he means closest to the truck, not the tool. That's where most ruptures happen because of the extreme heat. A good setup is to have your lead come off your heat source and attach a ball valve and a bleed hose. That way you have the ability to bleed out the air before you start cleaning. It's also a good idea to have a cold water hose as well. Years ago, I was being lazy and wanted to fill a small bottle of enzyme from the truck. The bleed hose slipped in my wet,soapy hands and the 250 degree solution it my hand and tore all the skin off. I immediately turned on the cold water tap I had installed and cooled the burn down and finished the job. Later, my wife made me go to the doctor and when he looked at it, he said that was the right thing to do. He dressed it and it ended up healing with no scars.