Product Overview

The 397-5704 hydraulic boom cylinder seal kit (also written 3975704) is an aftermarket rebuild set marketed for the boom cylinders of Caterpillar CAT backhoe loaders, principally the 416E, 416F, 420E, 420F, 430E, 430F, 432E and 434E models. IMPORTANT: 397-5704 is an aftermarket listing number, not a verified genuine Caterpillar OEM part number — it does not appear in the AVSpare genuine-Cat parts database (direct lookup returns no result), and at least one parts supplier (Bharat Genuine Parts) explicitly lists it as “BOOM SEAL KIT 397-5704 AFTERMARKET”. Aftermarket data associates it with the Cat KIT-HYDRAULIC CYLINDER SEAL family (cross-reference 521-2972 / 397-5181 seen in AVSpare data). DJF Seals supplies this kit factory-direct as an aftermarket replacement.

Verified Application

Boom (rear boom / backhoe) cylinder of CAT backhoe loaders — the boom position is consistently stated across supplier listings: Alibaba describes “3975704 Hydraulic Boom Cylinder Repair Seal Kit for CAT”, and a Russian construction-parts catalog (jcb-volvo.ru) lists 381-2732 / 397-5704 as a rear boom cylinder repair kit. The eight-model fitment list (416E, 416F, 420E, 420F, 430E, 430F, 432E, 434E) appears identically in several supplier listings (Alibaba, Mercado Libre, this page), which indicates a shared content lineage rather than independent per-model verification.

Replacement Scope

One boom-cylinder seal set per kit. This kit is a boom cylinder repair set — rod and piston sealing elements, wipers and wear guidance components as supplied. Because 397-5704 is an aftermarket number, always check that the kit matches your specific cylinder and machine serial before ordering; dimensions, pressure and temperature ratings should be requested from the supplier rather than assumed.

Fitment Verification

SUSPECTED IMAGE MISMATCH — MANUAL CHECK REQUIRED: the featured/og image attached to this page is named 397-3557-seal-kit.webp (file under /wp-content/uploads/2025/05/), which does not match the product part number 397-5704. The filename suggests a different part (397-3557). Please verify manually whether the image actually shows the 397-5704 kit. Per policy, the image src, file name and Alt have been left unchanged.

Model fitment: the eight-model list (416E/416F/420E/420F/430E/430F/432E/434E) is repeated verbatim across supplier listings (Alibaba family, Mercado Libre, DJF page) — treat it as claimed fitment, not independently verified per model. A Russian parts catalog (jcb-volvo.ru) lists 381-2732 / 397-5704 in the context of CAT 428E, 432E, 434E and 444E backhoe loader hydraulics — 428E and 444E are not in the eight-model list, another sign that aftermarket fitment data for this number is not uniform. CONFLICT NOTE: no genuine Cat dealer database entry for 397-5704 was found (AVSpare lookup: not found), so genuine-OEM fitment claims should not be made.

Factory Inspection & Packing

Every DJF seal kit is checked against its part number and application list before packing: seal elements are inspected for visible defects, counted against the kit list, and packed in sealed PE bags with a parts label. Kits are then packed into export cartons for warehouse or direct shipping. OEM/ODM branding and custom packaging are available on request. Kits are shipped as aftermarket replacement parts.

Wholesale Ordering

DJF Seals is the factory, so wholesale buyers deal directly with the manufacturer. We supply the 397-5704 and other backhoe-loader seal kits at factory-direct pricing, with mixed orders supported. Send your inquiry with quantity to [email protected] or [email protected] — our sales team responds within one business day with a quote, lead time and shipping options.

MOQ

MOQ: 5 kits.

FAQ

Is 397-5704 a genuine Caterpillar part number?

We found no evidence that 397-5704 is a genuine Cat OEM number — it is absent from the AVSpare genuine-Cat database and is sold as an aftermarket kit. Treat it as an aftermarket listing number and check fitment against your cylinder before purchase.

Why is the product image named 397-3557?

The image file attached to this page is named 397-3557-seal-kit.webp, which does not match part 397-5704 — a suspected mismatch that needs a manual check. The image src, file name and Alt have intentionally not been changed.

What is the MOQ and how do I order?

MOQ: 5 kits. Email [email protected] or [email protected] with your quantity and shipping address for a factory-direct quote.