Off Road Vehicles banner

cad vacuum question

1781 Views 15 Replies 11 Participants Last post by  GOD RAM IT
I hooked up a vacuum tester to one side of the cad and the 4-wheel drive side vacuum line and had vacum on the other side is this supposed to be this way or is the diaphram gone?

Also what is a good posi-lock?
1 - 16 of 16 Posts
just plain "posi-lock". just has a button/knob a$$embly w/ a cablel attatched. but that is the name of the brand.
Posi-Loc just came out with the Perm-Loc and I installed it this weekend. No cable just locks the collar so both axles are engaged all the time. So all I have to do is pull the tcase into 4wd and it is engaged.

http://cgi.ebay.com/ebaymotors/Dodg...ewItemQQcategoryZ33731QQitemZ8020658249QQrdZ1
isnt it bad for the street because the front is always locked?
I read there site and it says its bad

back to the more inportant qustion about the vacuum
Yes you should have vacuum to one side or the other all the time. When you switch the truck into 4wd, the vacuum will switch from one line to the other. Basically one has vaccum in 2wd and the other has vacuum in 4wd.
sorry I guess I worded this wrong

I hooked the vacuum tester to the dshift motor on the opposite side that I had the vacuum hooked to and still was gettin a vacuum reading.
What I have done is to pull the CAD out of the axle and have someone start the truck with the shifter in 4WD. Before starting the truck, the shift fork will be towards the passenger side. With the truck running, the CAD will pull the shift fork to the drivers side. Check the shift fork and make sure the wear pads are on each end of the fork. If these are missing, you will have problems shifting the collar far enough.
if you put the tester on the 2wd side of the actuator, then put it into 4wd, I would imagine that you would get a little vacume, simply because you have sealed that side of it, and the engine vacume is trying to move the diafram to the 4wd side(basically, making the 2wd side bigger, and because it's sealed with the tester, it's going to show some vacume.)

here's how I'd do it,
with the truck in 2wd, and the engine running, remove the vac line that engages the CAD unit, and put the tester on that (4wd) side of the actuator. there should be no vacume.
then, reconnect the vac lines and put the truck in 4wd(make sure the shift fork has moved before continuing). remove the vac line from the 2wd side of the actuator, and attatch the tester. again, there should be no vacume.

sorry if this doesn't make much sense, if someone knows what I was trying to say, and can explain it better, please do.
On 2005-12-12 13:56, lukee1982 wrote:
I read there site and it says its bad

back to the more inportant qustion about the vacuum

I think you need to re-read. dipstick.

The perma lok eliminates the CAD while performing the same function.
On 2005-12-13 04:06, lukee1982 wrote:
sorry I guess I worded this wrong

I hooked the vacuum tester to the dshift motor on the opposite side that I had the vacuum hooked to and still was gettin a vacuum reading.

No, the diaphragm is shot...you need a new one...you should be able to apply vacuum to one of the ports and the other should only move a small amount of air (enough for the diaphragm to move)...once it moves there should be no additional leakage out that port.

If you have a guage, you should be able to put a little vaccum on it and the guage not drop...the diaphragm should not leak to the other side.

The posi loc...I have limited experience with them...but the vaccuum diaphragm will cost you about $160 from dodge...I do not know if these are availible to the aftermarket yet. Or you can get a used one from someone...just make sure you take your vaccuum tester with you to make sure it doesn't leak!

steved
2
The FSM Troubleshooting flow charts.

[img=441x600]http://www.walt-n-ingrid.com/images/photopost/data/542/medium/1chart1.jpg[/img]

[img=431x599]http://www.walt-n-ingrid.com/images/photopost/data/542/medium/1chart2.jpg[/img]
See less See more
well I had the vacuum tester hooked up b4 it switched but didn't think about the possibility of having vaccum due to diaphram pulling till I got the truck out of the garage.
On 2005-12-12 13:54, chllngr73 wrote:
isnt it bad for the street because the front is always locked?

its bad only if you have a front locker that is engaged (elocker or arb, etc that is turned on) or an auto locker (lcokright, detroit, etc)

in 2002 they eliminated the CAD all together
On 2005-12-13 09:03, The Boss wrote:


its bad only if you have a front locker that is engaged (elocker or arb, etc that is turned on) or an auto locker (lcokright, detroit, etc)


Thats why I told him to re-read.

[/quote]
in 2002 they eliminated the CAD all together
[/quote]
Dont the new trucks have the CAD back in them?
1 - 16 of 16 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top