De-frost is always on (when air is on)

[kastein]

If you are dead set on a brand new OEM one, part number for the pre-97 models is 5200 4366 and for 97+ it is 5503 5902. You can also get them at teamcherokee.com among other places, go to their site and search for "vacuum reservoir". I would personally buy one at the junkyard though, as Joe suggested.

 

[winterbeater]

Or if you want a new one that looks cool........http://www.summitracing.com/search/?keyword=vacuum reservoir&dds=1

 

[tooofast]

I wouldn't expect it too have that much of an effect.

Slightly high idle, loss of floor/dash vents under acceleration (air would shift to defrost vents--default position).

Is your brake booster out? Engine off, pump the brake pedal 4 times then hold it to the floor, start the engine and if the pedal drops then your booster is working.

If you don't like your stopping power you can always upgrade to the later dual-diaphragm boosters of the 95-96.

After reading this last night i looked and both lines from my "ball" under my front bumper we broken. So i moved it in inboard, saving about 3 feet of vacuum tube and hooked it up and boy what a difference to my brakes! :clap:

I just finished the swap in of the booster and MC from a 2000 year and it was good but there was just a little softness in the peddle. Not any more, it brakes more like my Audi than any jeep i have ever had. If only i could get the wrangler to brake as well!!

It the only thing i did yesterday other than the main front (timing case) seal so i guess it had to be that.

Worked for me and I'll post a photo of my red neck relocation of the canister when i get home.

Thanks for the advice, i learn new stuff every day just reading this board!!
Dave

 

[94HOCHEROKEE]

:shhh: waiting for the pics............:yelclap:

 

[94HOCHEROKEE]

Would just taping the end off after the check valve(I think thats what the "T" is) have any ill effects or be a cheap alternative to a resovoir????

 

[winterbeater]

Would just taping the end off after the check valve(I think thats what the "T" is) have any ill effects or be a cheap alternative to a resovoir????

If that was true Chrysler would have left it off and saved millions of dollars.

 

[94HOCHEROKEE]

Thanks for the insight......:kissyou:

 

[joe_peters]

Thanks for the insight......:kissyou:

Is that sarcasm? If not, then the choice of Smiley really scares the Sh*t out of me! LMAO!

Seriously, when at WOT under load you will lose your vacuum accessories--your choice. consider the vacuum reservoir like a prostate, you can get by without it, but life is a whole lot more fun with it.:rof:

 

[94HOCHEROKEE]

Is that sarcasm? If not, then the choice of Smiley really scares the Sh*t out of me! LMAO!

Seriously, when at WOT under load you will lose your vacuum accessories--your choice. consider the vacuum reservoir like a prostate, you can get by without it, but life is a whole lot more fun with it.:rof:

Definite sarcasm. thanks again joe...... I can't find one new anywhere so i guess i have to go to the scrap yard.

 

[joe_peters]

http://www.teamgrandwagoneer.com/cgi-bin/partsSQL/search.cgi?query=vacuum+reservoir&catid=95

Team cherokee has the "large" ones, there are others about the size of a softball.

 

[bigblueishness]

So what all is involved in the vacuum resovoir, what are all the parts used with the vacuum resovoir

 

[joe_peters]

Reservoir, mounting bolts (2), vacuum line.

 

[bigblueishness]

I thought I would ask the question wrong, I will try again, I heard that the reservoir help controls the cruse control, is that true? Is there anything else that works with the reservoir.

thanks for the reply though

 

[joe_peters]

That would depend on your XJ.

If you have 1991 and earlier with an NP231 you may have a D30 CAD (vacuum) axle. Without a reservoir it may engage, and give you 4wd, but under load it will disengage and leave you in a bad way.

I'm not sure in what year the coolant control valve was eliminated, but it too is vacuum operated.

Your various control doors in the heating/cooling system are vacuum operated. Without vacuum the default position is defrost. Under WOT and/or heavy engine load without a vacuum reservoir all air flow will be from the defrost vents.

Cruise control, brake booster, these are also effected.

 

[desertred]

I still have a curious issue with my HVAC control system. Just like the OP, my HVAC will blow out of the defrost vent on occasion. The oddity is that if I depress the clutch or step on the brake (88XJ with Peugeot tranny) the HVAC will revert to the set direction (vent, floor, whatever). At that point it may or may not redirect itself to the defrost setting. This has been ongoing for a few years. Still haven't figured it out. I have checked the vacuum lines and have not found any apparent damage.

 

[joe_peters]

I still have a curious issue with my HVAC control system. Just like the OP, my HVAC will blow out of the defrost vent on occasion. The oddity is that if I depress the clutch or step on the brake (88XJ with Peugeot tranny) the HVAC will revert to the set direction (vent, floor, whatever). At that point it may or may not redirect itself to the defrost setting. This has been ongoing for a few years. Still haven't figured it out. I have checked the vacuum lines and have not found any apparent damage.

Both actions, depressing the clutch or stepping on the brake, are going to effect engine vacuum.

Depressing the clutch removes the load on the engine, vacuum will increase.

Stepping on the brake is also removing load on the engine, while it is also using vacuum stored in the booster but not coming directly from the engine.

When enough vacuum is restored the heater/cooling vacuum motor will attempt to return to the switched settings.

As for not always returning, I have had numerous vehicles when you switch from one mode to the other they sometimes fail to change. I usually just turn off the fan and then back on and it changes.

I would get a vacuum tester and check your system. Also, make sure that someone hasn't put a check valve in your system and put it in backwards.

 

[bigblueishness]

thanks joe_peters for takin your time givin help and advice