an old motorcycle riding buddy stopped by yesterday with a problem with his '11 Cherokee (please don't kill this just because it's a Cherokee). anyway, he stopped to ask if i had ever seen coolant that looked line brown jello (once someone knows that you are / were a mechanic, your automatically an expert in every field). so i went out to look, and it wasn't quite jello, but its nothing i would want in any vehicle. i asked him how long it had been that way, he said about 2 weeks. and i eventually got the whole story. he changed his own coolant (flush and fill) but he used Prestone coolant for all vehicles. really he did the whole thing wrong, because his "flush" was using a garden hose from his well. which is also what he used to dilute the coolant as well. anyway, i'm not sure if this is something to do with the coolant itself, or if the main problem is the well water. or both. he wants me to fix this for him, because of the cost of a shops labor rates i'm sure. how big of a job is it to clean this disaster up? is this just a matter of drain, flush a couple of times, drain again and refill? do we need a special kind of product to dissolve what is probably in other places the "sludge" that formed? my idea of a flush is to remove the thermostat, get the car warm, then do a couple of 1/4 mile drag races to really get the coolant pumping thru the system. is this going to be something beyond what we (i am going to make him do the work) can even do at home?