how do I inspect a check valve...this thing (2 Viewers)

[g-man]

I bought a new one because I had an exhaust leak from my old and it was so rusty that when I went to wrench it off it disintegrated. The new one looks good. But the valve inside has a little surface rust and seems to be stuck in the middle. Should it be loose? I can blow a little air through it. Do I spray lub in it and try and knock it loose with a drift or just put it on and let the exhaust heat and pressure open it up???

 

[Output Shaft]

I have a brand new one I just checked. I haven't installed it yet. (Not for sale).

When you blow on it on the nipple side with your mouth, the amount of resistance to blow air through it is pretty high. It takes a lot of lung power. Air does not flow through it the other direction.

If it passes this test then it's good.

It's a check valve with some sort of rubber flapper seal. I wouldn't spray any petroleum oil through it in fear that it might degrade the rubber.

A little surface rust on those thin inner cross supports inside the valve shouldn't hurt anything.

 

[Bear Lake Cruiser]

I thought these were NLA. I freshened up an old one by soaking in vinegar.

 

[Output Shaft]

I think I got the last one. They are now NLA. I purchased it 2/2014 and was surprised it was still available. 6 months later I thought I'd get myself a spare. No such luck. All gone

 

[Bear Lake Cruiser]

Gotta wonder what stuff output shaft has rat holed away for a rainy day!

 

[Output Shaft]

I wish. I should have started hoarding 15 years ago... When more stuff was available. I kept putting it off till tomorrow. When tomorrow came... most of it was gone.

 

[Bear Lake Cruiser]

I wish. I should have started hoarding 15 years ago... When more stuff was available. I kept putting it off till tomorrow. When tomorrow came... most of it was gone.

I have a ton of stuff rat holed. But then I have two cruisers with same engine and smog components. F....Jenna just crossed into Baja Sur an hour or two ago. Her and her college roomie. In her Taco with camper. Headed to that secret cove of theirs.

OK thread hijack over

 

[Output Shaft]

Wow!

 

[g-man]

I thought these were NLA. I freshened up an old one by soaking in vinegar.

Sorry, the one I bought was "new to me". Not new. I was able to blow through the piece by mouth with some resistance. I think this is the key to checking the piece. There is no plastic/rubber inside just a metal disc. I thought it might move but maybe it is just stationary like a baffle.

 

[Output Shaft]

Yeah, that makes more sense. It's hard to believe a rubber check valve surviving the heat. All I can see is metal on/in mine too, but the check valve seal is so perfect, I assumed it had an internal rubberish seal. Hmmmm

 

[micruz60]

I've just disassembled the air rails on both the 40 and the 60, each check valve has the rubber disc, the one from the forty seems pristine, still flexy after 190,000 miles. The one from the sixty is stuck, deformed the rubber disc into the pie slices, 304,000 miles, plenty hot miles. The goal is to clean the carbon out and reassemble to one 'best air rail, smog gear' and bag it for reserve.

 

[g-man]

We're talking about another "check valve" micruz60. Look at the pic in post #1. This is mounted to the narrow diameter exhaust pipe that comes up under the drivers side. The attached hose goes to the smog pump. Are you adding this to the conversation? I have attached an SOR diagram of the check valve.

 

[Beachcomber Bernie]

@micruz60 is talking the same valve.
We've got 2 of these NLAs and he was workin on the one on the air rail.

 

[micruz60]

Lucky number 25

I wonder which one gets hotter?

 

[Beachcomber Bernie]

Personally?
That new one Mr. Shaft has. NOS doesn't get any hotter!
Got me all a'twitter.

 

[Output Shaft]

Check valve porn:

This is the check valve we're talking about. Same one used on exhaust pipe and air injection manifold. Air flows in one direction only.

View from nipple side. Black rubber flapper valve CAN be seen below thin cross supports.

View of threaded end. Metal plate (heat shield?) visible on this side.

 

[micruz60]

Yawn.