Cummins 5.9 Filters
2006 Dodge 2500 Mega Cab 5.9 Cummins 150K miles Just picked up this fine, clean truck and it has to last me a long time. Would someone please give me the correct Fleetguard air, fuel and oil f...
Forum Discussion
mapguy wrote:
Diesel fuel Filtration requirements for a common rail high pressure system are much difference than the requirements for a low pressure mechanical pump system. Both systems are severely damaged by very small amounts of free water in the fuel.
High pressure systems are damaged easily by ~5-7 micron particulate. Especially if emulsified water is also present.
If you want an eye opening read - go to the Bosch website and research cp3/cp4 series pump systems in regards to fuel specifications.
Caterpillar a few years ago did some extensive studies on diesel fuel filtration needs of a high pressure common rail system. These studies are available on the internet with some searching....
On fuel filtration - you cannot get hung up on the "micron rating". It really is a meaningless number unless you have a few more facts. Like the Beta ratio of the filter. Or the nominal and absolute micron ratings.
Most don't understand that the high pressure fuel system really has two contaminate sources that take differing filter media to minimize the risk of injection system failure.
Particulate
Water
The filter in the previous post, if a FF5320, is a 5 micron @ 98.7% efficiency as tested to SAE J 1985 standard. It also does not protect against water.
The FF5320 is a 2 micron filter, as advertised everywhere, and is installed after a 7 micron filter/water separator.
You can reference any stats you like, but thats the listed specs.
