Vacuum reservoir replacement?

jhetcel23TJ

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Joined
Jul 3, 2019
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45
Location
Michigan
So in tracing a vacuum leak I disconnected the vacuum reservoir (#5 in the picture below), when giving it a shake there is a rattle coming from inside the reservoir box. Is there a way to test that the reservoir is working properly? What does the reservoir do exactly? And where can I find a replacement if needed?

2003 Jeep TJ, 4.0 I-6.

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Turn the Jeep off, wait a few minutes and then turn the HVAC controls to another setting and see if it still operates. If the reservoir is working it will still operate the vents, if it is leaking they won't work.

It's just an empty container to "store" vacuum.
 
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Well, tested HVAC controls and works just fine. Guess it doesn't need replacement and not the source of my leak.

Do you have access to a mity vac? If not, see if you can borrow one from AutoZone. That way you can pull a vacuum on each component to find the leak.

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So I have a similar issue on mine. I have a '97 TJ with the 2.5L 4-cylinder. For a long time (years) when ever I fire up the Jeep for the first time it will idle fine.

After several minutes it will stutter and almost stall before revving up. During this process I can hear a sound like a chamber filling up. After that is seems to be fine.

If I start driving right away after starting the engine, then I will have a similar stutter and almost stall, then its fine. In this scenario the stutter/almost stall seems to occur once I go over 5-10 mph.

I think this has something to do with the vacuum reservoir under the passenger fender, or a valve of some kind on the manifold side.

If anyone has any ideas I'd love to hear about it!

Thanks!

Ian in NorCal
 
So I have a similar issue on mine. I have a '97 TJ with the 2.5L 4-cylinder. For a long time (years) when ever I fire up the Jeep for the first time it will idle fine.

After several minutes it will stutter and almost stall before revving up. During this process I can hear a sound like a chamber filling up. After that is seems to be fine.

If I start driving right away after starting the engine, then I will have a similar stutter and almost stall, then its fine. In this scenario the stutter/almost stall seems to occur once I go over 5-10 mph.

I think this has something to do with the vacuum reservoir under the passenger fender, or a valve of some kind on the manifold side.

If anyone has any ideas I'd love to hear about it!

Thanks!

Ian in NorCal

Hoping to bump this as I am having the exact issue, with the chamber filling sound as well. When I’m coming to a stop sign and put the clutch in, the idle drops way down and then has a “chh” sound like something is filling with air before the idle comes back. Did you solve this?
 
Hasn’t really been an issue for me but occasionally when I am coming to a stop and clutch in, my idle drops way down. Not sure I have a similar sound, just the hum of an engine wanting to stall. When I come to a complete stop, idle returns to normal. Thought it was a fuel delivery issue but maybe it is vacuum related.
 
This is an old thread to resurface, but there are 2 check valves that I would investigate. The first one is a just off the rear of the intake manifold, and the other is right before the tee that goes into the firewall near the heater hoses & A/C lines. They should hold vacuum in one direction, easy to test with a hand vacuum pump.
 
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