Volume 2 Issue 3 - Lubrication

Article Index
Lube Notes: Amsoil Oil Bypass Filtration System
Filtration System Installation
Cost Comparison
All Pages

Amsoil Oil Bypass Filtration System

In summary, oil bypass filtration

  • Dramatically extends drain intervals;
  • Improves oil cooling;
  • Increases filtration capacity and life;
  • Increases fluid system capacity;
  • Efficiently removes small particles and soot;
  • Significantly extends engine life;
  • Allows equipment to run constantly on clean oil;
  • Increases engine efficiency; and,
  • Removes particles less than one micron in size.

Jon Moore and his Duramax diesel

Amsoil oil bypass filtration system components Dual remote filters for the Amsoil oil bypass filtration system Heath Diesel 6.5L diesel oil cooler

(Click any image to enlarge and for more information.)

Jon Moore of Boca Raton, Florida recently purchased a new Chevy Silverado pickup fully equipped with the Duramax and Allison for towing a fifth wheel trailer. Jon, a retired engineer from Pratt & Whitney Corporation and a longtime certified aircraft mechanic and pilot, read the Bypass article in maxxTORQUE, called me and purchased the Amsoil Dual Remote Bypass System. This article explains the installation procedure and provides some comments on the system components, ease of installation and system quality.


The Amsoil Bypass System comes as a complete kit for both the GM Duramax and the 6.5 Turbo Diesels. The Duramax kit that Jon needed is part number BMK-27. The BMK-27 is a dual remote oil bypass system that places the full flow filter and the bypass filter side by side on a manifold located remotely from the OEM filter location. Figure One, shows the components provided in the BMK-27 plus a custom made bracket that facilitates ease of installation. The original bracket for mounting the manifold, included in the BMK-27 kit, is simply not long enough to clear the stabilizer bar on the inside of the frame rail under the truck, so a custom made bracket was designed to allow clearance. As you can see from the photo, the materials are very high quality, bordering on overkill for this low pressure lube oil system.

Jon Moore and his Duramax diesel

Amsoil oil bypass filtration system components Dual remote filters for the Amsoil oil bypass filtration system Heath Diesel 6.5L diesel oil cooler

(Click any image to enlarge and for more information.)

Jon’s comments at the start summed things up:

I have been working on automobiles, airplanes, and various other vehicles/machinery for 45 years. I was very impressed with the design and quality of the components and hardware in the Remote Filter Kit. Over the years, I have dealt with a lot of retrofit kits, parts, etc., including aircraft hardware, that were inferior in design and quality to this kit. In addition, I found the instructions provided with the kit to be very clear and comprehensive: very user-friendly and easy to follow. In my judgment, anyone with a moderate mechanical ability could easily install this kit, including the assembly of the hoses.

As Jon said, the instructions come in the kit and, if you follow them, you will end up with a good installation. The following installation overview is not intended to replace those instructions but to give you an idea of what is involved.

Amsoil Oil Bypass Filtration System Installation

For this installation, as with any other, it is agood practice to read over the instructions and absorb the information prior to organizing your approach to the installation. The location of the remote filter mount assembly is the first issue you have to solve – where are you going to put the filtration unit? For GM heavy duty pickups, a very good, if not the best, location is under the truck on the inside of the frame-rail. The filter unit fits nicely there and sits behind the frame, hidden from view when looking at the truck. This is where the special custom made bracket comes in handy, (Figure Two). The extra throw/length of the bracket allows for extension past the stabilizer bar. This bracket is available from www.thelubepage.com. When you have completed drilling holes for installing the bracket, place the bracket aside for later installation. Now is a good time to install the filter adapter assembly for oil supply and return. Figure Three shows the filter adapter installed and ready for the supply and return hoses to be connected. You will need to install the fittings into the adapter and then install the adapter in place of the OEM oil filter. Be sure to orient the threaded nipple on the side in order to facilitate easy installation of the hose assembly.

Amsoil Oil Bypass Filtration Installation Figure 2

Amsoil Oil Bypass Filtration Installation Figure 3 Amsoil Oil Bypass Filtration Installation Figure 5 Amsoil Oil Bypass Filtration Installation Figure 5 Amsoil Oil Bypass Filtration Installation Figure 6 Amsoil Oil Bypass Filtration Installation Figure 7 Amsoil Oil Bypass Filtration Installation Figure 8

(Click any image to enlarge and for more information.)

Next, install the threaded nipples in the filter mount assembly and attach the filter mount to the custom made bracket (Figure Four). It is easier (but not mandatory) to attach the filter mount to the bracket and then attach the completed assembly of the bracket and filter mount to the frame-rail.

With the filter mount in place, measuring and assembling hoses for oil supply and return is the next task. The hose assembly is critical and following the step-by-step instructions to the letter is the best way to insure a correctly assembled hose. When determining hose length, include a designed bend in the hose, as in Figure Five. This bend will prevent flow noise from resonating and annoying you while you drive. Figure Six shows the hose fitting in the vise and the threaded nipple being screwed in; using a vise is a real plus for this procedure. Install the hoses between the filter mount assembly and the filter adapter assembly: snug but not over tight.


You are now ready to install the full-flow and oil bypass filters to the filter mount (Figure Seven). Depending on what tools you have, it is usually easier to install the bypass first. Fill the bypass filter with oil and lube the o-ring with a light film of oil. Spin the bypass filter on to make engagement and then turn an additional three-quarters to one turn. You may need to use a strap wrench to complete the additional turn (the size of the bypass filter makes it hard to find a filter wrench large enough to fit over the bypass filter). The full-flow filter (Amsoil EAO-26) is installed exactly the same but you can use a standard filter wrench to achieve the final turn for proper gasket compression.

With the assembly and installation complete (Figure Eight), the real test is starting the engine and pressurizing all parts of the Amsoil bypass system and checking for leaks. Let the engine come to full temperature and run the engine for at least 30 minutes to insure the bypass system is up to operating temperature. If a leak is going to occur, it will be when all parts are hot and clearances are expanded. Carefully inspect the filters: if any oil seepage occurs tighten the filter (when hot) an additional one quarter turn and then back off an eighth of a turn. While this insures good compression of the o-ring, backing off an eighth of a turn insures that the o-ring is not stretched or deformed.

Oil Bypass Filtration Maintenance

The oil bypass filtration system requires filter changes based on vehicle use as follows:

When used in conjunction with Amsoil motor oil and an Amsoil EaO or Donaldson Endurance™ filter, the EaBP should be changed every other full-flow filter change up to 60,000 miles. When used with other brands of motor oil or full-flow filters, the EaBP Filter should be changed every other full-flow filter change. Amsoil recommends using oil analysis when extending oil drain intervals.

Looking Ahead

Jon intends to monitor the performance of the Amsoil bypass system with oil analysis and we will post those results in Lube Notes in future issues so that we can track just how much of a difference the system will make.

From the pictures, we can see that Jon completed the installation of the oil bypass system in a very professional manner: it looks great. I have installed several of the oil bypass kits from Amsoil and I agree with Jon that anyone with a moderate mechanical ability will be able to easily install this kit.

Amsoil Bypass Filtration Cost Comparison

Will the bypass filtration system be cost effective to use? Let’s look at the numbers for 30,000 miles:


Standard oil change with Amsoil 15W-40 CJ-4 heavy duty diesel engine oil (part # DME) at 15,000 miles

10 quarts DME retails for $8.55 per quart = $85.55

1 Amsoil EAO-52 full flow filter = 18.85

Total, One Oil Change = 104.40

Total, Two 15,000-mile oil changes = 208.40

Bypass oil change with Amsoil 15W-40 CJ-4 heavy duty engine oil (part # DME) at **30,000 miles

12 quarts DME retails for $8.55 per quart = $102.60

*2 EAO-26 Amsoil full flow filters = 46.40

1 EaBP-100 bypass filter = 40.25

Total: = 189.25


Two 15,000-mile oil changes at $104.40 each = $208.40

Bypass Total: = $189.25

Savings with Bypass System per 30,000 miles: = 19.15

*EAO-26 full flow filters are used on the dual remote bypass system

** Oil drain intervals can be extended with used oil analysis


Obviously, the purpose of this comparison is not to hype the savings but to demonstrate that you can use a bypass system and gain all the benefits for no additional costs and, in fact, save some on the overall cost. Most users of the Amsoil bypass systems extend oil drain intervals using oil analysis to at least 60,000 miles, achieving a significant savings on oil change cost with no loss in oil quality. The kit price from www.thelubepage.com, including the custom bracket, is $375; both the kit ($360) and the bracket ($25) are available separately.

Do you need a bypass filtration system? As I explained, in the Winter 2009 issue of maxxTORQUE, the LMM engines, with the new pollution control systems, are well served by bypass filtration. In fact, all diesel engines will benefit from a good bypass filtration system, but the LMM really needs it.

In the next issue of maxxTORQUE, I will explain oil analysis and post some reports from Jon’s Duramax. By first looking at the ins and outs of oil analysis and then reviewing Jon’s specific oil analysis, we should be able to make sense of what he sends us. I am looking forward to seeing the oil analysis and to sharing this beneficial information with you.

As always, for questions or comments on Lube Notes, contact me or submit questions at www.thelubepage.com

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