Waekon/Hickok 46568 OBDII EVAP Leak Master Test Kit


Staff member
BAT Auto Product Review:

46568 OBDII
EVAP Leak Master Test Kit

Product review performed by:
Bruce Bonebrake
Managing Editor at BATauto.com

The test kit comes in a nice plastic carrying case. Compartments for all of the included accessories are designed to hold everything securely in place and at a glance, you will be able see if everything is back in place and not left behind.

The kit comes with "user friendly" manuals that make understanding the system and using the tester's a snap. I have tried to limit the amount of images, but, there are several, so please pardon the article load time. I didn't want to just write about how the system works but instead actually show you the setup and the tester's in operation. I think after you read this review you will find, as I did, this system is a "must have" if you plan on performing any OBDII EVAP repairs. Also included with the user manuals, is the tester warranty card and a unique Pressure Guideline Chart. We'll explain what this is later on during our testing.

How many times have you had a vehicle pull up to your shop, MIL on, and you install a scanner to find a DTC set due to a malfunction within the EVAP system? We have all been there, and there have been the rare times that the repair was as simple as tightening a loose fuel cap. Then there were the vehicles that the fuel cap wasn't the problem. Now what? Without some means of testing the system for leaks and for the proper flow, there is no way we can accurately pinpoint the cause of the problem. Even when you tightened the customers fuel cap, how can you be 100% certain that the cap was the problem, in other words verify the repair? Let's face it, there is no way you can, and you may wind up seeing the customers car over and over again for the same complaint. Having a comeback is one thing that none of us can afford. We are professionals and our reputation is jeopardized anytime a customer has to return to our shop with the same problem we were supposed to correct the first time. On the OBDII EVAP problems, I think we finally have an answer.

Corporate Headquarters
10514 Dupont Ave.
Cleveland OH

Toll Free Product Info and Technical Support
WAEKON A Division of HICKOK, Inc

The EVAP system is not a new system used on OBDII vehicles. As a matter of fact, it is part of the first emission systems added to passenger vehicles. The EVAP system's task is simple. Store the vapor created in the vehicles fuel tank, and allow it to be burned in the combustion process when commanded to do so. Why? Again simple..fuel in the fuel tank, the vapors from the fuel is a form of vehicle emissions. We all think of emissions as being what is being expelled from the tailpipe of a vehicle, after all that is what the emission test stations test for when the vehicle is brought in for an emission test. The probe is inserted in the tailpipe or the vehicle is placed on a Dyno, and the emissions expelled from the exhaust are collected/measured and the vehicle will pass or fail depending on the emission level specification of the specific vehicle. Most emission tests will also include a fuel cap test. The fuel cap that has been used for many years, since the introduction of the EVAP system, is a "non-vented" type fuel cap. The fuel cap will be tested and either pass or fail. The difference on the OBDII EVAP system, is that the system, like many other added systems used on OBDII vehicles, is being carefully monitored by the vehicles OBDII on-board computer. The EVAP system is monitored for a leak within the system, and also whether or not the system correctly flowed the fuel vapor when the EVAP system is commanded to flow. Being a controlled and monitored system by the OBDII on-board computer, if a failure should result, the MIL will illuminate to alert the driver that there is a problem. An OBDII scanner is used to retrieve the DTC(s) that are present, or history, in memory. So there you have it. As you already may know, this is a simple, yet a hard system to properly diagnosis. With the engine and fuel tank usually located far apart from one another, the tubing, hoses, EVAP canister, control devices and the wiring make the EVAP system almost as large as the vehicle. Where to start, how determine a fault, and how to verify the repair, is made simple with the Waekon 46568 OBDII EVAP Leak Master Test Kit. Let's get started..

The Waekon 46568 OBDII EVAP Leak Master Test Kit contains two testers. Let's start with the OBDII Fuel Cap Tester.

The Fuel Cap Tester comes complete with four fuel cap adapters.
After identifing which adapter will be used on our test vehicle, the cap simply is screwed onto the adapter.
Attach the cap to the correct adapter and lock in place exactly as it would be on the fuel filler neck of the vehicle.
To prepare the new tester for use, remove the paper slip that is in place to insure that the tester battery will be fresh on arrival.
Next, we attach the fuel cap adapter to the tester. The cap adapter is attached to the "quick disconnect" fitting on the tester.
To start the fuel cap test, the "Press To Start" button on the tester is pressed.
The fuel cap tester is "pumped up" by using the trigger operated hand pump built into the tester. The tester is pumped up noting the LED's on the tester. When the yellow LED illuminates, the pumping is stopped. Next, simply watch the LED's on the tester....


Staff member
As you can see by the illuminated green (PASS) LED on the tester, our test vehicle fuel cap is good. If the cap would be defective, either the LED located in the red color zone of the tester (OBDII Fail) or the LED in the yellow zone of the tester (I/M fail) would have illuminated. This is a VERY nice, accurate, and easy to use tester!!

The test vehicle is a 1997 Pontiac Grand Prix with a 3.8L VIN M SFI engine. The vehicles MIL light (Service Engine Soon) is illuminated, and the DTC PO441 is the history code that caused the MIL light to illuminate. As you can see by the DTC description, the code PO441 tells us that the EVAP System No Flow During Purge.

By locating and inspecting the vehicles underhood decal, on this vehicle there is not an EVAP Service Port for the EVAP system. Not all OBDII vehicles will be equipped with an EVAP Service Port. Also, the decal shows that the routing is fairly simple for the EVAP system. The inlet hose on the EVAP SWITCH is the hose/nylon line that is routed from the EVAP Canister located at the rear of the vehicle. The "no flow" that caused the DTC to set could be caused by several things, one being a leak within the EVAP system. Now to determine where and if there is a leak in the EVAP system.



Staff member
Before we go on with the testing on our test vehicle, I want to stop here for a moment and talk about the EVAP Service Port. Our test vehicle does NOT have an EVAP Service Port. You most likely have seen this port with the green cap. The vehicle I have taken the pictures of here is a 1998 Jeep Cherokee 4.0L. As you can see by the decal above, the EVAP system is slightly different than our test vehicle. One thing to remember before performing any testing, is to properly identify the system you are working on including the vehicle's various system components. Also, note the label on the EVAP test port. Ok, let's get back to our test vehicle..

The second tester included with our kit is the EVAP System Leak Tester. The main component of the tester is the Pressure Manifold Unit (PMU) which is shown above. The PMU is a portable, self-contained handheld unit designed to check the vehicle's EVAP system's ability to hold pressure.

In order to use the PMU, we need to prepare it for use. The PMU comes with a shipping plug installed in the inlet port. First we need to remove the plug.

The inlet of the PMU should have a filter in place, make sure that it is in there. The filter will stop any debris from entering into the unit. Spare filters are included with the kit.

The manufacture recommends using bottled Nitrogen equipped with a regulator as the pressure source for the PMU.. An alternative source for suppling the pressure needed for the PMU, is to use shop air or a portable compressed air tank.


For the review I am using shop air from my air compressor. I mainly wanted to show you how I would recommend setting up the PMU using this as the source of pressure. I would strongly suggest that you purchase a "pre-filter" for the PMU. REMEMBER the manufacture recommends using nitrogen and that is ultimately what the PMU is designed for. Nitrogen is a clean pressure source for the PMU unlike shop air. MAKE SURE that you leave the PMU inlet filter in place!! The pre-filter is NOT installed to eliminate the filter that the PMU is equipped with, but instead to help trap contaminates before they enter into the PMU inlet filter. Keep in mind this is a high quality precision unit. The service you will receive from it depends on how you care for and maintain it. The steps in the preparation of the PMU above are fairly self explanatory. Make sure that the pre-filter you purchase is designed for air and is rated for the supply PSI the system will be using. The picture on the lower right shows my air compressor gauges and you can see where I have the regulator set at 120 PSI. The manufacture specifies in the instruction booklet that the source pressure MUST NOT exceed 175PSI. If you use Nitrogen as the pressure source you will need to have a pressure regulator in place to lower the pressure to 175PSI. I have found while reviewing the tester that 120PSI works very well using my shop air. The pre-filter that I installed is rated at 150PSI so I am well below that rating and I still have enough pressure/volume supplied to the PMU that the tests have worked perfectly. This may vary depending on your compressor or if you use a portable air tank. Just remember not to exceed the pre-filter limit or go over 175PSI. Also, the air hose from the source to the PMU, it is recommended to use a flexible supply hose , preferably polyurethane. If you are unsure of your hose compound or if your air hose is in poor condition, do yourself a favor and purchase a new polyurethane air hose to use with the PMU. The hose is fairly inexpensive and readily available from your part supplier.


Staff member

We have identified the EVAP system on our test vehicle, and the vehicle is not equipped with the EVAP Service Port. The tester includes a Universal Filler Neck Adapter (above left). The filler neck adapter comes assembled and ready to install. To install the filler neck adapter, remove the fuel cap, next inspect the filler neck. As you can see, our filler neck is in pretty rough shape. The sealing surface for the fuel cap is rusty and the anti-splash shield is bent and is pushed back into the filler neck. This is a potential problem right here. I want to know for certain if this is the cause of the failure, so I am going to leave it alone for now and proceed with the test.

Installing the universal filler neck adapter is very simple. With the fuel cap removed, the "J" hook on the end of the neck adapter rod is inserted into the filler neck through the splash shield opening, and will latch onto the inner edge of the filler neck. Once the J hook is in place, and the adapter rod centered in the filler neck, firmly pull the T-handle towards you. While you are pulling the T-handle, slide the filler neck seal adapter down the rod until it is firmly seated on the filler neck. Next, to lock the filler neck seal into place, push the slide and spring assembly towards the adapter until the spring is fully depressed. You need to pay attention to where the slide release lever is positioned. You want to make sure the release lever is positioned away from the tester's fitting. A correctly installed universal filler neck adapter will look like the picture on the top right. Now we have an EVAP Service Port!


Staff member

With the universal filler neck adapter in place, next we are ready to attach the PMU to the adapter and the pressure source to the PMU, which in our case, is the shop air.

VERY IMPORTANT!!!! Before we go any further, we need to ground the body of the PMU to the test vehicle. This can be easily achieved by attaching a jumper wire to the green ground screw on the PMU and attach the other end of the jumper wire to the metal body of the car. Our test vehicle is a metal bodied vehicle, so one of the screws used to attach the filler neck mount to the vehicle would be a great attachment point.
Now, let's talk about why this is so very important. It is common for vehicles to build up electrostatic discharge (ESD). Not only can ESD damage electronic equipment, but it can also ignite fuel vapors which can cause a fire and explosion. Also keep in mind where we are working here. We will be working at the fuel filler neck, EVAP cansiter and fuel tank area. Take extreme caution when working around fuel or the vapors from the fuel!!!

We need to seal the EVAP system before we can accurately test for a leak. This procedure will vary from application to application. Normally an evaporative system is designed to vent the canister to the atmosphere, and because the PMU works by monitoring the pressure introduced to the evaporative system, the system must be sealed before testing. On this vehicle, I want to locate the EVAP line from the canister to the vacuum switch. The EVAP system components under the hood are all located under the engine sight cover. Removing the sight cover is simple as shown above. Once off, the EVAP line located, a plug is installed in the hose. Now, back to the rear of the vehicle.

We have the system sealed at the engine, next we need to isolate the EVAP canister. The EVAP canister used on our test vehicle is located inside the left rear quarter panel. By doing a visual inspection of the EVAP canister I am not going to touch the hoses, not yet anyway. The PURGE hose nipple looks like it has a crack on the bottom side of it.



Staff member
Before we start, the fuel tank must be at least 1/2 tank (50%). Included with the literature, is the Pressure Guideline Chart. The chart lists the various fuel tank capacities, ranging from 10 Gal to 29 Gal. The level of fuel in the tank is listed (in %) from 50 to 100, and with that information you will be able to determine by the chart, the number of seconds the pressure gauge will be monitored.

To pressurize the EVAP system, you press and release the brass button on the PMU.

We want to pressurize the EVAP system to 14"-15" H2O. As you can tell by reading the gauge, I can not pressurize the system

As soon as the button is released, immediately the gauge falls to 0

The PMU is equipped with a yellow locking lever that can be used to lock the button down (increase pressure) which is very handy so you can idenify where the source of the leak is at.

Just as I suspected.. I can hear and feel the air escaping around the vacuum fitting of the canister. We have a defective EVAP canister. Also, although with the massive leak from the cracked fitting on the canister, it is hard to determine, if you remember, we have some problems to address with the fuel filler neck. Now that I know what I need to do, its time to get this vehicle repaired.

The defective EVAP canister removed and compared to the new replacement.

The replacement EVAP canister does not come with the mounting bracket.

With a little work, and spray paint, the original bracket is ready for reuse.

The bracket installed onto the new EVAP canister and is going back into place.

The bracket is reattached to the inner body of the quarter panel.

The EVAP canister hoses were also replaced and clamps installed to make certain we have a good leak free connection.

Reattach the muffler hangers. I found that if the muffler hangers were removed, the EVAP canister can easily be removed from the vehicle.

The fuel filler neck cleaned up nicely. The rust on the sealing edge was just surface rust so we were able to clean it up and save it. Also, the anti-splash shield was easily bent back into position

With the repairs made, the Universal Filler Neck adapter and the PMU reattached, the EVAP system immediately pumped up to the 14.5" H20 as shown in the picture above. Excellent!!

Next, following the Pressure Guideline Chart, the vehicle has an 18 Gal fuel tank. The fuel level is 75% so by using the chart, the gauge would be monitored for 85 seconds. What we are looking for is any drop in pressure, to pass, the drop must be less than 6" H2O. We PASSED!!

Before we remove the PMU, we need to perform one more test. While the system is still under pressure, we want to unseal the system.

We sealed the system by plugging the EVAP line that attached to the Vacuum Switch. With the plug now removed...next...

back at the PMU, the gauge should drop to O, and it did. Well, I think it is time to get the vehicle all buttoned back up and go for a test drive!!

We started out with a problem with the EVAP system on the test vehicle, a 1997 Pontiac Grand Prix, and step-by-step using the procedures listed in the manuals and with the testers included in the Model 46568 OBDII EVAP Leak Master Test Kit, we pinpointed the problem area, performed the repair, and even verified the repair!! Without a test kit such as this, I honestly don't know how we could have achieved that. Being able to see a problem, as I did with the fuel filler neck and the EVAP canister, we can "guess" that these were the problem(s) that caused the MIL to illuminate, but how would we know for certain? And lastly, how would we be able to verify the repair? We always rate the product we perform a review on, and that will be extremely easy with this product, it is just fantastic!! The ease in operation, well explained manuals, the quality of the testers and adapters is truly amazing!! It was easy for me to see that the company's main concern was quality. So many times we purchase equipment and not long after we have it and use it, we discover that the company that designed and manufactured the product, did not intend for it to last. I can honestly see this product surviving for many years and perform problem free. The attention to every detail tells me that. Very well done!!!

Product review by,
Bruce Bonebrake www.batauto.com
Great review! I found this very helpful, I recently won this evap tester from eBay and it doesn't have the manuals with it. I tried to order a copy from waekon and hickok, but they no longer provide support for this kit. Do you have any idea where I might be able to find a copy of manuals? Any help would be greatly appreciated. Thanks John Walker Russells Reliable Repair