AMT 3690-300-91 Viton Gasket and O-Ring Subgroup Kit
The AMT 3690-300-91 is the genuine Viton gasket and O-ring subgroup kit for AMT pumps — the complete set of static seals for the pump gathered into one part number. Static seals are the ones that do not move: the casing gasket, the cover O-rings, the plug and fitting seals. They are easy to overlook precisely because nothing about them rotates or wears in the obvious way.
The problem is that they age anyway. Every elastomer takes a compression set over time, hardens as plasticisers migrate out, and is slowly attacked by whatever the pump handles. A gasket that has been holding fine for three years will very often start to weep the moment the joint is disturbed and re-torqued for some unrelated repair — which is how a straightforward bearing job turns into a pump that leaks when you put it back together.
Every seal in this kit is Viton, the fluoroelastomer specified where solvents, fuels, oils, acids or sustained heat would swell and harden nitrile. If your pump handles anything beyond water and mild detergent, this is the right specification, and substituting cheaper nitrile rings is a false economy that shows up as a leak within weeks. Kit contents vary between models, so confirm the part number against the parts breakdown for your pump before ordering.
Key Features
- Genuine AMT (Gorman-Rupp) subgroup kit — all the static seals for the pump in one part number
- Viton (fluoroelastomer) throughout for solvents, fuels, oils, acids and higher temperatures
- Renews every gasket and O-ring at once, so no tired seal is left in the joint
- Avoids the leak that appears after a joint is disturbed and re-torqued
- Factory-matched parts — no cross-referencing individual numbers
Applications
- Full static seal renewal on an AMT pump
- Fitted alongside mechanical seal, impeller or bearing work
- Chemical transfer, solvent and fuel service
- Planned maintenance intervals and pump overhauls
- Marine, dockside, washdown and industrial pump service
Specifications
- Brand: AMT (Gorman-Rupp)
- Manufacturer Part Number: 3690-300-91
- Part Type: Gasket and O-ring subgroup kit
- Material: Viton (fluoroelastomer)
- Scope: Static seals for one pump
- Condition: New
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 this is the right kit and what it covers before you order.
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