Sometimes I run the chemical jug dry without noticing it on a few jobs. How damaging is this on my chemical pump? Am I damaging my chemical pump or main water pump (340ht)??
The answer depends upon what set-up you have. You did not tell us what model of truckmount you are using. Most likely it will no permanent effect on your main pump. That will still have plenty of water flowing and not be dry even if your stock solution runs empty. It might harm your chemical pump, but probably won't ruin it unless you do that too often. That 5 gasllon solution tank should last most cleaners all day or maybe even a couple days. Just be sure it is full each morning. This should be part of your daily check of your equipment before you leave for the first job. Gas? Oil level? etc.
The rubber diaphragm will overheat and wear out prematurely. Constantly drawing air into the system is not good for lots of parts. Fill your jug.
if it's like the prochem one used on most models today, or the old style HM, the water acts as a shock absorber behind the diaphragm. Without it, and depending on the pressure you're operating at, the pressure will , first, indent the diaphragm, then, eventually drill a hole straight through it. In the event that , a hole is drilled, you will, then pull too much chemical, or when the chemical is gone, you will pull air into the 340ht. Not good for its sills. Like Scott says, unless you're using an A.P.O. on a huge job running non-stop all day long, a 5 gallon head pack should last all day.
