Caterpillar Excavator Seal Kits
Find aftermarket replacement hydraulic seal kits for Caterpillar excavators, including boom, stick/arm, bucket, blade and other cylinder applications. Fujis Seal organizes this collection so equipment owners, repair workshops and parts buyers can research the correct kit by Caterpillar/CAT machine model, OEM/reference part number, cylinder position, rod diameter and bore diameter. Listings cover commonly serviced Caterpillar excavator families such as 303.5, 307, 311, 312, 315, 320, 322, 325, 336 and 365 series.
Caterpillar Excavator Hydraulic Cylinder Seal Kits
Excavator seal kits are application-specific. A boom cylinder, stick/arm cylinder and bucket cylinder on the same machine normally use different sealing arrangements, and fitment can vary by serial-number range or cylinder group. For the most reliable selection, use the complete machine and component information rather than the excavator model alone.
Depending on the application, a hydraulic cylinder seal kit may include rod seals, piston seals, wiper seals, O-rings, backup rings, wear rings and guide elements. Exact kit contents and materials vary by product, so check the individual listing before installation.
How to Identify the Correct Caterpillar Excavator Seal Kit
Before ordering, compare as many of the following identifiers as possible:
- Machine model: confirm the complete Caterpillar/CAT excavator model.
- Serial number: important when a model family uses different cylinder versions.
- Cylinder position: boom, stick/arm, bucket, blade or another hydraulic function.
- OEM/reference part number: the preferred starting point when available.
- Rod and bore dimensions: useful as a secondary fitment check.
- Photos and markings: cylinder tags, old seal markings and package labels can support cross-reference research.
Part-number matching is generally more reliable than dimensions alone. Similar rod and bore sizes can still use different seal profiles, grooves or internal components.
Common Caterpillar Excavator Seal Kit Applications
Boom cylinder seal kits service the cylinders that raise and lower the boom. Stick or arm cylinder seal kits are used for the dipper/arm function, while bucket cylinder seal kits control bucket curling and dumping. Selected compact excavators may also use blade cylinder kits. Always match the kit to the exact cylinder position.
Part Number, Model and Dimension Cross-Reference
Use the Caterpillar/CAT reference number when available, then confirm the machine model and cylinder position. Rod and bore dimensions are valuable for verification, especially when the original number is incomplete or unreadable. Our guide to identifying the correct excavator seal kit explains the recommended identification sequence, and our hydraulic cylinder seal kit measurement guide covers rod and bore measurement.
Fitment Support from Fujis Seal
If you cannot find the required kit, contact Fujis Seal with the machine model, serial number, cylinder position, OEM/reference number, photos and available dimensions. Our support team can compare the supplied information with application and cross-reference data before you order.
Caterpillar Excavator Seal Kit FAQs
Are boom, stick and bucket cylinder seal kits interchangeable?
No. These cylinders usually have different dimensions and sealing arrangements. Select the kit for the exact cylinder position and machine application.
Does one seal kit fit every machine in the same Caterpillar model series?
Not necessarily. Fitment can vary by serial-number range, cylinder group and equipment configuration.
Can I identify a kit without an OEM/reference part number?
Often, yes. The machine model, cylinder position, serial number, photos and accurate rod and bore dimensions can help narrow the application, but more complete information gives a more reliable match.
Are these genuine Caterpillar parts?
Unless an individual listing expressly states otherwise, products in this collection are aftermarket replacement seal kits supplied by Fujis Seal. Caterpillar and CAT names and reference numbers are used for compatibility and product identification only.
Caterpillar and CAT are trademarks of their respective owner. They are used on this site for compatibility and product-identification purposes only and do not imply manufacturer endorsement or affiliation.
