Vacuum disco

[ICEBOX]

Anyone have or know the vac diagram for the front disco on a 1990 comanche ?? i have bad lines and I need to replace them . I have founs many diagrams but none are right . any help would be great ! thanks MJ HEADS

[fiatslug87]

This is what I found in the '90 FSM. Hope it helps.

[ICEBOX]

Hey thank you ! .

[fiatslug87]

No problem. It's 100+ degrees here today :cry:, can't do much other than check the board and look through manuals. :papers:

[BLHTAZ]

Now...to save you some time & effort...the best thing you could do is to open the cover and shim the vacuum motor over in to the locked position and forget about it.

 

The other option would be to get a POSI_LOK for it and do away with that worthless vacuum system. There are also quite a few articles out there on building your own Posi-Lok with bycycle cable too. :cheers:

[maddzz1]

Now...to save you some time & effort...the best thing you could do is to open the cover and shim the vacuum motor over in to the locked position and forget about it.

 

The other option would be to get a POSI_LOK for it and do away with that worthless vacuum system. There are also quite a few articles out there on building your own Posi-Lok with bycycle cable too. :cheers:

 

I'm still a little confused about something. So the shift fork or the posi-lok lock both axle shafts togther? and when you switch to 4WD it engages the front drive shaft?

[ORCA]

Once you lock out the front axle, what have you guys done with the vacuum lines coming out of the transfer case? Plugged up the lines somehow?

 

I'm wondering what to do since I swapped in a non vacuum disconnect d30 out of a 95 xj...Sorry to hijack... :hateputers:

[ORCA]

Now...to save you some time & effort...the best thing you could do is to open the cover and shim the vacuum motor over in to the locked position and forget about it.

 

The other option would be to get a POSI_LOK for it and do away with that worthless vacuum system. There are also quite a few articles out there on building your own Posi-Lok with bycycle cable too. :cheers:

 

I'm still a little confused about something. So the shift fork or the posi-lok lock both axle shafts togther? and when you switch to 4WD it engages the front drive shaft?

 

Once you lock the slide fork permanetly the front axle is good to go. The only thing controlling your 4wd then is the transfer case. Someone please correct me if i'm wrong or missing something.

[BLHTAZ]

I just removed the connector from the vacuum switch on the t-case and capped the nipples on the switch with those little rubber vacuum caps that you can get at most any auto parts store. You also have to be sure and plug the vacuum source for the system.

 

Locking the front shafts together is the same thing as having a later model Jeep that they did away with the disconnect on. They have a one piece shaft in them now so there is no reason that you can't just slide the connector over and shim it in place with some washers...plug off the vacuum stuff and forget about it. ;)

[ORCA]

You also have to be sure and plug the vacuum source for the system.

 

Could you elaborate alittle more on this please...? :bowdown:

[CWLONGSHOT]

You also have to be sure and plug the vacuum source for the system.

 

Could you elaborate a little more on this please...? :bowdown:

 

First off, don't worry at all about the Tcase. There is NO vac source there. Its merely a "switch" when you shift into 4WD it ALLOWS vac to run to disco. Which in turn allows the diaphragm to move the shift fork and lock the outer stub axle together.

 

Vac comes off the engine at the pass side fire wall. Just plug the vac line running down to the disco, remove all other lines from Tcase and disco diagram and call it good.

 

CW

[ICEBOX]

Man thanks for the info guys . I thin i will just shim the vac mtr and call it GREAT ! . you guys rock . :bowdown: :cheers:

[BLHTAZ]

You also have to be sure and plug the vacuum source for the system.

 

Could you elaborate alittle more on this please...? :bowdown:

Like CW said above...the vacuum source for the CAD is on the right side firewall so just locate that and cap it off.

 

I only pluggegd the switch ports on the t-case to keep junk from getting in them, but you are right...it really doesn't matter on that :cheers:

[ICEBOX]

OK guys I have 4x4 now. I got a bushing and placed it in were y'all told me to put the washers. works great . THANKS !!!!!!!!!!!!!!!!!!!!!!!

 

 

Any one wanna buy a new vac resivore ?? lol

[BLHTAZ]

:cheers: Excellent...glad to hear it.

 

Put the vacuum stuff on eBay...someone will buy it ;) .

[bobweiser]

Can one of you elaborate or show me pictures of which lines get capped? There are 3 lines that run from the CAD to metal tubing then back to plastic up by the firewall. Then to the transfer case? I am going to shim my CAD over since it's off and want to plug all necessary lines and clean this mess up.

 

Thanks guys.

[mjdoa]

I don't have a diagram for you here at work.

There's one in either Chilton's or Haynes or both.

Have at home,can post up later.

I pulled the harness from the t/case to the steel lines off.Period.

Pulled the harness off the front end of the steel tubes,

followed each line to it's source and capped each one off as I

went.Discarded the harnesses.All is good,except the

4x4 light stays on when there's vaccuum. :roll:

One of these days I'll either trace that line down or

pull the bulb.