mine has nothing atached to it what is sopposed to be and what does it hook to

 

Hi What year is the truck? I also would need to know what this so called check valve is connected to and where it's mounted. If it's mounted on the air injection manifold that thing with a small tube going into each exhaust port or bolted to the head somewhere usually in the back then it really is a check valve to prevent exhaust gas and noise from getting into the smog pump. If it's mounted on the smog pump then it's not a check valve and needs furthur explanation. Your system may be what they call a pulse air system and then the check valve is usually connected to the air cleaner or its own muffler/air cleaner.

 

its a 1980 f-150 and its connected to the egr plate under my carb and if i plugit with my finger my iengine runs better when i unplug it it soungs kind of li,ke a little exhaust pipe almost

 

I have to guess again. Sounds like there's a plate under the carb that has at the back of it a flange that an EGR valve bolts to. If there's an EGR valve there it should have a little vacuum nipple on it that should have a small vacuum hose on it going to an EGR control vacuum source. I can only guess that the EGR valve is gone and exhaust gas is coming out of the place where the EGR valve bolts up. There's usually two holes in the flange one for exhaust gas and the other for engine vacuum. With a vacuum leak that big I'm surprised that the engine will idle at all. Sometimes the EGR plate under the carb has to be replaced because the exhauast gasses eats up the plate and the gaskets won't seal. Any of this look familiar?

 

D4AZ-9A487-A .. Air Pump Check Valve...screws into the EGR/carb spacer plate.

>>> From the nipple on the air pump check valve (9A487), a curved neoprene smog hose goes to the lower nipple on the smog pump air by-pass valve (9B289). The upper nipple on the air bypass valve has a hose that goes to the smog pump. <<<

 

Mooncricket. I sure am glad Bill added that info. I can't remember seeing a setup like the one he's describing. Sounds like your problem is solved. If the check valve lets too much exhaust gasses back into the air by-pass valve it can ruin the hose and by-pass valve and mayby even the air pump.

 

Curious if anyone can give me some info on this Air Check Valve. I never knew what mine was and it hasn't been functioning for a long time, however, a few days ago, the plate inside that kept the exhaust from going back into the Air Bypass Valve and Smog pump finally burned out and my Bypass Valve melted in half and the hose burned off. Fortunately, it didn't damage the smog pump.

Does anyone know what size of socket the check valve needs? It's really rusted in there and I need to get a better bite on it than an adjustable end wrench can offer. I can get a socket on it now because I was able to tear the whole check valve off with my hands (pretty rusted), and all that's left is the threads and the hex.

*note* I think there's a difference in size, so this is the kind with the threads on the outside, not inside. And my 300 is an '81. Thanks!

 

Hi. Sounds like you should start looking for the tube that the check valve screws on to.
It may be a lot of work to try to save that old tube because of rust. The price of the new tube and valve may be lots but you've got to think of the time it takes to do the job.
Sorry I don't know the size of the hex on the valve.
Dave.

 

D6TZ-9B445-A .. Manifold Air Supply Tube-male end (female end check valve = D4AZ-9A487-A threads on to this tube. The check valve is still available from Ford = list price: $13.20).

Fits: 1976/91 F100/350 & 1980/91 U150 (Bronco) 300 I-6

The manifold tube is no longer available from Ford.

However, the part number = D6TZ-9B445-A for the tube may have been updated (a common thing Ford does), so you might check with your local dealer. I have no refs past 1991.

 

I already bought the new check valve, it was $15 from Napa autoparts. It requires a different sized wrench than the original though. I think the new one is a 1" whereas the original is like a 1 1/8" or 1 1/4". After I tore the old valve off the end, I should be able to get a socket around it, I just don't want to have to keep buying one, drive home to see if it works, drive back and exchange it, etc..etc.. if it doesn't work. I imagine if I can just get a good hold on it, it'll pop free.

 

There are about 10 different check valves. However....there's only ONE check valve for your application = D4AZ-9A487-A (NAPA can cross this Ford part number over to the brand they sell).

This valve has a female end. The manifold air supply tube itself has a threaded male end that's made as a portion of the tube.

The check valve threads onto the male end of the tube. If the check valve comes apart when you apply a wrench, all that's left is the tube with its threaded male end.

If you apply a wrench to the large nut that's on the tube (behind the threads)...you'll twist that nut off, and then you'll need a new tube. That nut is PART of the tube itself.

 

I'm not really sure of the difference between the two, but from my research I believe what you're describing is the air PUMP check valve and what I'm describing is the air check valve. The air pump check valve has two male ends sticking out of each end. Mine only has the air check valve so I'm not sure the difference. As for my application, the valve itself has the nut on it. There are also two different versions. The CA emissions version has a female end on it that screws onto a male end extending from the EGR manifold right below the carburetor (the one that has the ERG Valve bolted to the end of it), non-CA versions, such as mine, have a male end that screws into the EGR manifold. Either way, both of them have the nut on the valve itself, which is what I'm trying to break free after the valve itself crumbled off in my hand.

From my research: Current Ford PN: F3TZ-9A487A

http://info.rockauto.com/getimage/getimage.php?imageurl=http%3A//info.rockauto.com/Motorcraft/CX1486.jpg

The part number you gave me came up with this:

http://info.rockauto.com/getimage/ge...tex/1A3021.jpg

 

Call it what you wish: air check valve or air pump check valve...but they are one and the same, because = 9A487 is the Ford basic part number for the "Exhaust Air Supply Check Valve" = official Ford nomenclature.

I'm looking at the (1980/89 Ford Light Truck Parts) catalog illustration of your setup (section 94, page 6 - 50 state, not just CA). It shows the manifold air supply tube (50 state: D6TZ-9B445-A) that runs along the side of the engine to have a threaded male end. The check valve must have a female end in order to attach to it.

The catalog calls for D4AZ-9A487-A check valve for this location, and I typed this number (like this: d4az9a487a) into FTE sponsor's Direct Ford Parts online parts locator...the number still shows good.

Since you need the valve that threads to the manifold tube, I didn't mention the OTHER check valve..(yes, there are two). This does NOT thread to the tube, but attaches next to the exhaust air supply valve (Ford basic p/n 9F491) on the front of the engine by the valve cover. Ford doesn't show what the end of this valve looks like.

Forget what autoparts stores show for illustrations...go to a Ford dealer and ask them to show you the illustration reference I typed above: 1980/89 Ford Light Truck Parts Catalog: Illustration Section 94, Page 6.

 

AB: my 1980 F-150 had that same type of check valve. When it broke, I used a 1 1/8 socket (if I recall correctly) to remove the remnants of the valve. My air pump was disabled, so I simply installed a pipe plug to fill the hole, and stop the exhaust leak.
One of these days, if they ever start emission testing around here again, I'll have to replace that valve and put a belt back on the air pump.

 

I wasn't meaning to call it what I wish, or tell someone that obviously knows Ford parts very well that they don't know what they're talking about, it's just that every parts vendor I looked at listed BOTH of these parts as separate things. The Air Check Valve was NOT the same thing as an Air Pump Check Valve. They looked similar, but weren't the same thing.
As for my application, again, say what you will, but the valve is what has the nut on it. I can see it plain as day, there is a nut and then threads going into a female opening on the small EGR manifold. The replacement part that I already bought looks identical to what I'm trying to remove and looks like the one I had pictured above with a nut and threads on it.

Rogue_Wulff, 1 1/8" sounds about right. My 1 1/16" ALMOST fit, but just wouldn't go on. The only reason I even had that size was that I found it in the middle of the street while crossing at a crosswalk. =P I'll grab a 1 1/8" socket on my way home and see if that'll get it for me.