Sierra Oil Pressure Sender 18-5899, Replaces Mercury Marine 34623/90806 and Crusader 700425, 80 PSI

The Sierra 18-5899 is an 80 PSI oil pressure sender built for marine engines, providing the electrical signal that drives an oil pressure gauge on the helm. It uses a 1/8 inch 27 NPT thread for installation into the engine block or oil gallery and a 10-32 stud terminal for connecting the gauge wiring, making it a direct, no-modification swap for the senders it cross-references. Construction is aluminum or nickel, giving the sender the corrosion resistance needed to hold up in a marine engine compartment over repeated heat cycling. It is a universal fit sender, designed to work with 80 PSI electric oil pressure gauges rather than being tied to one specific gauge brand.

This sender directly cross-references Mercury Marine 34623 and Mercury Marine 90806, as well as Crusader 700425, so it is a straightforward replacement wherever one of those part numbers is called for. Because the thread size, pressure range, and terminal type match the original equipment, no rewiring or fitting changes are needed at installation.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-5899
• Product Type: Oil Pressure Sender
• Thread Size: 1/8 inch, 27 NPT
• Pressure Range: 80 PSI
• Terminal Type: 10-32 stud
• Fit Type: Universal Fit
• Material: Aluminum or Nickel
• Item Dimensions: 7 x 6 x 2 inches
• Weight: 0.29 pounds
• Current Rating: 1 Amps
• Mounting Type: Through Hole Mount
• Manufacturer: Teleflex Marine
• UPC: 030999563903

Fitment

• Crusader engines using the 700425 oil pressure sender
• Mercury Marine engines using the 34623 or 90806 oil pressure sender

Replaces (OEM)

• Crusader 700425
• Mercury Marine 34623
• Mercury Marine 90806

Frequently Asked Questions

What pressure range does the Sierra 18-5899 oil pressure sender cover? The Sierra 18-5899 is rated for an 80 PSI range, matching it to standard marine engine oil pressure gauges built for that range.

What thread size does this oil pressure sender use? It uses a 1/8 inch, 27 NPT thread, the standard thread for the engine block or oil gallery port it installs into.

Does the 18-5899 replace a Mercury Marine oil pressure sender? Yes, part number 18-5899 directly cross-references Mercury Marine 34623 and Mercury Marine 90806.

Is the Sierra 18-5899 a replacement for a Crusader sender? It is, this sender cross-references Crusader part number 700425.

What terminal type is used to wire the gauge to this sender? The 18-5899 has a 10-32 stud terminal for connecting the gauge wiring.

What is the 18-5899 sender made of? Construction is aluminum or nickel, chosen for corrosion resistance in the marine engine compartment.

How much does the 18-5899 oil pressure sender weigh? It weighs 0.29 pounds.

What are the dimensions of the Sierra 18-5899? The sender measures 7 x 6 x 2 inches.

Will this sender work with any 80 PSI oil pressure gauge? Yes, the 18-5899 is a universal fit sender intended for use with 80 PSI electric oil pressure gauges.

Is a mounting gasket or fitting included with the 18-5899? The product is the oil pressure sender itself; no separate gasket or fitting is specified as included.

What is the current rating of this sender? The Sierra 18-5899 has a current rating of 1 Amps.

How is the 18-5899 mounted? It uses a through hole mount, threading directly into the 1/8 inch NPT port on the engine.