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Most orders ship within 1–2 business days via UPS. Larger equipment ships via freight carrier, and customers can use the shipping estimator on the product page for a location-specific quote. Local pickup is also available at the Fairfield, IL facility, typically ready within 4 hours.

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MRO Exchange accepts all major credit cards, PayPal, and Shop Pay. Purchase order and wire transfer payment is also available, with payment due prior to shipment. Custom terms are available for established accounts.

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Haldex Air Over Hydraulic Brake Actuator Assembly A840

$1,300.00 USD

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✓ 30-day returns on every item — return policy

ConditionSurplus - Untested MPNA840 Stock #0526-02530

30-day returns on every item. Photos reflect the actual item’s current condition — see our return policy and condition guide.

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Used in heavy-duty truck and trailer air-over-hydraulic brake systems, this assembly combines a Haldex SC12 Type 12 service brake chamber with a cast iron master cylinder body to convert compressed air pressure into hydraulic braking force. The Haldex SC12 air chamber features a powder-coated steel housing, an orange alert stroke indicator, a self-piloting dust shield, and air port threads of 3/8-18 NPTF with a maximum rated air pressure of 150 PSI. The diaphragm chamber casting reads 12SC12 with date code 099A18A. The cast iron master cylinder body is cast and machined in the USA, with casting number FE51033 visible on the body. The assembly is mounted on a heavy gold zinc-coated steel bracket with welded hardware. This type of air-over-hydraulic actuator assembly is commonly used on medium and heavy-duty commercial vehicles, vocational trucks, and trailers where the towing vehicle supplies compressed air to activate hydraulic wheel brakes. Cross-references for the Wagner-style power cluster family include A840, AF840, A838, AF838, and A839. The cast iron cylinder body shows surface oxidation and patina consistent with storage or prior installation. The Haldex SC12 chamber presents in cosmetically sound condition. Serial and casting markings are legible. MPN confirmed from casting: FE51033. Verify fitment and pressure ratings against your specific application before installation.

Stock # 0526-02530

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Shipping & Handling

Most orders ship within 1–2 business days via UPS, but expedited same-day handling is available as an add-on to orders in cart. Larger equipment ships via freight carrier. Use the shipping estimator above for a location-specific quote. Local pickup is also available at our Fairfield, IL facility, typically ready within 4 hours.

Returns & Condition

All items are sold as-described based on the photos and condition listed. If an item arrives differing from its description, it may be eligible for return or refund. See our full condition guide for details on our grading terms.

Payment Options

We accept all major credit cards, PayPal, and Shop Pay. Purchase order and wire transfer payment is also available by selecting "Purchase Order / Wire Transfer" at checkout. Payment is due prior to shipment. Contact us for custom terms on established accounts. Tax exemptions are honored if proper documentation is provided.