Replacement check valve

I need a replacement check valve for the vacuum system. I'm getting tired of freezing my ass off every time I put my foot down and it goes to defrost. Any idea where to get a replacement that will fit? I'd normally snatch one from a junk yard, but it's freezing ass cold here and the closest yard is 40 minutes away. Don't really have the time to run up there any time soon.

The "universal" check valve from the auto stores is about 8x too small.

Why not just fix the vacuum leaks in the reservoir system? Start at the vac ball under the right front of the bumper and work your way back alongside the battery toward the firewall near the heater hoses.

cruiser54 said:

Why not just fix the vacuum leaks in the reservoir system? Start at the vac ball under the right front of the bumper and work your way back alongside the battery toward the firewall near the heater hoses.

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THIS!

A check valve won't fix your LACK of a vacuum reserve.

PS--please be so kind as to ALWAYS post up the BASICS of your XJ--year, engine, etc.

Well, I've got the cruise disconnected, replaced every vacuum line under the hood, hooked the ball up to a vacuum pump to test. I don't have a check valve anywhere in the system, wasn't there when I got it. It goes to defrost whenever I get into the gas pedal too hard. It won't come out at all on the freeway.

97 Cherokee, 4.0, aw4

I've also relocated the ball to the engine bay.

The vents work great at idle and low throttle. Unfortunately, I'm not very gentle on the gas pedal

Go to napaonline.com, select "shop online", select "No" when asked if the part is for a specific vehicle, search "vacuum check valve"--over a page of assorted size valves available.

While the check valve is necessary, I'm surprised that you are dumping ALL of the vacuum from the reservoir, except you admit to a heavy foot on the skinny pedal.

Good luck.

I don't know if the 97s still had heater valves or coolant control valves, but if yours does, disconnect and plug the line to the valve. Believe it or not, a leaking diaphragm in that valve caused the same symptoms as you describe.