Tank/Canister behind front bumper???

Hey.....I just got my new front bumper for my 96' 4.0 L Cherokee, that I am going to be putting on this weekend. I went out and looked at the factory bumper and where the mounts are and everything, and on the passenger side, there is a tank/canister set inside the bumper. There is only one line running into/out of it. Not sure what it is and the Haynes Manual does not address it. If anyone could help with what it is...where I can remount it...do I even need it, it would be greatly appreciated. Thanks.

it is a vaccum tank and yes if you wnat your vents and ac to work correctly you need it. put it where ever trips your fancy

You probably need it.

I don't have a 96FSM to verify, but the vacuum reservoir is usually installed behind the front bumper (no, I don't know why either,) and it stored vacuum that is used to control the HVAC plenum valves. The selector you move in the panel is a vacuum switch, and the plenum doors are actually operated by engine vacuum.

If that position is no longer tenable because of your new bumper, it's entirely possible to relocate the thing. You'll need to find a convenient place to put it, and then extend/shorten/relocate the vacuum line to it. Make sure it's not going to leak, or your blower starts doing weird things (although it usually seems to fail to "defrost" when the vacuum cuts out.)

5-90

Thank for the help....I will try to find a place to remount it under the limited hood space I already have, haha....Thanks

I think Jason over at Jeepin.com did a short article on relocating his canister.

I did a shorter one. If it's single chamber, get the vacuum ball from just about any car with cruise control. If dual chamber, then get 2. Move the ball to near the inner fender on the passenger's side and shorten the lines to match. (no brain surgery here folks!)

Ok, then this is a "most likely" issue to look at with my '92 limited not having cruise and just having AC through the defrost? I bought the rig off of a college kid and am I was cleaning out after market wiring when I found vacum lines that led nowhere or just hanging. No cannister in sight but, he had installed a front bumper from JCR offroad. I hope my searching has finally proven fruitful. :read:

This is probably why I also get less than 10 mpg. I have'nt mastered searching but, am learning.

If, anyone wants to volunteer advice I'll buy them a beer if, they ever come to this H_llhole:flipoff:

Reed

F9K9 said:

Ok, then this is a "most likely" issue to look at with my '92 limited not having cruise and just having AC through the defrost? I bought the rig off of a college kid and am I was cleaning out after market wiring when I found vacum lines that led nowhere or just hanging. No cannister in sight but, he had installed a front bumper from JCR offroad. I hope my searching has finally proven fruitful. :read:

This is probably why I also get less than 10 mpg. I have'nt mastered searching but, am learning.

If, anyone wants to volunteer advice I'll buy them a beer if, they ever come to this H_llhole:flipoff:

Reed

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Yes, I think you have found your problem, if the disconnected line is the one that goes across the firewall and along the inside of the right fender, under the battery. It tees off for the heater controls. For starters, you can just plug or crimp off the vacuum line after the tee until you have a reservoir for it. That should at least help engine performance. Often the plastic line rots under the battery tray too, so check that.

Matthew Currie said:

Yes, I think you have found your problem, if the disconnected line is the one that goes across the firewall and along the inside of the right fender, under the battery. It tees off for the heater controls. For starters, you can just plug or crimp off the vacuum line after the tee until you have a reservoir for it. That should at least help engine performance. Often the plastic line rots under the battery tray too, so check that.

Click to expand...

Thanks, Matthew! I think i can find diagrams now. I am so used to working with the S-10 series (am a recent convert to the XJs) that I stay confused as I learn to deal with the XJs.

I was under my XJ this week and would find a vacumme line hung up in the rad support and said to myself....wtf. It would be attached to nowhere!

I am sincerely thrilled that I have a starting point to attack what must be a simple problem for you and that you may not realize it's importance to me.

Thanks for the assistance!

Thanks to all the forum and the seach nazis when it is a bad day!

I just need a little more help if, you guys do not mind. When tracing the lines I discovered this "T" just as you see it. Is this what Matthew was referring to? The cannister is beyond this point?





While lightly touching the nylon tubes/lines while tracing it, I snapped it. I have not searched yet but, would regular flexible lines be ok?

Yes, any vacuum lines that will fit snugly over the plastic lines will work for a repair. And yes, the tee you are showing in the first picture is the one that he is referring to. Connect a rubber vacuum line to it and to a replacement vacuum bottle and that should solve your defrost/cruise problems.

The stock vacuum bottle was bolted to the passenger's corner inside the front bumper. Any vacuum bottle will work as a replacement if you're not concerned about it being in the same location.

Later,
Joe

Crash_AF said:

Yes, any vacuum lines that will fit snugly over the plastic lines will work for a repair. And yes, the tee you are showing in the first picture is the one that he is referring to. Connect a rubber vacuum line to it and to a replacement vacuum bottle and that should solve your defrost/cruise problems.

The stock vacuum bottle was bolted to the passenger's corner inside the front bumper. Any vacuum bottle will work as a replacement if you're not concerned about it being in the same location.......

Click to expand...

thanks again! It is appreciated!

I relocated mine to behind the front crossmember, beside the steering box as to not interfere with the crank. I think I used about 1.5 feet of flexible rubber vacuum hose due to the increased distance from mounting it on the crossmember... I used one of the existing holes on the bottom of the crossmember and drilled another so I could use the origional bolts to hold the canister down.

I too, installed a JCR front bumper but just tucked it up further with a ginormous Zip tie. It has yet to move and is out of sight.
I found this roll of automatic lawn sprinkler line (same diamater as the vacuum lines) on clearance at the local big box home improvement store. It's 100' of excellent replacement line on the cheap.A little more rigid than the rubber stuff but less rigid than the stock stuff. So i went ahead and redid my whole engine bay.It also works well for the washer fluid lines incase one would need to relocate the washer fluid bottle (i.e. snorkel install)

Are you sure that stuff won't close up under pressure?

Lawn sprinklers may be under alot of pressure but there is no vacuum...

I hate to bring this up again and I am sure the veterans are very tired of this issue altogether. I really thought that I had this thing licked about the cc and default defrost mode.

1992 limited, I6 4.0 HO, AT, NP242, D35 replaced with a Chryco 8.25", it had an aftermarket stereo head unit and is now back to stock but, the default defrost action is not my first priority to correct. No vacuum lines have been checked on the passenger side of the firewall.

I know that I do need a vacuum reservoir despite the luck that a few have had with eliminating it and their hvac controls and cc working for them. Local salvage yards are no help, no cannisters anywhere even cracked. I have spent probably 16 hrs searching and some members advised using JB weld. Not my style but, am willing to try anything for a temp. fix. I have gotten the PDF parts lists and FSMs from other sources but, they are not helping me at all. I did run across on thread here during a search that I am unable to duplicate that mentioned a vacuum reservoir from Summit or Jegs and the $32 sounded attractive compared to some $90 dealer prices that some members reported.

I would like to have a cannister before worrying about where cold or hot air is blowing or alleviating the pain of driving without cruise control.

Let me tell you what I know thus far and what I have done to try to trouble shoot it and flame if you must but, I will be glad to assist you with a GM product if, I can.

I have no vacuum reservoir. Removed by a good intentioned US Army National Guard college lad while he was worked up into crawling. Research tells me that lines under the battery are usually suspect from battery acid.

However, I have been all over this thing and.....nada



I start tracing vacuum lines that went to the passenger side inner fender and only found one. It terminated at the cruise control with a T. A line went to the cc servo and the main line was open.



While I was tracing lines, I did break a small vacuum line that went from the top of the egr cannister to the manifold and it is repaired.



While tracing the dead end T at the cruise control servo I noticed a T behind the windshield washer reservoir and took the reservoir loose and didn't see anything amiss.



I replaced 2 lines off of the manifold and thoroughly checked out the main line off the manifold that terminates at the cruise control "T" on the passenger side inner fender.



I went ahead and ran the other manifold lines to make sure they were okay and that I faintly understood their purpose and destination.



I am lost at this point. I understand that the vacuum reservoirs have a minimum of two lines to it. I have read that they usually have two chambers. One for the cruise and one for the hvac. They must have a check valve so it appears that 2 (possibly 4) lines are required at the minimum. I can find no evidence of any other lines that need attention or that are left open. Idle and performance is okay but, what would I know if, it wasn't.

My questions are numerous but, if someone can point me in the right direction, I will do the digging.

Does anyone know how to locate an oem reservoir offered online or a part number to buy one from a dealer?

Would an aftermarket single chamber from Jegs or Summit work?

Am I just screwing up while searching for parts under the available sources offered for Jeep part numbers?

Where in the h_ll would the second vacuum line come from or go to?

Be gently with me but, blaze away if you must I have somewhat of a history in developing thick skin.

Thanks IN Advance,

Reed

How many hoses do you have running to your EGR canister?

Yes, the T connection with the bolt........that'd normally continue to the vacuum canister.

Make sure the main hose to the HVAC controls isn't pinched. Inside of the "L" connection to the vacuum "T" connection, the main HVAC vacuum line was pushed into the L connection too far and eliminated a vacuum from the HVAC controls......I searched for 2 days and then found that line pinched inside of the L connection. Was an easy fix, considering I was just short of removing the dashboard.

Let me check , Sir

Three with what looks like should be an additional one at the rear towards the firewall. Is that what I have been looking for? It appears very unused. I am floored with your quickness!



Dayem!

I only had 2 lines connected to mine, but then I saw a loose rubber hose dangling in the vicinity of the EGR canister......I hope it isn't a vent of some sort, but I slipped it on the last remaining nipple on the EGR. I hope that's right.......

What year do you have?