When i blow through the larger of the two check valves, they whistle, they also stop air in the other direction like they are supposed to. Do they need to be replaced?

Also, what is the difference between the two check valve types (not including the metal one) and which of them can be replaced with generic cheap ones?

Also, how hard should it be to blow air through the smaller check valves, one is sort of easy, but the one that goes to the pressure tank is really difficult to blow air through, but if i really blow hard it goes through.

thanks

 

^

 

I replace mine with el cheapo from Pep Boys with no problems at all.
They should all pass one way fairly easily and close the other way, if not, it should be replaced.

 

https://www.rx7club.com/showthread.p...t=check+valves

I would use these if you are going to replace them. Better to get hign quality ones that will last. I am going to do this over the winter when I replace my vacuum lines and polish my intake manifold and throttle body.

 

I'm not sure of anyone actually testing the valves to see if they open at different vacuum ratings. I don't remember seeing any information in the manual as far as their operating specs, but that could just be that I missed them.

Unless you have the operating specs and can test them, the only real definitition of a broken/malfunctioning check valve is that you can both through it both directions. If it's closed in one direction but not the other, then technically, it's working. Even the new valves aren't that easy to blow through, however, one person's "easy" compared to another person's "easy" may be completely different.

 

wow those brass ones look like total overkill. i was just going to use these for $3.70 each.

http://www.mcmaster.com/asp/DisplCtl...tlgEdition=109