4wd in reverse only

Hi Guys ,hopefully some one can help .I searched threads but could not find any thing that fit my problem .
4wd will engage in reverse only ,the light on the dash lights up ,and vacuum actuator is moving when you push the 4wd switch .
As soon as you put in a forward gear the light goes out on dash and the actuator does not work.
I cant see it being a vacuum problem because the actuator does work in reverse.

Any suggestions would be appreciated .

 

Check the vacuum valves for the transfer case

 

can you tell me where they are located and what they look like ?

 

i have a pdf of the 4x4 vacuum system if you want it. pm an adress to email

 

Hi ttc,i tried a pm with no luck, so here is my email ryley97@telus.net
Thank you .