I was wondering why I might turn that switch on. Now I realize I would re-label it to "Increase Rear Height Clearance". When I turn that switch on it changes the tag air spring (airbag) from around 75 PSI to 115 PSI or whatever the compressor is putting out. The net result is the rear end roller by the trailer hitch is about 2" higher giving better ground clearance. I put some mileage on that roller in Duluth and Gallup this summer prior to realizing what the switch does.
Jim,
The “Incr Tag Load” switch will, as you’ve found, distributes the weight to the Tags. This is “supposedly” useful for scales. However, in the practical world, I use it to help the rear clearance (departure angle) for difficult/steep ramps and driveways.
The problem is, which bothers me, is that it will unweight the drives. This makes them spin as they lift off the ground when taking a hard slice for a turn onto a steep street. I deal with this every time, for our street, so I have a lot of experience of what the switch will do.
Yes, there are times when you need to put more pressure on the drives. Unfortunately that is not an option that I have seen.
I did replace the left SMC valve which is part of the tag loading system today, it appears to have cured an annoying air leak. Part of my ongoing compression fitting vs push fitting conversion.
On my coach 701 control panel, a switch at that position is labeled "DECR WT" (meaning "Decrease Weight"?) instead of "INC LOAD"
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Coach 1482 My rough "Load Increase" Plumbing Diagram. Also added the files for the valves used in coach 1482.
Wow Jim...you've done a lot of homework, Good Job!
When I saw your diagram, my first thought was, "Good grief, I'd hope you could get that schematic from Newell!"
The guys at Newell will spend lots of time on the phone troubleshooting but when any diagram availability is requested the silence is deafening. I'm sure they tell their new technicians to crawl through the chassis tracing lines since no schematics are available.