I have found the best way is to find the main vacuum line. You can take it off the power break booster. Then light yourself a big fat cigar and using your mouth blow smoke into the line. The smoke will identify where the leak is because you can see the smoke coming out. For about 200.00 you can buy the real tool. For less then 1.00 you can get a cigar.
Check with the guys at HeaterTreater. They are the experts. You can follow my user name to my Bio page for a link or search heatertreater on any search engine and you will get there eventually.
the vacuum hose connects to the airbox
NoNo
In line on the heater hoses on the passenger side of the engine. Has a small vacuum line to it and both heater hoses go through it. The heater hoses are smaller than the radiator hoses and go through the firwall.
Its located on the passengers side of the vehicle under the dash right next to the recirculating vent and the vacuum motor...........
No, it is not required. You can remove it and splice the heater hoses together.
Check the vacuum operated valve at the hose going to the heater core.
the vacuum hose connects to the airbox
It goes to the ac/heater control head.
The Haynes Jeep Cherokee 1984 - 1996 book has 7 different diagrams which show how to do that repair.
No.
NoNo
In line on the heater hoses on the passenger side of the engine. Has a small vacuum line to it and both heater hoses go through it. The heater hoses are smaller than the radiator hoses and go through the firwall.
There are several things that can cause heater problems in your 1998 Jeep Grain Cherokee. The most common cause of heater problems is low fluid in your cooling system.
About $600
Yes
That is the vacuum supply for the HVAC control.
Do you live in an area that you need your heater?