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BMK-11 By-Pass System Installation

BMK-11 By-Pass System installed on an imported 1991 Toyota Land Cruiser (HDJ81) 4.2L Turbo Diesel. Pictures provided by JDM Cars Canada

*** Note: BMK-11 has been replaced with new & improved BMK-21 ***

BMK11 Kit


By-Pass Oil Filter Description

The Ea By-Pass Oil Filter (EaBP) provides the best possible filtration protection against wear and oil degradation. Working in conjunction with the engine’s full-flow oil filter, the AMSOIL Ea By-Pass Filter operates by filtering oil on a “partial-flow” basis. It draws approximately 10 percent of the oil pump’s capacity at any one time and traps the extremely small, wear-causing contaminants that full-flow filters can’t remove. The AMSOIL Ea Bypass Filter typically filters all the oil in the system several times an hour, so the engine continuously receives analytically clean oil.

By-pass Basics

By-pass oil filtration features a secondary filter with the purpose of eliminating nearly all contaminants in engine oil. They have high capacities and eliminate much smaller particles than full-flow filters, including soot. By-pass filters reduce engine wear and increase oil volume, but their high efficiencies mean they also have higher restriction and must be used in conjunction with a full-flow filter. By-pass filters operate by filtering oil on a “partial-flow” basis. They draw approximately 10 percent of the oil pump’s capacity at any one time and trap the extremely small, wear causing contaminants that full-flow filters can’t remove. Bypass
filters have a high pressure differential, causing the oil to flow through them very slowly and allowing for the removal of smaller contaminants. It is called by-pass filtration because the oil flows from the by-pass filter back to the sump and bypasses the engine. This continual process will eventually make all of the oil analytically clean, reduces long-term wear and can extend drain intervals.


BMK11 installed on 1HD-T

1. To install the By-Pass kit without drilling holes in the body.

2. Easy access to replace filter.

3. Use the biggest available filter to maximize oil system capacity and oil cooling.

Step by Step Installation Procedure

BMK11 Diagram
Click here to download the BMK-11 installation and servicing instructions

The BMK 11 system can easily adopted to almost any vehicle. The high pressure oil is tapped out of Oil Pressure Sending Unit using a "T" adaptor. Refer to the PDF file for "T" adaptor part numbers for all makes and model.

Step 1:

Remove Oil Pressure Sending Unit from engine block and install the "T" adaptor with its extension.

sending unit removed

Remove sending unit and install the T adaptor

With the full flow filter out of the way you can see the installed "T" clearly.

Step 2:

high pressure line outMeasure and cut braided hose that come with the kit. Connect hose fittings to the ends.

Install one end of the hose to the "T". Other end of this hose will connect to the Filter Mount Assembly "IN".

Step 3:

install sending unitInstall the sending unit to the "T" and connect the oil pressure wiring harness to restore oil pressure gauge reading.

Step 4:

Installing the filter mount assembly with an oil sampling petcock valve (optional). Picture shown with by-pass mount & by-pass filter.

filter adaptor mount Fabricate a bracket to install the Filter Mount Assembly. The filter can be installed in an angle. Acceptable mounting angles are between 20° - 160°. Refer the PDF file for the diagram. Install the Filter Mount Assembly to the fabricated mounting bracket as shown in the picture. Connect the high pressure oil line from the "T" to the "IN" of the Filter Mount Assembly with 90° elbow connector.

Step 5:

Install 90° elbow connector to the Filter Mount Assembly "OUT" for the return line.

Step 6:

The return oil line can be sent to the sump or the oil filler cap using the "Return Line Swivel Fitting". This set up is easier than drilling into the oil sump. The part number is BP-89

return line swivel adaptor

return line to oil cap

Mount the "Return Line Swivel Fitting" to the oil filler cap and connect one end of the return line braided hose.

Step 7:

oil line insulationConnect the other end of the return line to the Filter Mount Assembly "OUT". Take precaution and insulate the braided hose where it comes in contact with metal parts subject to vibration and heat. This will ensure a long lasting lines.

Step 8:

install filter elementFill filter element with oil, and install it to the filter mount assembly. Start engine and check for leaks.

Step 9:

check oil flowCheck for oil return from the by-pass kit. This might take up to a minute. The delay is due to the large filter filling up with oil. Once you see the oil coming out of the return line, turn off engine and check for oil level. This set up will take about 3 quarts of additional oil. Add oil as required and again check for leaks.

Installation is complete and this engine is now protected beyond normal standards. Now the filtration efficiency is about 98.7 % @ 2 microns. This is almost like replacing motor oil every 10 minutes!

By-Pass Filtration Benefits

Soot Removal:

Soot Removal ChartAMSOIL's high-efficiency by-pass filter element is also a soot removal device. AMSOIL Ea By-Pass Filters use a synthetic/cellulose sandwiched media. The inner layer of the element is composed of a highly efficient cellulose media covered with a full synthetic media outer layer. These filters remove 39 percent of soot contaminants less than one micron. Soot removal efficiency increases approximately 10 to 14 percent when the EaBP Filter is used in conjunction with a standard full-flow filter.


• Dramatically Extended Drain Intervals
• Improved Oil Cooling
• Increased Filtration Capacity and Life
• Increased Fluid System Capacity
• Efficient Small Particle and Soot Removal
• Significantly Extended Engine Life
• Equipment Constantly Runs on Clean Oil
• Increased Engine Efficiency
• Remove Particles Less Than One Micron

Rating & Review Section

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Blog Title: AMSOIL By-Pass Filtration System on 1HDT Turbo Diesel Engine HDJ81
Current Rating: 4.88 out of 5 stars
Votes & Reviews: 8 vote(s) and 4 user reviews.

Reviewed by Jr : space

1HD-FTE in LC100

Do you have any fitment options for the LC100/1HD-FTE?

Item Reviewed: AMSOIL By-Pass Filtration System on 1HDT Turbo Diesel Engine HDJ81
Discussion Url | Seattle, Washington

Re: 1HD-FTE in LC100

This setup will also work for 1HD-FTE Replied by Tech Admin

Reviewed by Graeme: space

Toyota 1HDT bypass oil filter kit

Can I have this kit sent to Australia

Item Reviewed: AMSOIL By-Pass Filtration System on 1HDT Turbo Diesel Engine HDJ81
Discussion Url | Perth, Western Australia

Re: Toyota 1HDT bypass oil filter kit

No, but we have dealers in Australia who should be able to order it for you. Search for AMSOIL in Australia to locate the dealer. Replied by Tech Admin

Reviewed by JOE: space




Item Reviewed: AMSOIL By-Pass Filtration System on 1HDT Turbo Diesel Engine HDJ81
Discussion Url | Parramatta, New South Wales

Reviewed by Joe: space


How available are ur filters in aus and is there a ryco replacement if I can’t get ur one in time

Item Reviewed: AMSOIL By-Pass Filtration System on 1HDT Turbo Diesel Engine HDJ81
Discussion Url | Frankston East, Victoria

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