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AMSOIL Bypass Oil Systems
Maximum filtration performance for virtually all heavy-duty diesel and gasoline applications, including Class 6, 7 and 8 heavy-duty trucks, off-road equipment, buses, generators, marine engines, logging, and agricultural equipment.
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BMK30 is the AMSOIL Heavy-Duty Bypass System, designed specifically for the AMSOIL Heavy-Duty Bypass Filter (EABP120). It is built for Class 8 trucks, off-road heavy equipment, buses, generators, marine engines, logging and agricultural machinery, and any application with a sump capacity from 24 to 60 quarts. The mount is cast aluminum with a steel filter stud and a marine powder-coated finish, so it tolerates road salt, debris, and engine compartment chemistry through a long service life. Multiple BMK30 systems can be plumbed in series for very large sumps.
The AMSOIL bypass system is the single-remote bypass system, mounting one EaBP element on a remote bracket. It works in parallel with the engine's full-flow oil filter to remove soot and particles down to two microns and larger, contaminants the standard full-flow filter cannot reach. Adding the system increases the total fluid capacity by approximately 1 gallon (depending on hose length), depending on the length of the installed hose and the distance between the engine and the mount.
The fitting required to pull pressurized oil from the engine and the return fitting that drops oil back to the sump are typically included for vehicle-specific kits. For the universal kits (BMK21 and BMK23) and for non-cataloged engine families, the source and return fittings should be selected based on the actual port sizes on the engine; AMSOIL Technical Services can recommend the correct sizes.
An AMSOIL bypass filter operates on a partial-flow basis, drawing less than ten percent of the engine's oil-pump output at any moment and routing it through a high-density filter element. Because the bypass element handles a small share of the flow, the media can be much denser than a full-flow filter, capturing soot, sludge, and small wear particles a full-flow filter passes. The cleaned oil returns to the sump, and over the course of an hour the bypass loop typically polishes all of the oil in the system several times.
The result is a continuously cleaner oil sump, slower additive consumption, slower viscosity rise, and reduced rates of bearing, ring, and turbocharger wear. When paired with AMSOIL synthetic motor oil and used-oil analysis, the system supports extended drain intervals well past the OEM-recommended schedule on most heavy-duty diesel and light-duty turbo-diesel pickup applications.
The mount is built from cast aluminum with a steel filter stud and finished in a marine powder-coated paint that resists road salt, debris, and engine compartment chemistry. The included fittings, hose, and clamps are sized for the operating pressure and temperature of typical light-duty and heavy-duty diesel and gasoline applications. Detailed installation instructions cover plumbing decisions, mounting locations, and a step-by-step process to bleed the system after the first start.
Confirm fit by year, make, model, and engine in the AMSOIL Vehicle Lookup Guide before ordering. The matching synthetic motor oil and full-flow filter program is summarized in the AMSOIL diesel oil guide and the oil filter guide.
The AMSOIL Bypass Filter element should be replaced at the limits published for its size, whichever comes first.
| Element | Mileage | Hours | Time |
|---|---|---|---|
| EABP90 | 60,000 mi (96,500 km) | 600 hr | 2 years |
| EABP100 | 70,000 mi (112,600 km) | 800 hr | 2 years |
| EABP110 | 80,000 mi (128,700 km) | 1,200 hr | 2 years |
| EABP120 | 120,000 mi (193,100 km) | 1,800 hr | 1 year |
Bypass element life depends on duty cycle. Used-oil analysis is the recommended way to confirm the interval is appropriate for the engine, the operating environment, and the AMSOIL synthetic motor oil in service.
The BMK30 is sold as a complete kit with the mount, hose, fittings, hardware, instructions, and bypass element listed above. AMSOIL Bypass Systems are backed by the AMSOIL Limited Liability Warranty. Confirm the right system for the engine in the AMSOIL Vehicle Lookup Guide and review the matching filter program in the oil filter guide, then order the AMSOIL Heavy-Duty Bypass System.
Very good products from Amsoil Extremely recommended
Would recommend this to a friend.
I use these filters in conjunction with my regular Amsoil filters in my diesel and immortal’s 2014 Subaru XV Crosstrek. Strongly recommend all these filters for extended oil change intervals.
Would recommend this to a friend.
My local dealership recently had to replace the upper oil pan gasket. When I went to pick up my vehicle, the mechanic asked what type of oil I used. He was extremely impressed by the internal cleanliness of my engine at 120,000 miles.
Would recommend this to a friend.
No. Installing an AMSOIL Bypass System does not void a new vehicle warranty when the system is installed correctly and does not modify the engine itself. The Magnuson-Moss Warranty Act prevents an OEM from voiding the warranty solely for adding a bypass loop to the existing lubrication system, and AMSOIL bypass parts are backed separately by the AMSOIL Limited Liability Warranty.
No. The bypass element works in parallel with the engine's standard full-flow oil filter, not in place of it. The full-flow filter still handles the immediate moment-to-moment lubrication load, while the bypass element polishes the same oil over the course of operation.
This system is sized for the EABP120 bypass element. The element ships with the kit and is also stocked as a service-replacement part for future filter changes.
Adding the BMK30 system increases total fluid capacity by approximately 1 gallon (depending on hose length). The actual amount depends on the length of installed hose and the distance from the engine to the mount. Top off after installation, then verify the level with the engine dipstick after a full warm-up cycle.
Yes. The kit includes detailed installation instructions, and most installations can be completed by a competent home mechanic with standard hand tools and basic plumbing. Common installer decisions include the source-port location for pressurized oil and the return-port location near the oil pan; AMSOIL Technical Services can recommend specific port locations on engines without a published kit.
Yes. AMSOIL recommends pairing extended drain intervals with periodic used-oil analysis. The oil analysis report confirms wear-metal levels, fuel and water contamination, oxidation, and remaining additive life so the actual drain interval can be set based on data rather than a fixed schedule.