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Introduction
Revision | Summary of Changes in SEHS8630 |
24 | Updated Effectivity |
23 | Updated Effectivity |
22 | Updated Effectivity |
21 | Updated Effectivity |
© 2019 Caterpillar All Rights Reserved. This guideline is for the use of Cat dealers only. Unauthorized use of this document or the proprietary processes therein without permission may be violation of intellectual property law. Information contained in this document is considered Caterpillar: Confidential Yellow.
This Reuse and Salvage Guideline contains the necessary information to allow a dealer to establish a parts reusability program. Reuse and salvage information enables Caterpillar dealers and customers to benefit from cost reductions. Every effort has been made to provide the most current information that is known to Caterpillar. Continuing improvement and advancement of product design might have caused changes to your product which are not included in this publication. This Reuse and Salvage Guideline must be used with the latest technical information that is available from Caterpillar.
For questions or additional information concerning this guideline, submit a form for feedback in the Service Information System. To address an urgent issue, use the following resources to communicate your request to Caterpillar Repair Process Engineering:
- Caterpillar Dealer Technical Communicator
- Dealer Solution Network
- Caterpillar Technical Representative
- Knowledge Network
Canceled Part Numbers and Replaced Part Numbers
This document may not include canceled part numbers and replaced part numbers. Use NPR on SIS for information about canceled part numbers and replaced part numbers. NPR will provide the current part numbers for replaced parts
Summary
This instruction provides the necessary procedure for measuring the cylinder bore to determine if the dimension is inch or metric. This instruction helps decide whether the bore requires standard or oversize seals and the procedure for installing the seals.
Since there is the possibility that the cylinder bore could have been honed oversized, determine a tube bore size prior to installing new seals. Also, many cylinders from Caterpillar and other suppliers are designed using metric dimensions. Knowing if the bore is inch or metric, new, standard, or oversize when selecting and installing seals is important.
If you are not certain of the bore size, examine the tube for one or more of the following:
- A plate attached to the OD of the tube near the open end. The plate will have raised characters indicating the oversize amount along with an "0R" part number.
- Characters stamped into the casting at the closed end of the tube that indicates the oversize amount.
You will have to measure the bore of the cylinder if the previous two methods of identification are not present.
Important Safety Information
Illustration 1 | g02139237 |
Work safely. Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools to perform these functions properly. Safety precautions and warnings are provided in this instruction and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. Therefore, the warnings in this publication and the warnings that are on the product are not all inclusive. If a tool, a procedure, a work method, or operating technique that is not recommended by Caterpillar is used. Ensure that the procedure is safe for you and for other people to use. Ensure that the product will not be damaged or be made unsafe by the operation, lubrication, maintenance, or the repair procedures.
Improper operation, lubrication, maintenance or repair of this product can be dangerous and could result in injury or death. Do not operate or perform any lubrication, maintenance or repair on this product, until you have read and understood the operation, lubrication, maintenance and repair information. |
Safety precautions and warnings are provided in this manual and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons.
The hazards are identified by the safety alert symbol which is followed by a signal word such as danger, warning, or caution. The "WARNING" safety alert symbol is shown below.
Illustration 2 | g00008666 |
This safety alert symbol means:
Pay attention!
Become alert!
Your safety is involved.
The message that appears under the safety alert symbol explains the hazard.
Operations that may cause product damage are identified by "NOTICE" labels on the product and in this publication.
Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. The safety information in this document and the safety information on the machine are not all inclusive. Determine that the tools, procedures, work methods, and operating techniques are safe. Determine that the operation, lubrication, maintenance, and repair procedures will not damage the machine. Also, determine that the operation, lubrication, maintenance, and repair procedures will not make the machine unsafe.
The information, the specifications, and the illustrations that exist in this guideline are based on information which was available at the time of publication. The specifications, torques, pressures, measurements, adjustments, illustrations, and other items can change at any time. These changes can affect the service that is given to the product. Obtain the complete, most current information before you start any job. Caterpillar dealers can supply the most current information.
Safety
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 steering system. |
Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the attachments have been lowered, oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand. |
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, PERJ1017, "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. |
References
Media Number | Title |
NENG2500 | “Dealer Service Tool Catalog” |
Tooling and Equipment
Part Number | Part Description |
Quick Cure Primer (PUMP BOTTLE) | |
Bearing Mount Compound (50-ML TUBE) |
Determining the Bore Size
First measure the cylinder bore and convert the measured diameter to inches or metric. This procedure will help you to determine whether the bore is inch or metric, or if the cylinder is using standard or oversized seals. Refer to Table 4 and the following process for determining bore sizes.
English (Inch) Cylinders
- The bore diameters of English (inch) cylinders increase in size by nominal values of 0.250 inch. (Examples: 7 inch, 7.25 inch, 7.5 inch, 7.750 inch)
- New English (inch) cylinders from the factory have bores that are no larger than 0.005 inches larger than the nominal size. (Examples: 7.005 inches, 7.255 inches, 7.505 inches, 7.755 inches)
- New English (inch) cylinders can be honed up to 0.010 inches over the new (nominal) size and still use standard-size seals. (Examples: 7.010 inches, 7.260 inches, 7.510 inches, 7.760 inches)
- English (inch) size cylinders can be honed 0.030 inches over the standard nominal size and be resealed by using oversized seals. (Examples: 7.030 inches, 7.280 inches, 7.530 inches, 7.780 inches)
- Once the cylinder has been honed 0.030 inches over the standard nominal size, the cylinder can be honed an additional 0.010 inches and use oversized seals. Once the bore size has reached 0.040 inches over the standard nominal size, the cylinder must be retubed or replaced.
Note: Check the availability of oversized seal kits before honing your cylinder bore oversized.
Metric Cylinders
- The bore diameters of metric cylinders increase in size by nominal values of 5 mm or 10 mm. (Examples: 115 mm, 120 mm, 130 mm, 140 mm)
- New metric cylinders from the factory have bores that are no larger than 0.10 mm larger than the nominal size. (Examples: 115.10 mm, 120.10 mm, 130.10 mm, 140.10 mm)
- New metric cylinders can be honed up to 0.254 mm over the new (nominal) size and still use standard-size seals. (Examples: 115.254 mm, 120.254 mm, 130.254 mm, 140.254 mm)
- Metric size cylinders can be honed 0.762 mm over the standard nominal size and be resealed by using oversized seals. (Examples: 115.762 mm, 120.762 mm, 130.762 mm, 140.762 mm)
Note: Check the availability of oversized seal kits before honing your cylinder bore oversized.
Bore Sizes Chart
Inch and Metric Bore Sizes | |||
---|---|---|---|
Inch Bore Size | Metric Bore Size | |
|
2.250 inches | - | |
|
2.500 inches | - | |
|
2.750 inches | - | |
|
3.000 inches | - | |
|
- | 80 mm | |
|
3.250 inches | - | |
|
3.500 inches | - | |
|
- | 90 mm | |
|
3.750 inches | - | |
|
- | 100 mm | |
|
4.000 inches | - | |
|
4.250 inches | - | |
|
- | 110 mm | |
|
4.500 inches | - | |
|
- | 115 mm | |
|
- | 120 mm | |
|
4.750 inches | - | |
|
- | 125 mm | |
|
5.000 inches | - | |
|
- | 130 mm | |
|
5.250 inches | - | |
|
5.500 inches | - | |
|
- | 140 mm | |
|
- | 150 mm | |
|
6.000 inches | - | |
|
6.250 inches | - | |
|
- | 160 mm | |
|
6.500 inches | - | |
|
- | 170 mm | |
|
7.000 inches | - | |
|
- | 180 mm | |
|
7.250 inches | - | |
|
7.500 inches | - | |
|
- | 190 mm | |
|
7.750 inches | - | |
|
- | 200 mm | |
|
8.250 inches | - | |
|
- | 210 mm | |
|
8.500 inches | - | |
|
- | 220 mm | |
|
9.250 inches | - | |
|
10.00 inches | - | |
|
10.250 inches | - | |
|
10.500 inches | - | |
|
11.000 inches | - | |
|
11.500 inches | - | |
|
12.250 inches | - | |
|
12.500 inches | - | |
|
13.000 inches | - | |
|
13.250 inches | - | |
|
14.250 inches | - | |
|
14.750 inches | - | |
|
16.750 inches | - | |
|
Measuring Examples
- The measured bore size is
158.93 mm (6.257 inch) in diameter. This bore is not metric because this measurement is not close to the standard or oversized metric diameter as found in the chart. This cylinder is English (inch) with a standard bore size of 6.250 inches. The bore is oversized 0.007 inches and the cylinder is not new because the bore is more than 0.005 inches larger than the standard (nominal) size. This cylinder can still be honed up to 0.003 inches more in diameter and use the standard seals. - The measured bore size is
165.86 mm (6.530 inch) .This bore is not metric because this measurement is not close to the standard or oversized metric diameter as found in the chart. This cylinder is English (inch) with a standard bore size of 6.500 inch cylinder that has been honed exactly 0.030 inches oversized. This cylinder will still use the oversized seals. - The measured bore size is
120.76 mm (4.754 inch) . This bore could be metric because the bore is exactly0.76 mm (0.030 inch) oversized for a metric cylinder. However, this bore is a new English (inch) bore. The bore is less than 0.005 inches larger than the standard nominal bore size of 4.750 inches. This bore can be honed up to 4.760 inches and still use standard seals. - The measured bore size is
160.02 mm (6.300 inch) . This bore is metric because the bore diameter is too large to be an oversized English (inch) cylinder and too small to be a new English (inch) cylinder. Also, this bore is less than 0.10 mm larger than the standard (nominal) 160 mm bore.
Head Seal Locations
Illustration 3 | g01640536 |
Threaded gland with standard head seal |
The head seal for the oversize threaded gland cylinder is the standard O-ring and back-up ring (1).
Illustration 4 | g01640543 |
Threaded crown with oval seal |
The head seal for the oversize threaded-crown cylinder is an oval cross-section seal (2). The seal is located in the lead-in chamfer at the open end of the cylinder. The O-ring and back-up ring groove (A) in the head is left empty
Illustration 5 | g01640566 |
Bolted-Head Cylinder |
Formerly, the head seal for the oversize bolted-head cylinder was the same oval seal (6) that is used in an oversize threaded-crown cylinder. The oversize bolted-head cylinder is now sealed at the head joint (3) by an O-ring (4). This O-ring (4) provides a more effective seal than the oval head seal. The groove (5) for the stock seal is left empty.
Rod Seal Installation
Illustration 6 | g01644830 |
- Install buffer seal (2) by hand. The sealing lip of the buffer seal should face the pressure side of the cylinder. The seal will take on a kidney shape during installation. Then, install the back-up ring (3). The backup ring should be installed closest to the rod eye end. Make sure that you do not twist the back-up ring.
- Next, install the U-cup seal (6) next. Install the U-cup seal by hand. The "U" of the U-cupped seal should face toward the piston.
- The head wear ring (1) is rigid and the wear ring is split to aid in assembly. Compress head wear ring (1) and slide the head wear ring down into position until the wear ring snaps into place.
- Use the following procedure to install wiper seal (8).
Note: The wiper seal (8) can be a press-in style that uses a metal shell or the wiper seal can be a snap-in style. The snap-in style does not require the use of bearing mount compound.
- Scuff the surface of the counterbore in the head as well as the outside diameter of the wiper seal's (8) metal shell with emery cloth.
- Clean the counterbore in the head and the outside diameter of the wiper seal metal shell with 6V-1541 Quick Cure Primer. Clean the counterbore and the metal shell until neither of the components discolor a clean white towel.
Note: The metal shell of the wiper seal is coated with a corrosion inhibitor. This coating may prevent proper bonding of the wiper seal to the cylinder head if the inhibitor is not removed. After cleaning, do not touch the counterbore or the metal shell because the oil from your fingers may prevent a good bond. Handle the seal by the lip only.
- Apply 6V-1541 Quick Cure Primer on the counterbore and the metal shell. Allow the primer to dry. The primer will dry in approximately 30 seconds.
- Apply 7M-7456 Bearing Mount Compound evenly, but do not apply the Bearing Mount Compound excessively. Apply Bearing Mount Compound to the counterbore and to the metal shell. Do NOT allow the Bearing Mount Compound to contact the sealing lip.
- Press wiper seal (8) into the cylinder head. Make sure that the marking "THIS SIDE OUT" on the seal (8) is toward the rod end. Ensure that the seal is firmly seated against the bottom of the counterbore. Wipe away any excess Bearing Mount Compound. Allow Bearing Mount Compound to dry for 15 minutes before assembling the hydraulic cylinder.
- Use the following procedure to install wiper seal (8).
- Assemble the oval seal (7) or the O-ring (4) and back-up ring (5), depending on the application.
Note: The O-ring (4) should always face the pressure side of the cylinder and back-up ring (5) should be located on the rod eye side.
Piston Seal Installation
Illustration 7 | g01646458 |
- Install expander ring (3) first. Do not twist the expander ring during installation. Use a small screwdriver to work the expander ring around piston (2) and into the groove.
- Install piston seal ring (4) on top of expander ring (3). Seal ring (4) is split and can be installed by hand.
- The piston wear ring (1) is rigid and is split to aid in assembly. Expand wear ring (1) and slide over piston (2) until wear ring (1) snaps into position.
Installation of the Head onto the Rod
Illustration 8 | g01646675 |
- Lubricate the rod (1) and the seals with clean hydraulic oil.
- Install a seal guide (2). The seal guide (2) is a cone shaped tool that is used to open the seals that are located in the head. The seal guide ensures that the seals will slide onto the rod without damage. The seal guide also serves to align the seals.
- Push the head (3) over the rod by using one quick motion.