i want to go through and check all my check valves included in the rats nest and motor. how do i go about doing so? do i need a tool?

 

Use your mouth Check valves make sure the air can only travel one way.

 

I would recomend getting a Mityvac vaccum pump and apply 20inhg of vacuum
in the opposite direction that the arrow is pointing and make sure it holds that
vaccum for at least one minute. The blow test is ok for really bads ones but is not
good for ones that have small leaks. I got my Mityvac at Autozone. They had a
free rental one for use.

jaj1

 

All of mine seemed good using the blow test, hooked it up to a Mityvac and 3 had slow leaks... Since 3 outta the 4 check valves go into the UIM and flow in the vacuum direction, just make sure they hold at least 10psi of checked pressure if your car's mostly stock.

 

Easiest way.

 

Maybe the easiest but it is not a good test.

 

Exactly, your mouth sucks (no pun intended) for this test. You can only generate about 8" of vacuum with your mouth. If you can generate more, you should be a **** star.

You need a full 20" to full test the check valves. I too had a few that passed the mouth test but were bad.

Sonny

 

Damn I read the title and thought you wanted to check your valves. Not your check valves. I was hoping for a roasting.

Any how since I am here I would say if you have the money to buy a vacume tool go that rout but if not you can check them with your mouth. You should be able to blow thru them in one direction only.

 

Your mouth can apply very little pressure/vacuum. You'll want to be sure they don't leak against 10-15psi of vacuum (pressure). A mityvac pump works best for this (and many other things on this car). If you're not interested to do that, then just buy all new replacements from the hardware store. No sense losing the kingdom for the sake of a $3 check valve.

Dave

 

These guys are indestructable:

 

^^ That's what I used, but I got 3/16" barbs instead of 1/8" because the 1/8" felt a little too loose.

Sonny

 

Whoa... fancy-schmancy!

Did you happen to notice vaccum pressure it takes to open those suckers (in the on/open flow direction)?

I had to place some checkvalves in a supercharged Miata to keep pressure from going where it wasn't supposed to go. I used a large one in the ISC breather line that wouldn't open until like 3inHg (obviously should be 0, ideally). When it did open, the diaphragm would actually vibrate, and would sound like a trumpet being constantly blown when the A/C was on. It took me a week to find the source of the noise.

 

can you guys help me find the part # for the 3/16" hose to pipe barb that will fit onto those checkvalves.

I'm having trouble locating, and unsure what fits on what.

Thanks

 

Those are also freaking massive. Either get the OE ones or source another company that will sell you smaller ones at a reasonable price. You figure, the stock ones have lasted *this* long under all the heat cycling and oil it sees, you know they are worth the money.

 

The "mouth test" is ok to check for a total failure of the valve. However, it's best to use a Mitivac for a full test if the "mouth test" passes.