Do all cat 312's have a control function switch (valve)? Where is it located? Thanks
If you are asking about a Pattern changer switch, mechanical or electric ...... NO, they don't, and if it has one, chances were it was owner installed, ...... the newest 312's can be had from the dealers with a mechanical switch as an option, as in the case of my 320 CLU it had to be mounted in front of the rad behind a lockable door, they claim'd that Cat/dealers will not accept the responsability of an accidental "OOPS" I hit the switch in the cab accident .... so you have to pull out a 1/2" wrench and back off the bolt and move the switch and retighten the locking bolt ........ Hope this helped ......:drinkup
I have an '03 315CL that is equiped with a pattern changer. It is mounted behind the cab, and must be accessed by openning the driver side access panel. Look for a block that has pilot hoses attached to it, and it will have a lever (about 2" long) with a hole in the end, that will accept a set screw (it's a bolt actually, with a 1/2" head). As was described above the screw must be removed, then the lever can be set to the other pattern (or patterns-I've heard). The lever has some resistence so, in my opinion, the set screw is not mandatory. I don't see it changing positions on it's own. I think that the majority of Cats are ordered from the factory, by the dealers, with this option so it has become fairly common. If you have a manual it should tell you where to find the pattern changer. If it is a 312 (not a "B", "C", or "D") the pattern changers were a lot less common back then, so the chances of yours having one will be slim.