Issue link: https://read.dmtmag.com/i/23755
6 6 4 4 Insert the new filter into the housing in the proper orienta- tion — normally with the wider end first — and seat it against the other end of the housing. Install the cap and hold it in place with one hand while fastening the three attaching clips by guiding their hooks over the end of the cap, then snapping their finger tabs back against the housing. The new filter must fit snugly into the housing and seal at both ends. on conical designs. Normally, the larger end goes in first. ? Look inside the cap for a label giving you the part number for the replacement air cleaner. Inspect the rubber seal for cracks or other damage and replace it if not in good condition. Many modern, aerodynamic trucks have a single air cleaner mounted under the hood. These are easy to service but may not offer a lot of capacity for dirt. Older trucks often have dual chrome air clean- ers on either side of the cowl. This setup has two units plumbed to supply equal amounts of air to the engine. Dual, external air cleaners offer a much larger volume of space for a much larger air cleaner cartridge allowing less frequent servicing, especially with two units. This is helpful in dusty condi- tions. Another advantage of these is low restriction because the air cleaners take some time to clog with dirt. The lower the restriction, the better a late-model engine’s performance and the better an older engine’s fuel economy. However, with current high fuel prices, aerodynamics is more important 5 Inspect the inside of the hous- ing for any signs of dirt leaking past the filter toward the center of the housing, which should be free of dust and dirt. If leakage has occurred and the seal in the cap is damaged, replace it. Make sure the new filter’s seals are in perfect condition. SINGLE, UNDERHOOD VERSUS DOUBLE, EXTERNAL AIR CLEANERS: WHICH IS BETTER? than ever. Two factors are involved in deciding which design is right for you. The first is how fast you run. For a long-distance trucking operation where you spend most of the time at highway speeds, running dual external air clean- ers is not cost effective unless you are getting a premium hauling rate. If run- ning locally and on-off road at lower speeds, the additional air resistance may not matter a lot. The other factor is how dirty the air is where you run. In typical highway situations, you should not have unusual clogging of your air filters. If running on-off road as in the case of a dump truck or concrete operation, you might be able to cut downtime significantly running the dual externals. This type of operation often sees lower speeds and wind resistance anyway. 7 Inspect all piping from the air cleaner housing to the engine to make sure it’s in good condi- tion and all clamps are properly installed and tight. Servicing a large, external air cleaner entails additional steps to get to the filter. For example, on a Peterbilt, you rotate the cap, which is retained by sprung washers, in the appropriate direction to unlock it, then pull it up and off. You then re- move three capnuts that retain the air intake screen and filter cartridge retainer. Next, you remove the in- take screen and, then, the cartridge retainer screen, using a rag to pro- tect your fingers. Finally, pull the cartridge out from the bottom. FEBRUARY 2011 TRUCKERS NEWS 27