Water Pressure Sensor 881879T26 – Fits Mercury Verado Outboards

Water Pressure Sensor 881879T26 – Fits Mercury Verado Outboards

Vendor: JLM Marine
Availability: In Stock
Product Type: Sensor
$149.77
$149.77
Subtotal: $149.77

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Water Pressure Sensor 881879T26 – Fits Mercury Verado Outboards

Water Pressure Sensor 881879T26 – Fits Mercury Verado Outboards

$149.77
Description

How to Match This Part

This aftermarket water pressure sensor replaces Mercury Marine 881879T26 and the earlier numbers it supersedes, 881879A19 and 881879A20. On Verado powerheads it sits in the port cylinder block group and is fed by a small pressure tube from the cooling circuit, where it reports raw-water pressure to the SmartCraft system so the engine can warn you before an overheat becomes engine damage. Every unit is brand new production — not remanufactured and not rebuilt from a used core.

Match this part in this order:
1. Serial number — Mercury outboards: plate on the transom bracket or cowl identification plate
2. Model family and horsepower — for example Verado 4-cylinder 150, Verado 6-cylinder 250, Pro Verado 300
3. Number stamped on the sensor you remove, then compare the thread, connector, and overall shape with the product images

Identify the correct sensor by form as well as by number. The unit uses a threaded metal pressure-port fitting, a moulded connector housing with a locking tab for the engine harness, and an outlet spigot for the pressure tube. If your original sensor looks different, uses a different connector, or carries an unrelated Mercury number (for example a MAP sensor), do not use this part even if the horsepower overlaps.

Part Number Cross-Reference

Use these verified numbers to confirm you have the correct water pressure sensor. Brand names and OEM numbers are for identification only.

Type Brand Part Number Notes
OEM Mercury Marine 881879T26 Current OEM water pressure sensor assembly
OEM Mercury Marine 881879A19 Earlier number; superseded by 881879T26
OEM Mercury Marine 881879A20 Earlier number; superseded by 881879T26
Aftermarket WSM 778-120 Aftermarket water pressure sensor for Verado applications

This is an aftermarket part manufactured by JLM Marine. It is not sold as a genuine Mercury Marine or Mariner component.

Compatible Engine Models

Confirm your engine model and serial number in the table below. Mercury changed this sensor number during several production runs, so the serial range is the decisive check. For Mercury owners: Mercury Serial Number Guide and Mercury Parts Diagrams. Mariner-badged engines that use the same Mercury OEM number are covered the same way — always match the number on the sensor you remove.

Engine Family HP Serial Number Range Notes
Verado 4-Stroke, 4 Cylinder 135, 150, 175 0P419487 and up (see serial breaks for your model) Via 881879A20 supersession to 881879T26
Verado 4-Stroke, 4 Cylinder 200 0P514869 and up Via 881879A20 supersession to 881879T26
Verado 4-Stroke, 6 Cylinder 200, 225, 250, 275 0T980000 THRU 1B226999 Via 881879A19 supersession to 881879T26
Verado 4-Stroke, 6 Cylinder 200, 225, 250, 275 0P409357 THRU 1B517433 Via 881879A20 supersession to 881879T26
Verado 4-Stroke, 6 Cylinder 200, 225, 250, 275, 300 0P520553 THRU 2B144122; 1B517434 THRU 2B144122; 2B144123 and up Direct 881879T26 catalog applications
Pro Verado 4-Stroke, 6 Cylinder 200, 250, 300 2B034840 and up (200); 1B830170 and up (250/300); later 2B144123 and up Direct 881879T26 catalog applications
Verado / Pro Verado 4-Stroke, 6 Cylinder 350, 400 2B141124 and up (350 Pro / 400); 2B141617 and up (350) Direct 881879T26 catalog applications
350SCi Verado 350 1B716557 THRU 2B143542 Direct 881879T26 catalog application
Pro XS 3.0L DFI 225, 250 1B426561 and up (earlier via A20); 1B752547 and up (T26) Confirm number on removed sensor
XS / Sport XS DFI 225, 250, 300 1E001867 and up (model-specific breaks apply) Via 881879A20 supersession; confirm OEM number

If your serial number sits near a range boundary, confirm the number stamped on the sensor you are removing before ordering.

Technical Specifications

Specification Value
Part type Water pressure sensor assembly
Primary OEM number replaced 881879T26
Superseded numbers covered 881879A19, 881879A20
Engine brands Mercury; Mariner where the same OEM number applies
Engine families Verado 4-cylinder and 6-cylinder four-stroke, Pro Verado, 350SCi, selected Pro XS / XS DFI
Mounting location Port cylinder block group; fed by the cooling-circuit water-pressure tube
Electrical interface Moulded plug-in connector with locking tab for the engine harness
Condition Brand new production unit, not remanufactured or rebuilt

Installation Guide

  1. 1Shut the engine down, let it cool, and disconnect the negative battery cable before touching any sensor or harness connector.
  2. 2Remove the cowl and locate the water pressure sensor in the port cylinder block area, where the small pressure tube from the cooling circuit meets the sensor port.
  3. 3Press the locking tab and unplug the harness connector, then release the retaining clip and separate the pressure tube from the sensor. Expect a small amount of residual water.
  4. 4Unscrew the old sensor with a correctly sized wrench on the hex flat only. Never apply force to the plastic connector housing or the outlet spigot.
  5. 5Clean the threads and sealing face, compare the new sensor with the old one for identical thread, connector, and spigot layout, then fit the new sensor and tighten to the torque given in your Mercury service manual.
  6. 6Reconnect the tube and harness plug, reconnect the battery, run the engine on a flushing supply or in the water, and confirm that the SmartCraft display or gauge shows a stable water-pressure reading with no leaks around the fitting.

Note: Professional installation is recommended for SmartCraft cooling sensors.

Troubleshooting & FAQ

How do I confirm this fits my engine? +

Start with the serial number on your Mercury outboard and locate it in the compatible engine models table. Then confirm the model family and horsepower, and finally compare the number printed on the sensor you are removing with 881879T26, 881879A19, or 881879A20. If all three agree and the physical form matches, the part is correct for your engine.

My original sensor is marked 881879A19 or 881879A20. Can I still use this one? +

Yes. Mercury superseded both 881879A19 and 881879A20 to 881879T26. This aftermarket sensor is built to replace that current number, so an engine that originally left the factory with either earlier number is served by this part when the physical form matches.

What are the symptoms of a failing water pressure sensor? +

Typical signs are an erratic or blank water-pressure reading on the SmartCraft display, a low water-pressure warning while the telltale stream and cooling flow look normal, or a reading that drops to zero as soon as the engine warms up. Before replacing the sensor, check the pressure tube and fitting for salt blockage or splits — a restricted tube produces the same symptoms.

Is this an OEM or aftermarket part? +

This is an aftermarket replacement manufactured by JLM Marine. It is not a genuine Mercury Marine part. OEM and aftermarket numbers are listed only for cross-matching.

Important Notes

  • Verify that the product images and the number on your original sensor match 881879T26, 881879A19, or 881879A20, including thread, connector housing, and outlet spigot. If anything differs, do not proceed even if your engine model appears in the table.
  • This is an aftermarket replacement and is not a genuine Mercury Marine OEM component.
  • Every unit is brand new. We do not supply remanufactured or rebuilt sensors for this listing.
  • Tighten the sensor using the hex flat only and follow the torque value in your Mercury service manual. Over-tightening or gripping the plastic housing can crack the body and cause a leak.
  • Professional installation is recommended for SmartCraft cooling sensors.

Why Choose JLM MARINE?

  • Precision Fit: Cross-referenced to Mercury 881879T26 (and superseded 881879A19 / 881879A20) for the Verado applications listed above.
  • Quality Control: Each batch is inspected for dimensional consistency and workmanship.
  • Direct from Manufacturer: Aftermarket marine sensors engineered for reliable cooling-system pressure feedback on Mercury Verado outboards.
Shipping

We can ship to virtually any address in the world with free shipping available for most regions.

For our typical US and Canadian customers , our shipping timeframes are as follows:

  • Amazon FBA: orders will be delivered within 1-5 business days after placing the order (during certain special periods such as major promotions, Christmas, etc., the delivery time of Amazon FBA may be affected).
  • US warehouse shipment: orders will be delivered within 5 days after placing the order.
  • China warehouse shipment: orders will be delivered about 12 days after placing the order.

When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.

Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.

About JLM Marine

Founded in 2002, JLM Marine has established itself as a dedicated manufacturer of high-quality marine parts, based in China. Our commitment to excellence in manufacturing has earned us the trust of top marine brands globally.

As a direct supplier, we bypass intermediaries, which allows us to offer competitive prices without compromising on quality. This approach not only supports cost-efficiency but also ensures that our customers receive the best value directly from the source.

We are excited to expand our reach through retail channels, bringing our expertise and commitment to quality directly to boat owners and enthusiasts worldwide.

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