebuilt component, and affect service life.
• Use several methods to remove paint: blast cleaning requires time and facility resources. Grinding/buffing to remove all the paint also requires significant time and labor and spreads airborne debris. Chemical removal consumes caustic, or more expensive chemicals, which add excessive disposal costs to direct expenses. Some operations don’t clean paint beyond the aluminum-safe solution washes. This omission leaves curled paint surfaces on the parts, which:

1. Creates an inferior painting surface, resulting in a low-quality product image to the customer.
2. Causes paint chips to re-enter the assembly process; contaminating bearing surfaces and blocking lubrication passages. Results can reduce service life or possibly cause early failure.
3. Creates a mess in the work bays, with paint chips breaking off the parts and flying around the shop. This adds to shop cleaning efforts and demonstrates an unprofessional image to employees and the customer.

Effective gasket and paint cleaning processes provide balance towards getting parts cleaned to a consistent quality and minimizing the time, labor, and supplies to perform the cleaning. This process follows:

• Gaskets/sealants that soften during the cabinet washer cycle should be quickly scraped off with a putty knife immediately after the wash cycle. The parts should still be hot and the gaskets should be easy to scrape off quickly. Many of the gaskets may have already fallen off the parts during the wash cycle
• Gaskets that were not softened and subsequently difficult to remove after the wash cycle, should be scraped or ground off before the second wash cycle. This will minimize post-wash grinding and further wash cycles. This is commonly required with gaskets exposed to high heat or those applied with aggressive sealing chemicals. This is common with exhaust gasket and head gasket areas those exposed to high
• Once processed by the cabinet washer, painted parts may be:

1. “Buffed” with a powered bench-mounted, or hand-held angle grinder. Although rust/corrosion should be completely removed, only the paint chips need be removed up to the point of where the paint remains adheres to the part. The sharp broken paint edge on the part should only be “feathered” to blend it into the part surface. The blend-line should disappear under a good coat of paint.
2. Blast cleaned with a automatic tumbling cleaner

• Blast clean aggressive corrosion only as needed. This may be performed manually, especially for larger/sensitive parts, or with an automatic tumbling blaster, for other parts. Blast only critical areas and blast to “feather” out paint to minimize time, labor, and supply expense. Always wash parts after blast cleaning due to the amount of abrasive carry-over.

Establish consistent and cost-effective cleaning processes:

• Perform cleaning only with specialized cleaning employees. Do not permit rebuild technician to share in the general cleaning area duties as a rule. Rebuild technicians may only clean in the general cleaning area only under special circumstances and to expedite a repair.
• Establish a training process or course to prepare the cleaning specialist. Include best-in-class visual aids and physical samples. Implement the training consistently with demonstrated qualification standards. Emphasize quality and cost effectiveness. Review performance periodically to assure quality does not drift and process improvements are documented/replicated.
• Establish cleaning equipment maintenance programs for consistent operations. Include schedules, checklists, and reliable supply delivery/inventory systems. Define individual responsibilities for equipment operators and maintainers. Enforce daily/consistently.
• Lead cleaners and disassembly technicians as a team to capitalize on the location, and opportunities to share employees between functional areas. This also allows for better parts reuse and applied failure analysis process control. Parts often must be cleaned for better reuse and AFA decisions, and a team can coordinate these processes with the least effort/ bureaucracy.

3.0 Implementation Steps

• Document as-is cleaning processes, equipment, and performance.

1. Develop practical performance metrics.
2. Document subjective observations through definitions and visual aids.
3. Account for employee experience and strategy in applying employees to function.
4. Include area equipment maintenance programs, roles/responsibilities, and adherence.

• Define future cleaning strategy based on expected product type, volume, size, etc.

1. Plan for typical rebuild volumes as well as expected peak production business cycles.
2. Investigate specialized cleaning facilities, equipment, tools and processes.
3. Utilize Cat Facility Development and Service Tools Development.
4. Visit best-in-class dealers to observe their operations.

• Apply future strategy to shop layout plans.

1. Consider staging location’s effects on product protection and flow.
2. Add changes to shop layout drawing.
3. Include shop technician teams in the review/application stages.
4. Include outside groups providing facility/equipment support functions, as needed.
5. Use Cat Facility Development and Service Tools Development expertise as required.

• Develop/document the new cleaning (and disassembly – as needed) strategy/procedure, with new roles and responsibilities.

• Establish facility/equipment maintenance strategies as needed.
• Establish adjusted repair/rebuild time requirement targets as needed.
• Establish adjusted cleaning (and disassembly) group leadership as needed.
• Present strategy to shop employees.
• Implement the staging processes, layout, and equipment changes into the shop.

1. This may occur in phases (as needed).
2. Test new processes to establish “best-fit” application for shop.

• Train employees to use the new procedures. Follow-up/enforce immediately.
• Review process and support system performance once established.
• Establish and implement adjustments as needed.

4.0 Benefits

• Increased capacity - These concepts increased cleaning stage throughput for a given amount of labor hours, by specializing and effectively training the employees. Supply control/availability minimizes production delays.
• Reduced cost – Labor hour targets per cleaning segment were reduced as mentioned above. “Over-cleaning” was almost eliminated and consistently controlled with periodic process review. Equipment is better maintained with consistent cleaners and comprehensive maintenance support. Supply control minimizes production interruptions.
• Increased quality – Reduced over-cleaning allowed time for focusing on the tough cleaning areas, and consistent cleaning methods increased the skills applied to those areas.
• Improved image – Effective processes and employees in the cleaning area promote a higher level of professionalism with the employees. A cleaner environment also promotes employee professionalism and this was immediately obvious to all customers visiting the CRC. They turned a typically “dirty corner” into a productive working area.

5.0 Resources Required

• Investment costs vary, depending on cleaning area/system related gaps found and local labor/material costs:

1. Equipment upgrades to provide product quality/consistency.
2. Facility upgrades to provide effective product flow to match new processes.
3. System development to assure facility/equipment reliability.

• Support Equipment – as needed:

1. Equipment organization aids (racks, cabinets).
2. Airborne debris containment (downdraft tables, evacuation systems, etc.).
3. Utility reels for effective facility cleaning efforts.
4. Automatic cleaning equipment (tumbling blasters, cabinet washers, etc.).

• People

1. Establish current cleaning, quality, costs, and environmental concerns with team.
2. Establish process, facility, and equipment improvements through team.
3. Establish team organization/leadership to coordinate/support contingent functions.

• Training

1. Establish the improvement benefits with the production team.
2. Define and enforce the new process and duties with the production team.
3. Define and enforce new support systems/process/duties with support teams.

6.0 Supporting Attachments / References
None.

7.0 Related Best Practices
0107-4.5-1060 -CRC Parts Buffer Enhancement
0207-4.5-1063 -CRC Material Transport Strategy
0107-4.4-1061 -CRC Parts Blasting Enhancement
0207-4.4-1066 -CRC Proper Lighting Provides Effective Working Environment

8.0 Acknowledgements
This Best Practice was written by:
Russ Young
6 Sigma Black Belt
young_russell_k@cat.com
(309) 675-4583

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Managing Fluid Cleanliness through Effective Measurement & Recordkeeping

1.0 Introduction
Maximizing component life and minimizing component cost-per-hour requires that fluid cleanliness be maintained at very high levels. This requires a new approach to measuring and managing fluid cleanliness. Effective fluid management requires a process to:
- Identify when fluids are dirty
- Identify when fluids are clean
- Maintain records to show how the fluids are behaving over history
This site has created a process to measure machine fluid cleanliness (particle count) at each service, both when the machine enters for service and after the service is complete. All records are maintained in a central database with results trended for variation.

2.0 Best Practice Description
Measuring Fluid Cleanliness
All fluids on the mine site are regularly checked for cleanliness. This site uses the Pamas S-40 particle counter to take particle count measurements in all filtered machine compartments at each PM.

Pamas S-40 particle counter

Data Entry
All particle-counting records are stored and analyzed in a Microsoft Access database, created by Unatrac. Data entry is simple and efficient.
Key fields include:
- Machine ID
- Sample ID
- Machine hours
- Date
- Particle count
Lube and Hyd oils: particles >6 & >14 um
Fuel: particles >4 / >16 / >14 um

Particle Count Data Screen
Data entry is quick and convenient.

Fluids Sampled

New Oils
Due to the remote location and lack of infrastructure, all hydraulic and lube oils are delivered to the site in 1,000 liter, disposable plastic cubes. Samples are taken from each cube and at the dispensing point and the cleanliness level recorded.
Many new oils have large amounts of additives, which tend to clump together in clusters, which are large enough to be recorded as particles when using a laser particle counter. This is known as “additive interference”. The combination of contamination from the new plastic container and the effects of additive interference often result in the new oil exceeding the cleanliness target of ISO 16/13 for new oil. Trying to achieve the new oil cleanliness target by kidney looping multiple grades of oil in dozens of cubes is impractical. New oil cleanliness is achieved during oil changes, by kidney looping the system, after the new oil is in the machine.

Fuel
Fuel is checked on a weekly to daily basis for compliance with the ISO 18/16/13 standard. Both, the dealership, and the fuel supplier take the measurements. Regular non-conformance is recorded in the case of future frequent fuel system problems.

Machine Fluids
On-machine fluids are checked for cleanliness at every PM service. The process followed is as follows:
1. The machine enters the PM bay and an oil sample is taken and particle counted for all major systems (example. 785C - hydraulic, steering, transmission, rear axle).
2. If the ISO reading is above 18/15, then the system is kidney loop filtered. If the particle count is 18/15 or better, then the system does not have to be kidney looped. (A flow chart of the process is shown on the following page).
3. Before the machine is returned to service, an additional oil sample is taken and particle count performed.
4. Both before PM service and after PM service particle count reading are recorded in the database.
5. SOS is also performed and these readings are matched with the particle count readings.
6. Measurements are tracked over time and particle counts are observed.
Decisions to change the PM service activities are strongly influenced by particle counts.
On new and rebuilt components, the break-in process generates additional debris, which results in higher particle counts. Systems that measure higher than ISO 18/15 at the end of the PM period are kidney looped to 16/13 during the PM to accelerate the removal of break-in debris. When the system can maintain ISO 18/15 or better at the end of the PM period, the onboard filters are maintaining system cleanliness and kidney looping can be discontinued.
A sudden and significant increase in particle count or premature filter plugging indicates abnormal component wear. This triggers an immediate SOS sample and inspection.
Machines in the fleet have been fitted with Ultra-High Efficiency (UHE) filters on powertrain and hydraulic systems. These filters are capable of maintaining high levels of fluid cleanliness once break-in debris has been removed. Kidney looping at each PM is discontinued after the onboard filtration demonstrates the ability to maintain ISO 18/15 or better through the PM period. This results in better PM efficiency.
The process map below illustrates this logic.

Measurement & Recordkeeping Process Map

3.0 Implementation Steps
Fluid cleanliness measurement and recordkeeping is part of a larger fluid cleanliness management strategy in place at this site. A critical part of this strategy is to consistently measure and record particle counts.
This requires at least two portable particle counters on site. While great strides have been made in reliability and durability of portable particle counters, they are still lab instruments used in the field. Repair of these instruments requires they be shipped back to the manufacturer for several weeks. Back-up units must be available to continue to gather data on a daily basis.

4.0 Benefits
Effective measurement, recording and trending of particle count data provides a simple and powerful management tool to improve PM efficiency and identify abnormal wear or failure quickly.

5.0 Resources Required
Cost of a typical particle is approximately $10,000 USD. A minimum of two is required. The cost of training personnel to use the equipment, take samples and record data is minimal.

6.0 Supporting Attachments / References
Improving Component Durability – Fluid Cleanliness Management booklet
• This document explains additive interference, laser particle counting, fluid filter ratings, filter media, etc.
• Available in paper only. Caterpillar literature number: SEBF1020

7.0 Related Best Practices
0806-2.1-1000 Fluid Cleanliness Management
0806-2.1-1001 Measuring Oil Cleanliness

8.0 Acknowledgments
This Best Practice was written by:
Jeff Wolffe
CGM EAME Product Support
Wolffe_Jeffrey_S@cat.com
+41-22-849-4423

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Off-Board Fluid Filtration

1.0 Introduction
The performance expectations for components and systems on modern mining machines have grown rapidly in the past two decades. This has driven the design of hydraulic systems to operate at much higher pressures, and dramatically increased the load factor on drivetrain components.
The increased performance demands also increase the rate of abrasive wear and failure of components compared to older designs, which operated at lower load factors.

2.0 Best Practice Description

2.1 Debris
In order to increase durability, it is necessary to operate components and systems in much cleaner fluids throughout the life of the component. There are three sources of debris:

2.1.1 Assembly Debris
A large amount of debris is often present in machine systems when new machines are assembled. In the past, failure to remove this debris caused a high rate of system malfunctions and component failures at the factory and in early-hour operation. As a result, portable filter carts were designed for use in the factory to clean machine systems before machines were shipped. When used properly, these carts effectively removed assembly debris and cleaned systems to a factory ship target of ISO 18/15. This cleaning of systems prior to shipment dramatically reduced the incidence of early-hour problems.

2.1.2 Break-In Debris
There is a widespread misconception that nearly all system debris is from new machine assembly, and that once systems are cleaned properly, they stay clean. This is not true. Most components produce debris as a result of the normal break-in process. The length of the break-in process and volume of debris produced varies by system. A mining truck provides a good example of how systems vary.
Steering System
Steering systems essentially consist of a small piston pump, steering cylinders and a control valve. Once assembly debris is removed from this system, it produces very little break-in debris and normally stays clean with standard machine filtration.
Transmission
Transmission clutch discs, and gears produce moderate amounts of break-in debris. This process usually takes between 100-200 hours to complete. Even if the transmission were perfectly clean after assembly, break-in debris would still be produced.
Final Drive & Differential
The rear axle produces very large amounts of break-in debris from gears. This process may last up to 8,000 hours. This debris is almost all very small abrasive particles from the hardened gears.

2.1.3 Normal Wear Debris
After the break-in process is complete, components still produce microscopic wear particles, but at a much slower rate. The rate is largely affected by how many wear particles are already in the oil. If the oil is contaminated with a high number of abrasive particles, the normal component wear process is greatly accelerated. If the oil is very clean, the normal wear process is much slower, which significantly extends component life.
On-board machine filtration on most mining machines is not capable of maintaining high levels of fluid cleanliness necessary to maximize component life. As a result, portable factory filtration carts are used during PM’s and after system repairs. This practice has grown with the increase in MARC contracts and extended component life guarantees.

2.2 Off-Board Machine Filtration (Kidney Loop)
The use of off-board filtration carts started in the factory to remove assembly debris that was causing frequent production line and early-hour problems. The practice eventually migrated to dealers where the carts were initially used to clean systems after a major repair or component replacement. This later evolved into use of carts during PM intervals. Those dealers found that consistent use of the carts for several hours during PM removed large amounts of debris and helped to achieve and maintain a much better level of oil cleanliness.
There are four basic applications of filtration carts in dealer shops and mine sites:

2.2.1 New Machine Assembly:
Large mining machines are too big to ship fully assembled, so large components such as wheel groups are assembled in the field. It is impossible to maintain system cleanliness when major components are open to contamination during assembly. Even in systems that are shipped assembled (such as hydraulics) cleanliness levels on new machines often exceed the factory roll-off spec of ISO 18/15. This has caused great debate between dealers who claim the system arrived dirty and factory personnel who claim it left clean. There are three reasons for this:

System Not Cleaned Properly
In a few cases, the system cleanliness may exceed the pre-shipment specification, due to inadequate cleaning prior to shipment.
Variability in Particle Counters
Particle counters (whether lab or portable) basically shine a small laser beam through an oil sample and count the number and size of shadows caused by particles in the oil. They also count water droplets, air bubbles and large agglomerated particles oil additives. Inherent variability in both, the particle counter and the sample treatment process, may account for elevated readings of one to two ISO codes. This is problem is even more prevalent in the field use of portable particle counters where cleaning between samples and sample treatment techniques may vary widely. It is not uncommon (due to variability in the particle counter) to deliver varied results (readings) from the same oil sample.

Additive Interference
Some new oils contain large amounts of additives. Some of these additive molecules attract and form large clusters in systems where the oil is not be used (such as new systems). These clusters may get large enough appear as a debris particle to a particle counter, and cause the particle count to be higher than it actually is. On new machines, systems should be exercised 1-2 hours to break down these additive clusters before a relatively accurate particle count can be taken.

2.2.2 PM Intervals
Many dealers or customers who are interested in maximizing component life use filtration carts for the major systems during normal PM’s. It typically takes 10-15 minutes per system to connect the carts to each system (rear axle, transmission, hydraulics, steering) at the start of the PM. Carts are then allowed to run unattended for several hours while normal PM services are completed.

2.2.3 System Oil Changes:
A long-standing spec for new oil cleanliness has been ISO 16/13. With the increasing level of additives in the oil, filtering oil to this level has become increasingly difficult. In addition, not all sites can justify the cost of permanent recirculating filtration for new oil. A viable alternative is to fill the compartment with new oil and then install and use an off-board filter cart to achieve the desired cleanliness. Machine system contamination is not a problem since the filtration process occurs before the machine is started. It also has the added benefit of removing some system contaminants that would not otherwise be removed if only new clean oil was installed.

2.2.4 Major Repairs
When major components are replaced or systems are opened up for repair, filtration carts should be used to maximize system cleanliness. A leading cause of failure of rebuilt components is failure to clean the system before the new component is put back in service. This is especially true with catastrophic failures, where the system is contaminated with failure debris.

3.0 Implementation Steps
There are several criteria for the number and size of carts required.
Cart Size
Cart filter size and flow rate is determined by the capacity of the system being filtered. As a rule of thumb, the cart should be sized to filter the volume of the system 35 times in a reasonable period of time.
Oil Type
A different cart is required for each oil type. (Example: rear axle oil cannot be mixed with hydraulic oil)
Fleet Size

The number and model of machines being maintained determine the number of carts required. For medium and large fleets, two sets of carts are often required: one set for PM and one for repair. An inadequate number of carts often results in a cart being used for PM or repair and unavailable for use on another machine when needed.

Help with determining the correct number of carts needed, cart size and required tooling is available from the Caterpillar Service Tools Group or from the Marketing and Product Support Contamination Control Group.

Service Tools Group – contact Jim Balfanz, Balfanz_James_W@cat.com
Contamination Control Group – contact Dave Baumann, Baumann_David_L@cat.com

4.0 Benefits
Maintaining oil cleanliness for major components and machine systems increases both reliability and durability. Electro-hydraulic control valves, which are widely used in transmission controls and implement hydraulics, are very intolerant of microscopic, ferrous debris. Heavily loaded wheel and final drive bearings, as well as, duo-cone seals are also easily damaged by abrasive debris commonly found in new oil. Assuring the new oil is cleaned to the desired cleanliness level, and maintaining ISO 18/15 or better significantly reduces the number of contamination induced failures and repairs and significantly extends component life.

5.0 Resources Required
The number and size of filter carts required is determined by fleet size. Carts may be purchased through Caterpillar Service Tool Group, outside suppliers, or built by the dealer. Training for maintenance and operation personnel is also required so that they fully understand the function and importance of the use of filter carts.

6.0 Supporting Attachments
“Improving Component Durability” booklet set- form # SEBF1021.
Consists of one of each of the following:
Fuel Systems SENR9620
Final Drives and Differentials SEBF1015
Powershift Transmissions SEBF1016
Component R&I SEBF1017
Engines SEBF1018
Hydraulics SEBF1019
Managing Fluid Cleanliness SEBF1020

7.0 Related Best Practices
0808-2.10-1003 -On-board Fluid Filtration
0806-2.10-1000 -Managing Fluid Cleanliness

8.0 Acknowledgements
This Off-board Fluid Filtration Best Practice was authored by:
Dick Douglas
Market Consultant
Caterpillar Global Mining
Douglas_Richard_D@cat.com
1-309-675-5699

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