258 Mystery Vacuum Component. What is this?..

brickisred · #1 01-18-2003, 08:24 PM

I have no idea what this is. Can someone enlighten me? I pulled it off a while back when I took all my emissions stuff off and installed
my Weber. It was located on the fender underneath the battery. It's got two ports on the top which were connected to the air cleaner, I think. (Well, one of them was, the other line was just hanging) I've looked around the web and haven't been able to figure out what this is. Anyone??? [img]images/graemlins/burnout.gif[/img]

Rickcomanche · #2 01-18-2003, 08:31 PM

Hi,
That is your fuel vapor storage canister.
Rick[img]images/graemlins/AR15firing.gif[/img]

brickisred · #3 01-18-2003, 09:42 PM

Wow, really? I thought that's what the evaporation canister was for... [img]images/graemlins/shocked.gif[/img]

#4 01-18-2003, 09:54 PM

That is a vacuum reservoir. I have one hooked up to the heater vent controls in the j10.

CJ7Taz · #5 01-19-2003, 03:22 AM

I'd have to agree with the vacuum storage canister although that's the first one I've ever seen that had two nipples. Maybe there's a check valve on one side. That one actually looks like it belongs on something automotive, the old ones were a 1lb coffee can with a bracket welded to it.

#6 01-19-2003, 03:53 AM

That is some kind of vacuum resevoir. I think it it is often overlooked when people are looking for vacuum leaks. I am still not quite sure how it works... but I am sure it shouldn't leak. I sealed all of the seams up with JB Weld on mine. Every one of these that I have ever seen in person has been rusty. I would really like like to know if there is an easy and "universal" replacement for it. Maybe I am wrong, but I think the Carter BBD gets a bad rap sometimes just because this unit is trashed and leaks.

This is not the fuel evaporaion canister - as that is on the other fender and has four ports on it. See: http://www.off-road.com/jeep/tech/258bbd/evaporat.htm .

If you look at this diagram, this unit in the bottom - middle - left. http://www.off-road.com/jeep/tech/258bbd/vacuhose.htm

Hope this helps...

#7 01-19-2003, 05:50 AM

I think the idea is that you need the volume of vacuum(?) to operate vacuum motors(aircleaner flaps, shifters, heater controls)

I was going to bring up the check valve but I couldn't think of how it would work.

Rickcomanche · #8 01-19-2003, 06:08 AM

hi,
I'm still sticking with the fuel vapor storage canister.
The bigger of the two ports went to the air cleaner the other one I'm not sure never followed it to the end.
It was a simple solution to pollution control with cathcing the fuel fumes.
Rick

Rickcomanche · #9 01-19-2003, 08:08 AM

The big one to the air cleaner,the other runs back to two check valves,I think one is a check valve if you flip the truck
the further of the two is a liquid check valve.
Rick [img]images/graemlins/AR15firing.gif[/img]

brickisred · #10 01-19-2003, 08:47 AM

Cool, thanks everyone. But let me ask you this, do I need it? I pulled the stock air cleaner off and don't have anywhere to hook it to. I suppose I could tee it in somewhere. Any suggestions? [img]images/graemlins/tongue.gif[/img]

Not sure how to hook it up to the heater controls...
Brendan, do you have a Weber? Exactly where did you connect this thing?