I found my 4 wheel drive was not working prperly, the transfercase works but the front does not in gauge.
Is there a way to trouble shoot a vaccum problem before buying the motor?

There is a black and red line going into the motor where and at what time is vaccum pressent to engauge the axles and how much vaccum should there be?

I looked over all the lines I could see, and found no problems with any of them, where is the source of this line?

Thanks for any help you can give as we have an ice storm coming this way

David
99 Ram 4x4 5.2l

 

I have never used one but I think I would replce it with one of the cable pull manually operated shift levers.

 

welcome to DF...

download the manual from the Merry xmas thread tacked to the top of the forum... have a look at the assembly and check the vacuum lines going to the CAD. I think there is a check valve in there that may have gone bad. not 100% sure on it but I recall hearing something about one and the CAD. hope this helps...

 

I recently had the same problem, My fix was one of the air lines had collapsed and was not allowing the switch to operate. You need to follow them all the way from the tranfer case to the motor, tough to do with out a lift. There is also an actuater switch on the transfer case that these lines go to, just a plug in type costs about 20$ that can go bad. If those 2 fail the problem is most likely in the pump on the front axle wich is a plunger type system.

 

pull of the hose on the right side and leave the other one on. if one of the lines is cloged you will her a woooosh sound and it should ingage. if it doesnt it might be the wires or the motors bad. PS: it has to be running and in 4x4 when you do this.