Attention: TDR Forum Junkies 
“PRIME-LOC” MANUFACTURER RESPONSE – Ashland Technologies, Inc.
As always, Ashland Technologies prides itself in providing a premium product that is supported by superior customer service. We have always stood by our products in the past and will continue to do so well into the future. We do empathize with each of you that may be concerned about this situation, and assure you that we are working to determine the root cause and develop a solution.
At this time, our aggressive co-operative research efforts reveal that “Prime-Loc” is NOT THE CAUSE OF INJECTION PUMP FAILURE. We are in agreement with other industry leaders that poor performing lift pumps are the apparent root cause of injection pump failures. With this in mind, we feel this concern is limited to 1998 and 1999 ISB engines. So at this time, all other vehicles should not be at all concerned. Further testing is being conducted, and we will provide status of those results.
Since the first of only three customer service calls received, our team has been diligently researching the problem. We have consulted with Chuck Arnold (The Power Shop), Steve St. Laurent and several others to gather our findings in order to co-develop a solution, and we thank each of you for your input and support. We have also conducted extensive testing ourselves, and will continue to do so until a solution is reached.
Our initial research and testing has revealed the following facts:
1. Lift pump and injection pump failures have been an ongoing problem in several ISB application stemming from School Bus, Motor Home, and yes – Your Dodge Ram Diesel! Details of these concerns can be found in TDR Issue 30, page 52 and 53.
Conversations with Mr. Arnold (Power Shop) reveal that they have seen three failures at their shop, and only one of them was equipped with a Prime-Loc system. The other two vehicles were not equipped with “Prime-Loc” and still experienced a failure. They have a case of a vehicle (not equipped with Prime-Loc) that experienced multiple failures within a thousand miles of travel under heavy load.
In researching other Cummins shops, we have been made aware of a high rate of lift pump and injection pump failures on NON-“Prime-Loc” equipped units. All of these vehicles experienced a significant loss of horsepower, white smoke, and/or a starting problem.
2. Fuel Flow (Rate and Volume) is the most critical measurement in determining if “Prime-Loc” could lead to any failures. Testing reveals that the same amount of fuel is being delivered to the injection pump at the same rate, and that Prime-Loc does not reduce fuel flow.
As mentioned in earlier roundtable statements, the VP44 injection pump is lubed and cooled by diesel fuel. It does require 70-75% of the fuel to be returned to the tank. All testing data provided thus far focuses on pressure, not flow. We have directed our attention to the area of fuel flow testing to ensure the injection pumps are receiving ample fuel for lubricity and cooling. As you will see in the following tests, “Prime-Loc” does not reduce fuel flow, and the injection pump does receive ample fuel.
Fuel Flow Test Results
Over the holiday weekend, our design team tested fuel flow through the system. This test measured the amount of fuel returned to the tank in exactly one minute. Our results are as follows:
1. With no Prime-Loc system, pressure during testing was 8 psi, and 4. 5 lbs. of fuel were returned to tank.
2. With Prime-Loc installed, pressure during testing was as low as 2 psi, and we still returned 4. 5 lbs. of fuel.
Systematic, repetitive testing was conducted on a stock ISB engine at high idle, both with and without Prime-Loc. There was absolutely no difference in the amount of fuel that was returned to the tank.
As you can see above, in both cases, 4. 5 pounds of fuel was returned in the one minute time frame.
Although there was a low pressure reading, it did not cause any reduction in fuel flow, which is the primary concern.
3. Low Pressure Concerns – The fuel flow test confirms that the low pressure does not result in a fuel flow reduction. Fuel flow testing was done when pressure was at 2 psi, and it returned the same volume of fuel at the same rate.
Our pressure testing revealed similar results to those found by the Power Shop.
Our tests were conducted on a NON-“Prime-Loc” equipped ISB 24V 215 hp. engine, that came to a local Cummins dealer with a failed lift pump. Diagnostic testing was conducted using Cummins Insite software that confirmed this failure with a 368 fault code. This code is tripped when lift pump pressure is below 5 psi.
Our team installed a pressure gauge that confirmed this low pressure, and indicted that the lift pump was only putting out only 4. 5 psi. (. 5psi. below minimum required).
The unit was repaired by installing a new lift pump before conducting our tests.
With test equipment still in place, we took our initial readings.
13 psi at low idle
8 psi at high idle
We then installed a “Prime-Loc” PL9899ISB, and conducted different testing comparing pressures with different components in place.
Complete Kit (Check Valve and 28” of #5 hose) – low idle-8psi, high idle-3psi
No Check Valve, Same Hose – low idle-11psi – high idle-5psi.
No Check Valve, and #6 hose and fittings – low idle-12psi – high idle-7psi
Elective Modifications
Our testing reveals that a low-pressure situation does exist; however, it does not reduce fuel flow. If you are concerned with this loss in pressure, you can make some minor modifications to your “Prime-Loc” unit that will effectively bring pressure differential to just a 1 psi drop. These modifications are especially suggested for any vehicles with non-stock, high horsepower engines.
1. Remove Check Valve
On these models, it serves only as a back-up. It was more critical on earlier models.
Directions included below.
2. Upgrade from #5 hoses and fittings to #6 hoses and fittings.
Further Testing Being Conducted By “Prime-Loc”
We will continue to contribute to the industry-wide testing of this situation, and will provide our results until a solution is reached. Testing being conducted this week:
Flow Test under load conditions on dynamometer.
We are very interested to review and discuss any testing you may have conducted. In order to avoid false claims that may cause unnecessary panic to other owners, we would appreciate that you share “Prime-Loc” related information with us prior to its release. Please send all findings directly to Bill Wydra at bwydra@ash-tec.com. Bill can also be reached via telephone, toll free at 888-774-6562.
CONCLUSION
As many of our industry leaders, we feel the problem originates in poorly designed and manufactured lift pumps. Low pressure does exist when “Prime-Loc” is installed, but testing reveals that ample fuel is passing through the injection pump to both lubricate and cool it. As a company, “Prime-Loc” is prepared to continue to contribute significant time and resources toward testing and evaluation of this situation. Please feel free to call with any questions or concerns.
“Prime-Loc” Check Valve Removal
The removal of the check valve on any Prime Loc filter re-location kit can be done either on or off the engine, by using the following procedures:
Please observe all safety precautions while performing this task!
1. Taking a 3/16” Allen wrench, remove the Allen bolt securing the hose adapter to the filter head, then slowly remove hose adapter carefully, so as, not to lose the to two o-rings, if you look in the holes of the filter head, you’ll see the check valve.
2. Next, if not equipped with a gauge, use a 7/16” wrench and remove the appropriate pipe plug which is in line with check valve. If equipped with a gauge, using a 9/64” Allen wrench remove the two Allen screws that secure the gauge to the filter head, and remove gauge carefully, so as, not to lose the two o-rings
3. Using a 5/16” flat nose punch approx. 6” or longer, insert it into the appropriate hole and while holding a rag at the rear of the hole to catch the spring and center, lightly tape the punch with a small hammer enough to dislodge the o-ring. Spring and check valve center will exit the rear of the filter head.
4. After removing the spring and center, use a small wire with hooked end to retrieve o-ring or use shop air to blow o-ring out. If for any reason o-ring can’t be retrieved or blown out, it will be caught by the filter and can be discarded on your next filter change.
5. Re-install all removed components and securely tighten, test run vehicle and check for leaks. If you should encounter any problems, please contact us at 1-888-774-6562.
As always, Ashland Technologies prides itself in providing a premium product that is supported by superior customer service. We have always stood by our products in the past and will continue to do so well into the future. We do empathize with each of you that may be concerned about this situation, and assure you that we are working to determine the root cause and develop a solution.
At this time, our aggressive co-operative research efforts reveal that “Prime-Loc” is NOT THE CAUSE OF INJECTION PUMP FAILURE. We are in agreement with other industry leaders that poor performing lift pumps are the apparent root cause of injection pump failures. With this in mind, we feel this concern is limited to 1998 and 1999 ISB engines. So at this time, all other vehicles should not be at all concerned. Further testing is being conducted, and we will provide status of those results.
Since the first of only three customer service calls received, our team has been diligently researching the problem. We have consulted with Chuck Arnold (The Power Shop), Steve St. Laurent and several others to gather our findings in order to co-develop a solution, and we thank each of you for your input and support. We have also conducted extensive testing ourselves, and will continue to do so until a solution is reached.
Our initial research and testing has revealed the following facts:
1. Lift pump and injection pump failures have been an ongoing problem in several ISB application stemming from School Bus, Motor Home, and yes – Your Dodge Ram Diesel! Details of these concerns can be found in TDR Issue 30, page 52 and 53.
Conversations with Mr. Arnold (Power Shop) reveal that they have seen three failures at their shop, and only one of them was equipped with a Prime-Loc system. The other two vehicles were not equipped with “Prime-Loc” and still experienced a failure. They have a case of a vehicle (not equipped with Prime-Loc) that experienced multiple failures within a thousand miles of travel under heavy load.
In researching other Cummins shops, we have been made aware of a high rate of lift pump and injection pump failures on NON-“Prime-Loc” equipped units. All of these vehicles experienced a significant loss of horsepower, white smoke, and/or a starting problem.
2. Fuel Flow (Rate and Volume) is the most critical measurement in determining if “Prime-Loc” could lead to any failures. Testing reveals that the same amount of fuel is being delivered to the injection pump at the same rate, and that Prime-Loc does not reduce fuel flow.
As mentioned in earlier roundtable statements, the VP44 injection pump is lubed and cooled by diesel fuel. It does require 70-75% of the fuel to be returned to the tank. All testing data provided thus far focuses on pressure, not flow. We have directed our attention to the area of fuel flow testing to ensure the injection pumps are receiving ample fuel for lubricity and cooling. As you will see in the following tests, “Prime-Loc” does not reduce fuel flow, and the injection pump does receive ample fuel.
Fuel Flow Test Results
Over the holiday weekend, our design team tested fuel flow through the system. This test measured the amount of fuel returned to the tank in exactly one minute. Our results are as follows:
1. With no Prime-Loc system, pressure during testing was 8 psi, and 4. 5 lbs. of fuel were returned to tank.
2. With Prime-Loc installed, pressure during testing was as low as 2 psi, and we still returned 4. 5 lbs. of fuel.
Systematic, repetitive testing was conducted on a stock ISB engine at high idle, both with and without Prime-Loc. There was absolutely no difference in the amount of fuel that was returned to the tank.
As you can see above, in both cases, 4. 5 pounds of fuel was returned in the one minute time frame.
Although there was a low pressure reading, it did not cause any reduction in fuel flow, which is the primary concern.
3. Low Pressure Concerns – The fuel flow test confirms that the low pressure does not result in a fuel flow reduction. Fuel flow testing was done when pressure was at 2 psi, and it returned the same volume of fuel at the same rate.
Our pressure testing revealed similar results to those found by the Power Shop.
Our tests were conducted on a NON-“Prime-Loc” equipped ISB 24V 215 hp. engine, that came to a local Cummins dealer with a failed lift pump. Diagnostic testing was conducted using Cummins Insite software that confirmed this failure with a 368 fault code. This code is tripped when lift pump pressure is below 5 psi.
Our team installed a pressure gauge that confirmed this low pressure, and indicted that the lift pump was only putting out only 4. 5 psi. (. 5psi. below minimum required).
The unit was repaired by installing a new lift pump before conducting our tests.
With test equipment still in place, we took our initial readings.
13 psi at low idle
8 psi at high idle
We then installed a “Prime-Loc” PL9899ISB, and conducted different testing comparing pressures with different components in place.
Complete Kit (Check Valve and 28” of #5 hose) – low idle-8psi, high idle-3psi
No Check Valve, Same Hose – low idle-11psi – high idle-5psi.
No Check Valve, and #6 hose and fittings – low idle-12psi – high idle-7psi
Elective Modifications
Our testing reveals that a low-pressure situation does exist; however, it does not reduce fuel flow. If you are concerned with this loss in pressure, you can make some minor modifications to your “Prime-Loc” unit that will effectively bring pressure differential to just a 1 psi drop. These modifications are especially suggested for any vehicles with non-stock, high horsepower engines.
1. Remove Check Valve
On these models, it serves only as a back-up. It was more critical on earlier models.
Directions included below.
2. Upgrade from #5 hoses and fittings to #6 hoses and fittings.
Further Testing Being Conducted By “Prime-Loc”
We will continue to contribute to the industry-wide testing of this situation, and will provide our results until a solution is reached. Testing being conducted this week:
Flow Test under load conditions on dynamometer.
We are very interested to review and discuss any testing you may have conducted. In order to avoid false claims that may cause unnecessary panic to other owners, we would appreciate that you share “Prime-Loc” related information with us prior to its release. Please send all findings directly to Bill Wydra at bwydra@ash-tec.com. Bill can also be reached via telephone, toll free at 888-774-6562.
CONCLUSION
As many of our industry leaders, we feel the problem originates in poorly designed and manufactured lift pumps. Low pressure does exist when “Prime-Loc” is installed, but testing reveals that ample fuel is passing through the injection pump to both lubricate and cool it. As a company, “Prime-Loc” is prepared to continue to contribute significant time and resources toward testing and evaluation of this situation. Please feel free to call with any questions or concerns.
“Prime-Loc” Check Valve Removal
The removal of the check valve on any Prime Loc filter re-location kit can be done either on or off the engine, by using the following procedures:
Please observe all safety precautions while performing this task!
1. Taking a 3/16” Allen wrench, remove the Allen bolt securing the hose adapter to the filter head, then slowly remove hose adapter carefully, so as, not to lose the to two o-rings, if you look in the holes of the filter head, you’ll see the check valve.
2. Next, if not equipped with a gauge, use a 7/16” wrench and remove the appropriate pipe plug which is in line with check valve. If equipped with a gauge, using a 9/64” Allen wrench remove the two Allen screws that secure the gauge to the filter head, and remove gauge carefully, so as, not to lose the two o-rings
3. Using a 5/16” flat nose punch approx. 6” or longer, insert it into the appropriate hole and while holding a rag at the rear of the hole to catch the spring and center, lightly tape the punch with a small hammer enough to dislodge the o-ring. Spring and check valve center will exit the rear of the filter head.
4. After removing the spring and center, use a small wire with hooked end to retrieve o-ring or use shop air to blow o-ring out. If for any reason o-ring can’t be retrieved or blown out, it will be caught by the filter and can be discarded on your next filter change.
5. Re-install all removed components and securely tighten, test run vehicle and check for leaks. If you should encounter any problems, please contact us at 1-888-774-6562.
