🧪 Dorman 47149 Vacuum Check Valve: Ensuring Optimal Functionality and Performance Review

The check valve I received does not resist one way or the other. I took on the project and spent a lot of time assembling the tank and electronics to run and control the pump and then I opened up this bad guy and it was junk. I then asked for a refund and the price wasn't worth the hassle. Don't waste your time with this.

It seems to restrict air access more than anything else, I hooked it up to my Aoyue repair station to check airflow: open was 5 units, with one-way reversing valve 2 units , in the other direction 0.5 flow units. It was expected that there would be more, for example 4 in one direction and 0 in the other. This doesn't make the heater control work for me, but without a normally working valve my front axle won't turn on.

I added one to replace the factory valve. It started leaking after a few months so I bought two more. One was ok, the other I could suck in both directions. I took it apart and there was a waxy stuff inside, probably to lubricate the caulking rubber patch, but it dried up and turned into little rocks. Let's hope the "good" lasts longer. Every third entry and (possibly) very old stock leads to a bad rating.