Section 5.11
Fuel Filter Life
The fuel system consists of three main filters. The prefilter has the task of filtering material down to 100 micron. The coalescer or water separator has the function of separating out emulsified water, and can be considered to be a 10 micron filter. The final filter is rated at 3-5 micron. Generally the final filter is the filter that reaches the pressure limit first. With the current configuration all filters are changed at the same time. The pressure limits when all filters are to be replaced are listed in the chart that follows.
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Filter Pressure Limits |
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RPM |
Normal Pressures |
Replace Filters Using J-48876 Priming Port Gauge |
Replace Filters Using J-48706 Gauge Set (LPP Outlet Value) |
|
600 RPM |
70-115 PSI |
>115 PSI |
>115 PSI |
|
1800 RPM |
100-150 PSI |
>150 PSI |
>150 PSI |
Section 5.11.1
Replacing Fuel Filters
Replace as follows:
- Install J-48876 or J-48706 test gauge(s).
- Start engine.
- Monitor pressures at 600 RPM.
- If the pressure is >115 psi at the priming port or the LPP Outlet, replace filters.
- If the pressure is <115 psi at the priming port or the LPP Outlet, go to next step.
- Monitor pressures at 1800 RPM.
- If the pressure is >150 psi at the priming port or the LPP Outlet, replace filters.
- If the pressure is <150 psi at the priming port or the LPP Outlet, filters are OK.
- Turn OFF engine.
- Remove J-48876 or J-48706 test gauge(s).
| DD15 Fuel System Technician's Guide - DDC-SVC-MAN-0037 |
| Generated on 10-13-2008 |