vacuum reservoir hose routing

[ScottinTexas]

since we had our 3 weeks of fall in TX I now need to help my daughter get her heater/defroster working (also 4x4 would be great!)

both hoses on the heater box are HOT after it gets warmed up, I can feel a slight amount of flow coming from under the dash at the transmission hump and nothing when we switch to defrost. I do hear the fan switching speeds.

As I always seem to mention, a racoon had made a home in the engine bay as her truck sat for long time before we purchased it. He managed to disconnect a lot of the rotting vacuum lines and nothing is attached to the reservoir ball. I couldn't find anything that showed heater/4x4 vacuum line routing that I could apply.

in this picture

1. The heater hose is a straight run from the firewall to the top connection in the ball ?
2. middle left what appears to be an 'I" does that line got to the intake manifold ?
3. just below in blue is "intake man." over a red fitting, is that red fitting a different connection, does it go to the bottom of the ball ?
4. on middle right, in blue I can't read it, "to cralbe" ???

vacuumBallLabFSJ.jpg

my current condition,
I beleive "A" should attach to the lower reservoir fitting, "B" would attach to a latter picture with "B" marking

resize edit pass side vac resv hose.jpg

resize edit vacuum hoses.jpg

resize edit heater vacuum conc.jpg

any help would be appreciated,

[tgreese]

There is a vacuum diagram here https://oljeep.com/gw/vac/89/89-FSJ-HDC_Vacuum.jpg and also in your 1989 TSM. A quick look does not show a connection to the vacuum ball. However, you can tee in anywhere that there is manifold vacuum. I don't have the TSM, but it may discuss the heater vacuum plumbing and cover the vacuum reservoir there. Note the TSM is written for the dealership techs, and won't teach you what they would be expected to know.

Also suggest you find the mystery connection under the dash and trace it to the heater or whatever. The routing of the lines is not important; just connect the devices that use manifold vacuum ultimately to a connection with the manifold, and those that use ported vacuum to the port(s) at the base of the carburetor.

[letank]

Looking at your pict, the top one is from the 86...

on the vacuum ball the top most fitting is for a small diameter hose, it goes to the heater vacuum hose, probably the one cut off on the firewall

and on the vacuum ball the lower fitting is larger , a 1/4" ID that is where your B hose goes (on the 3rd pict)

your vacuum ball seems to have a plug on that lower 1/4" fitting.

as for the 4x4 it is connected to that mushroom -check valve- and should branch to the yellow/green vacuum hoses, I forgot the layout... but I may have a look at mine, as I need to do some alternator work

[ScottinTexas]

Looking at your pict, the top one is from the 86...

on the vacuum ball the top most fitting is for a small diameter hose, it goes to the heater vacuum hose, probably the one cut off on the firewall

and on the vacuum ball the lower fitting is larger , a 1/4" ID that is where your B hose goes (on the 3rd pict)

your vacuum ball seems to have a plug on that lower 1/4" fitting.

as for the 4x4 it is connected to that mushroom -check valve- and should branch to the yellow/green vacuum hoses, I forgot the layout... but I may have a look at mine, as I need to do some alternator work

The first picture is from a previous post I had found while reading, it's why I can't read what the bottom right hose goes to,

the fitting on the vacuum ball does NOT have a cap, it's the old hose that was broken still attached,

I've seen all the engine vacuum diagrams and watched Dr. Bob's video but haven't seen anything to help me understand the vacuum ball connections,

thanks for the replies, I think with your responses I have cleared the mental hurdle to try to start hooking hoses up,

[letank]

The top pict is from me... ah, ah, here are better ones:

the heater vac line from the top of the vac ball to the far left side of the firewall

HeaterVacLineFSJx.jpg

detail of the vac ball with the 4x4 TC hoses

4X4vacFSJx.jpg

Vacuum4x4FSJx.jpg

[ScottinTexas]

Michel,
Thank you so much for the pictures they really help me put the pieces together,

I'm not near the truck so I can't get pictures for this post and had to find some previous one's off the phone,

A couple of questions,
Not sure what year model the pictures are from, my 89 doesn't appear to have the heater vacuum on the driver's side firewall,

resize edit firewall dr side.jpg

I had originally thought my heater line was under the 4x4 wall connection as labeled in my original post above with " heater ? "
looking at your picture which I have edited I see you have this same connection but it is going somewhere else,
do you know what that is for (since mine is missing ) ?

edited letank vacuum.jpg

[letank]

A couple of questions,
Not sure what year model the pictures are from, my 89 doesn't appear to have the heater vacuum on the driver's side firewall,

I had originally thought my heater line was under the 4x4 wall connection as labeled in my original post above with " heater ? "
looking at your picture which I have edited I see you have this same connection but it is going somewhere else,
do you know what that is for (since mine is missing ) ?

Sorry, my mistake, the pict are off the 85... here is one from an 86 which has the same heater control as yours

Vacuum4x4FSJ86x.jpg

yes the heater vacuum goes to the same spot as the one cut-off in your pict.

and the (green caption ?) dang, I will have to look under the hood figure it out... to be followed after this intermission of unknown length... I am thinking of the control cable for the heater box flapper...

[ScottinTexas]

EXCELLENT !! that is a picture I can work with, I went out this morning before work for a quick look and again couldn't find anything resembling the heater connection. I'll get my daughter after work today and see if we can't get it hooked up,

Thanks
Scott

[letank]

look and again couldn't find anything resembling the heater connection.

Here we go the 86 heater box cable on the firewall, as the HVAC center is in the middle of the dash the cable is located closer to the passenger side

HeaterBoxHeatControlFSJ86x.jpg

The previous cable pict was from the 85 which HVAC is on the left side of the dash, hence the more leftward entry point for the cable, sorry about posting the wrong pict

[Theduke]

I recently discovered that my defrost no longer worked because I had removed the vacuum reservoir (ball) thinking I had deleted all vacuum from my 89 GW. I was wrong. Before I reinstall the reservoir to the firewall I have a question. Is it possible to convert the existing controls to a non-vacuum control for the defrost? I'm already working on a cable system for the 2wd/4wd switch to the transfer case and would love to delete the last vacuum control on the jeep.

[tgreese]

I don't recall anyone doing that. There have been some posts about spiffing up the vacuum controls for the heat/defrost, but nothing about converting to some other kind of servo control. The switch can get leaky, but I think the vacuum servos are quite reliable. Did you search?
https://www.bing.com/search?q=site%3Afs ... uum+delete
Follow this pattern and change up the search terms. Also try searching on IFSJA.org.

The heater controls have a unique vacuum-control switch that directs vacuum to the heat/vent/defrost doors, at least on the earlier models. I expect an '89 is similar. Not sure how you would convert that to mechancal or electrical or whatever. Why this concern with eliminating all the vacuum controls? An under-hood aesthetic issue? This is not a terribly complicated system, and does not seem to have many issues. Plenty of used parts available, if something should fail. JMO - not worth pursuing.

Also, if you wanted to hide the reservoir, fairly certain you can move it under the dash with no issues. Run your vacuum line through the firewall.

[letank]

I recently discovered that my defrost no longer worked because I had removed the vacuum reservoir (ball) thinking I had deleted all vacuum from my 89 GW. I was wrong. Before I reinstall the reservoir to the firewall I have a question. Is it possible to convert the existing controls to a non-vacuum control for the defrost? I'm already working on a cable system for the 2wd/4wd switch to the transfer case and would love to delete the last vacuum control on the jeep.

the later models vacuum control airflow is different from the 85 and older, here is a pict of the central command. the vacuum is fed from the back, you can see the nozzles

[ScottinTexas]

Michel,

Thank you again for the detailed pictures, I attempted to hook the vacuum hoses up and unfortunately didn't get any change, since I figured my daughter needed defrost more than I needed a victory, we took it to the mechanic, he got the 4wd and defroster lines straightened out,

unfortunately when I tested and engaged the 4wd at home it began lurching and clanking (like the gears grinding going in/out of 4wd) and the light never would come on. we only went about 5mph for about 200 yards testing it trying to get it to smooth out, and then picked up a light/moderate squealing sound (much like a speedometer cable would sound)

back to the mechanic, he had only tested the 4wd on the lift, he diagnosed the lurching/grinding as T/C going out and the squealing as the front driveshaft which he removed,

so now in discussion with BJ's about a new 229 since locally no shops have any confidence/interest in rebuilding it,

[letank]

Grinding is more likely the 4X4 not engaging all the way

1) May be the vacuum motor for the 4X4 has gone south... you can test for vacuum at the hose, or move it by hand and feel what is happening.

For our intermission: the reduction unit on the QT of the 74 did act up at some point, I had to crawl and move the lever with a wrench... of course engine in neutral and brake loose so I could mesh the gears by pushing with my foot on one of tire.... a flat spot is recommended for this procedure...

2) or the 4X4 shifter is out of whack... try to move it by hand.... and feel for the vacuum motor motion.... may be disconnect and plug the vacuum line and secure with zip tie(s)

In the end or before all that, drain the TC oil and see if you have shiny silver slime in it.... the silicone from the TC differential...

Probably best to go to a 228 or 208 to avoid dealing with the potential failure of the 229

[devildog80]

Sorry....not hacking the thread. Just trying to help!

There is a guy in San Diego CA with a 229 sitting in his shop, that was working good when removed from his rig, and will give it away for free.

I will find the info if you want, as I just chatted with him on one of these forums about it last week or so.

He had pulled the 258, 4 speed manual trans and 229 out, and believe he was doing an LS swap & auto trans with different transfer case.

Michel,

Thank you again for the detailed pictures, I attempted to hook the vacuum hoses up and unfortunately didn't get any change, since I figured my daughter needed defrost more than I needed a victory, we took it to the mechanic, he got the 4wd and defroster lines straightened out,

unfortunately when I tested and engaged the 4wd at home it began lurching and clanking (like the gears grinding going in/out of 4wd) and the light never would come on. we only went about 5mph for about 200 yards testing it trying to get it to smooth out, and then picked up a light/moderate squealing sound (much like a speedometer cable would sound)

back to the mechanic, he had only tested the 4wd on the lift, he diagnosed the lurching/grinding as T/C going out and the squealing as the front driveshaft which he removed,

so now in discussion with BJ's about a new 229 since locally no shops have any confidence/interest in rebuilding it,

[tgreese]

I don't think Jeep ever offered a full time case (like the 229) with a manual transmission. If it's really a manual, it should be a Dana 20 or a NP208. Part time cases. Full time cases can't take the impact load of a manual transmission.

[devildog80]

Apologize for my error....tgreese you are correct.

Here is the thread in FSJ Parts for sale section, and said he still had the 229 mid December.

FS: 258/727/229 combo

I don't think Jeep ever offered a full time case (like the 229) with a manual transmission. If it's really a manual, it should be a Dana 20 or a NP208. Part time cases. Full time cases can't take the impact load of a manual transmission.