Yamada 771712 Valve Body Gasket for NDP-40 to NDP-80
The Yamada 771712 is a factory valve body gasket used in NDP-40, NDP-50 and NDP-80 Series pumps. It is cut to the exact port pattern of the joint it seals, which is why a generic sheet gasket is not a substitute - the holes have to line up with the air passages.
A tired gasket lets air cross between passages that should be isolated, and the symptom is a pump that runs erratically, stalls at the end of a stroke, or exhausts continuously without cycling. Because the leak is internal there is nothing to see from outside, which is why a gasket is one of the first things to replace when an air motor misbehaves.
Key Features
- Genuine Yamada replacement valve body gasket
- Fits NDP-40, NDP-50 and NDP-80 Series pumps
- One per pump
- Cut to the factory port pattern so air passages line up
- Restores a positive seal between machined faces
- Inexpensive part that prevents erratic running and stalling
Applications
- NDP-40, NDP-50 and NDP-80 Series pumps
- Air valve and pilot valve overhauls
- Chasing erratic cycling or a pump that stalls
- Reassembly after any joint in the air motor is opened
- Scheduled air motor service
- Marine, industrial and transfer duty
Specifications
- Brand: Yamada
- Manufacturer: Yamada America
- Manufacturer Part Number: 771712
- Part Type: Valve Body Gasket
- Fits: NDP-40, NDP-50 and NDP-80 Series pumps
- Quantity Used: One per pump
- Series Port Size: 2 in on the NDP-50 Series
- Condition: New
Frequently Asked Questions
Q: The pump runs erratically or stalls. Could a gasket be the cause?
Yes, and it is a common one. A blown gasket lets air cross between passages, so the valve never gets a clean signal to shift and the pump hesitates, stalls or exhausts continuously.
Q: Does it matter which way round the gasket goes?
Yes. The holes match the port pattern of that joint and are often not symmetrical. Fitting one reversed blocks a passage and the pump will not cycle.
Q: Should I use sealant as well?
No. The joint is designed to seal on the gasket alone, and sealant squeezed into an air passage is a good way to create a fault that is very hard to find.
Q: How should the faces be prepared?
Clean both back to bare metal with a plastic scraper, then check for scoring across the joint. Do not use an abrasive disc, which dishes the face and creates the leak you are trying to cure.
Not sure this is the right part? Send us a Picture of the Pump Plate on your pump and the CLR Marine team will confirm the correct valve body gasket.
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