The 90 Cherokee has a vacuum bottle with a connection for the heater/ac control at one end and the cruise control at the other end.
I assume that the bottle has a partition to hold vacuum for either the heater/ac control or cruise control separately.

The later Cherokees have one connection at each end and I assume that the entire bottle is used to hold vacuum.

Am I correct that the later Cherokees have manifold vacuum attached to one end and the heater/ac control and cruise control are connected to the other end through a tee fitting.

 

Here's the diagram for "later" XJ's.

So the intake manifold is at one end of the vacuum line, and the reservoir is at the other. The HVAC and CC "T" off the main line. Also note the location of check valve.



On Renix, there is a single vac line that runs all the way down to the vacuum reservoir. There it splits off to the 2 sides (HVAC and CC). Then individual vac lines come from each end to their respective system. You can see the white T that splits to each side with the large hose. The thin hose in the pic then runs to the either the HVAC or the CC. Don't recall when I removed it from the JY Jeep.. There is no check valve at the manifold.

 

Thanks Saudade.

Yes, on my 90XJ there isn't a check valve. I wonder why since it wouldn't do any harm.

 

On the 90, the check valves are part of the reservoir.

If 4wd, there is also a split near the blower motor for the vacuum disconnect

 

I received the later vacuum bottle and a check valve today (gotta love Amazon next day delivery).

Got everything installed and it works great.

No more having the a/c switch from front vents to defroster vents under low vacuum (accelerating) conditions.

Many thanks.