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Topic: MJ vacuum operated dana 30 front (Read 453 times)

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  • 1989comanche
  • [*][*][*][*][*]
  • 1989 Comanche P/U
MJ vacuum operated dana 30 front
 ??? Does anyone know what color vaccum line is supposed to do what on a 89 MJ. There are 4 tubes  if my studying is right one is the vacuum source one vent line and one for engage axle one for disengage. I think I have a broken line somewhere. I have checked the actuator on the axle it is cycling correctly. If I apply vaccum to the right  ports it  engages and disengages the collar to  lock the axle. The transfer case shifter does engage the front driveshaft.

  • LowJ
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  • Wheel every damn day.
Re: MJ vacuum operated dana 30 front
Reply #1
All vacuum line are black on mine and all the Comanches I have seen.

What engine/trans/t case do you have?  The 231 does not have a vacuum setup on it.  Maybe you have the 242??  Do you have an all wheel drive option on your case?

I have the hayes manual with a diagram of the lines.  I can try to scan it or take a picture of it if you need?
16 Toyota Tacoma, 87 MJ Chief

  • 1989comanche
  • [*][*][*][*][*]
  • 1989 Comanche P/U
Re: MJ vacuum operated dana 30 front
Reply #2
All vacuum line are black on mine and all the Comanches I have seen.

What engine/trans/t case do you have?  The 231 does not have a vacuum setup on it.  Maybe you have the 242??  Do you have an all wheel drive option on your case?

I have the hayes manual with a diagram of the lines.  I can try to scan it or take a picture of it if you need?
4.0 six ,231 transfer case far as I know  I will climb under and get a few pictures of it

  • 1989comanche
  • [*][*][*][*][*]
  • 1989 Comanche P/U
Re: MJ vacuum operated dana 30 front
Reply #3
Mine are all different colors I got a picture of the vaccum switch plus the lines coming out and the tag in the background. It is a 231 with the vac disconnect high piƱion Dana 30 front end.

  • LowJ
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  • Wheel every damn day.
Re: MJ vacuum operated dana 30 front
Reply #4
I will try to look tonight at my new to me ax15 and 231 and stock ba10/5 and 231 since they arent in the truck.  Those colorful lines are electric stuff as far as I know. 

I dont have any knowledge of a vacuum disco 30, I just removed it from this truck when I got it.  
16 Toyota Tacoma, 87 MJ Chief

  • Rucas
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  • Resident Moater Masher
Re: MJ vacuum operated dana 30 front
Reply #5
The vacuum lines on the tcase are for the 4wd light. When the front collar locks the light will come on in the dash. Trace all the boots for the system and make surenthey have no cracks. I bet that's where the leak is.
Instagram- @mr.buddy.holly

  • 1989comanche
  • [*][*][*][*][*]
  • 1989 Comanche P/U
Re: MJ vacuum operated dana 30 front
Reply #6
The vacuum lines on the tcase are for the 4wd light. When the front collar locks the light will come on in the dash. Trace all the boots for the system and make surenthey have no cracks. I bet that's where the leak is.

The light switch on a MJ is on a bracket under the overflow bottle on the inner fender. Something has to switch the vaccum actuator in and out.

  • LowJ
  • [*][*][*][*][*]
  • Wheel every damn day.
Re: MJ vacuum operated dana 30 front
Reply #7
I just checked my YJ and MJ 231 tcase. That black line is the speedo gear line and not a vacuum line.
16 Toyota Tacoma, 87 MJ Chief

  • LowJ
  • [*][*][*][*][*]
  • Wheel every damn day.
Re: MJ vacuum operated dana 30 front
Reply #8


YJ
16 Toyota Tacoma, 87 MJ Chief

  • LowJ
  • [*][*][*][*][*]
  • Wheel every damn day.
Re: MJ vacuum operated dana 30 front
Reply #9


MJ
16 Toyota Tacoma, 87 MJ Chief

  • LowJ
  • [*][*][*][*][*]
  • Wheel every damn day.
Re: MJ vacuum operated dana 30 front
Reply #10
This is all I can find in the book.



16 Toyota Tacoma, 87 MJ Chief


  • 1989comanche
  • [*][*][*][*][*]
  • 1989 Comanche P/U
Re: MJ vacuum operated dana 30 front
Reply #12
I will try to look tonight at my new to me ax15 and 231 and stock ba10/5 and 231 since they arent in the truck.  Those colorful lines are electric stuff as far as I know. 
They are definitely vaccum lines I have broken most of them and had to fix them. Especially at the transfer case  switch forgot to unplug the lines and snapped every one of them a few years ago had to drill them all out of the connector and glue them all back in. Bad part is the whole harness goes up over the transmission and it is in wire loom or whatever they call the plastic protective tube. I need to unplug the connector and pull the sleeving off to  look for breaks in the tubing. It gets brittle and snaps.

  • 1989comanche
  • [*][*][*][*][*]
  • 1989 Comanche P/U
Re: MJ vacuum operated dana 30 front
Reply #13
Well I figured it out  after hooking a vaccum pump to about 10 different lines I could not find a leak anywhere. They all surprisingly held decent vaccum with a cap or calibrated golf tee in the opposite end.  I noticed the rubber plugger on the axle actuator was awfully loose fitting. I pulled it off and looked at it closer it had swelled up like old rubber things do and wasn't very tight so I cut a couple short pieces of vaccum line and replaced it  works perfectly now. It is the rubber thingy marked 1 on the picture below. Its amazing what 5" of vaccum line will do for you. I have spent probably 10 hours of the last few weeks trying to figure it out.
  • Last Edit: Nov 01, 2016, 11:22 PM by 1989comanche

  • Florpro
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Re: MJ vacuum operated dana 30 front
Reply #14
Glad you got it figured out with little fuss!
Can't fix stoopid!