Have a problem I need to know how the vacumm line that comes off the side of the intake goes to the 4 wheel drive and the vaccum that goes into the firewall I've look and look for a pictures and can't find anything any help will be appreciated
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1996 Dodge Ram 1500 Question: 4 wheel drive
Answer #1pushrod December 04, 2013, 23:40Master
Did you look at the vacuum hose routing diagram under the hood? It may help some.
Replyhamptc, December 05, 2013, 03:27Rookie
It just shows were it goes into the intake and that's it I need to know after it comes out the intake
Replypushrod, December 05, 2013, 04:42Master
Ok, you need to supply vacuum to the hvac for the heater and to the transfer case 4x4 vac switch! From the transfer case it feeds a servo that pulls a cable to engage the front differential. So actually you just need to send vacuum to those circuits and go from there, should be hoses there close by, one going into the firewall the other to a reservior then down to the transfer case from the reservior. Is the 4x4 not working? Most common problems are: vacuum leaks, defective transfer case vac switch, hose disconnected to the servo under the battery tray or damaged from acid. The rest of this system gives very little trouble! There are no locking or unlocking hubs to worry with.
cardocIII from Gillespie's Auto Service, December 05, 2013, 04:20Master
It goes to a vacuum reservoir and from there to a vacuum switch on the front of the transfer case. Then the lines go to the front hubs. Do you have vacuum to the switch at the transfer case? Does it maintain vacuum after the engine is turned off? There is a check valve a few inches from the port coming off of the manifold that has to hold vacuum for the system. By the way, this is the same check valve and reservoir that supplies vacuum for the heater controls, so if they work correctly and you can control where the air is coming out of your dash then you don't have to worry about the supply side of the system. There are lots of problems with the switch on the transfer case, the hoses, the hubs and even the splines on the axle shaft that this system engages/disengages.
Replyhamptc, December 05, 2013, 11:42Rookie
I have vacuum all the way to the 4 whell drive actuator after that there's none I replace switch and everything I fill vacuum on the plug that goes on the actuator but after I plig it in I don't fell anything out of the two lines the go to the actuator on the axle