New 5B3718 Seal O Ring Replacement suitable for Caterpillar Equipment
- New Seal O Ring Replacement suitable for Caterpillar Equipment
- Made to USA Specification
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HOW WE GUARANTEE, EXACT FIT
Before shipping your order, we use CAT SIS to ensure
this part is the exact fit for your equipment.
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Purchase with confidence because this part includes a
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Description for 5B3718 Seal O Ring
â–¶Specification for 5B3718 Seal O Ring
â–¶Exact Fit Guarantee for 5B3718 Seal O Ring
â–¶| Dimensions | 1.18x1.18x0.20 |
|---|
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Shaun (Arizona, USA)100%The Double Order Catastrophe
My co-worker placed an order and wasn't sure it went through online. I later placed the same order thinking the previous order didn't go through. To my surprise both orders went through, and I needed to cancel one of the orders. I called and spoke with someone who instructed me someone would contact me about the situation. I was contacted by Misty and she said she would do her best to cancel one of the orders but not sure if she could because they were next day orders. A small tome later I received an email saying she was able to cancel one of the orders. Thank you to Misty and the entire Propel Parts Team. Greatly appreciated!! -
John Ward (Texas, USA)100%Very helpful. Every question or request I had was answered quickly. I didn't have a parts book for my excavator but that was no problem for them. If you need parts for your Cat, give them a shot.
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JOSH CAUGHRAN (Illinois, USA)100%Steven & Propel Parts were a huge help! We were able to place a large order and get it shipped out same day to avoid a line down situation for a customer due to a lost component. The order was even submitted after the 3pm cutoff for same day shipments and we got it the next morning!
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Delwyn Vince Chiong (Philippines)100%Propel Parts provided quality parts for my Caterpillar needs at a very fair price. Shipping to my international location was very fast. took about a week for the parts to get here. Seller is also responsive with my inquiry.
Thanks again -
Dylan Danek (Texas, USA)100%Awesome service prices and quality parts
Frequently Asked Questions
What is the Caterpillar O-Ring 5B3718 used for?
The 5B3718 is an O-ring seal used in Caterpillar equipment to create fluid-tight connections in hydraulic fittings, engine ports, and fluid lines. It prevents leaks in both static and low-speed dynamic sealing environments where the specific dimensions of this O-ring match the required joint geometry.
Which Caterpillar machines use the 5B3718 O-Ring?
The 5B3718 is used across multiple Caterpillar equipment models in various sealing applications. For model-specific compatibility, check your parts manual or reach out to Propel Parts for help verifying fitment.
Is the 5B3718 a high-quality aftermarket seal?
Yes. The 5B3718 O-ring from Propel Parts is a premium aftermarket replacement that meets or exceeds OEM specifications for material composition, hardness, and dimensional tolerances. It provides the same reliable sealing performance as the original Caterpillar O-ring.
How do I identify the correct O-ring if my part number is worn off?
Measure the O-ring using a caliper ??? record the inner diameter and cross-section (thickness). You can then cross-reference these dimensions against Caterpillar O-ring charts or contact Propel Parts with your equipment model and the assembly/location information to help identify the correct replacement.
What lubricant is recommended when installing the 5B3718 O-Ring?
Use a small amount of the system fluid ??? clean hydraulic oil for hydraulic applications or clean diesel for fuel system applications ??? to lightly coat the O-ring before installation. This reduces friction and prevents tearing during seating, without compromising the seal's chemical compatibility.
How do I prevent twisting an O-ring during installation?
Apply lubricant evenly, stretch the O-ring gradually and symmetrically into the groove, and avoid rolling it in from one end. After seating, visually inspect the O-ring to ensure it is evenly positioned in the groove without any visible twisting or uneven cross-section. A twisted O-ring will leak even if the fitting is properly torqued.
Where can I find more seals and gaskets for Caterpillar equipment?
Propel Parts offers thousands of sealing components for CAT machines. Browse the complete seals and gaskets for heavy equipment category to find O-rings, oil seals, metal face seals, and complete gasket kits for your equipment's specific needs.

We know equipment downtime costs money, so fast and reliable shipping is a priority at Propel Parts. Orders placed on weekdays before 3:00 PM ET typically ship the same day, with expedited delivery options available for many locations when time is critical.
We ship across the U.S., Canada, and over 130 countries worldwide, helping customers keep machines running wherever they operate. Available shipping methods and delivery estimates are shown at checkout so you can select the option that best fits your timeline.
Tracking information is emailed within 24–48 hours after your order is processed, giving you full visibility from dispatch to delivery and peace of mind that your parts are on the way.

Our refund policy is simple. We offer a 30-day, no-hassle return policy, and we make every effort to provide the best service and highest-quality parts possible. If you’re not fully satisfied with your purchase, you may return it within 30 days for a refund. Full details are available on our Returns Policy page.

Buy with confidence. All parts from Propel Parts are covered against material or manufacturer defects for 12 months from the original invoice date. We stand behind every part we sell, so you can count on reliable performance and dependable support. Full details are available on our Warranty Policy page.
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