| Author |
Message |
Bill V. (Doc)
Junior Member
Username: Doc
Post Number: 172
Registered: 9-2001
| | Posted on Saturday, October 26, 2002 - 5:46 pm: | |
Mission accomplished--had to cut the nut off with a Dremel tool . As expected, once the cut was made I was able to spead it a bit with a screwdriver and it then unthreded easily. Thank you all for your help.
By the way, the GM ( AC Delco ) part # is 220 48212 and cost me $20 at a Chevy dealer. Aftermarket parts are also available for as little as $10 at Advance Auto, but i went with the Delco part just to be sure. Either way, these prices are a far cry from $63 at Ferrari dealers. |
Lawrence Coppari (Lawrence)
Member
Username: Lawrence
Post Number: 329
Registered: 4-2002
| | Posted on Wednesday, October 23, 2002 - 10:55 am: | |
Get yourself a Dremel tool with a little abrasive wheel and carefully cut the nut on the valve portion. Cut a line in the axial direction on one of the flats. This will get into the threads a tiny bit, but it should enable you to get the bugger off. I had to do that to my front one. The abrasive wheel I'm speaking of would look like a washer.
Or rent a gorilla from the nearest zoo and teach it how to use a wrench.
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Bill V. (Doc)
Junior Member
Username: Doc
Post Number: 171
Registered: 9-2001
| | Posted on Wednesday, October 23, 2002 - 6:45 am: | |
Well, i tried to get the damn thing off and it won't budgeThe main problem is getting at it so some meaningful torque can be applied ( this is the front check valve). Any tips on removing this sucker? |
Bill V. (Doc)
Junior Member
Username: Doc
Post Number: 167
Registered: 9-2001
| | Posted on Tuesday, October 22, 2002 - 11:53 am: | |
Thanks again, Lawrence. I think I got the picture now. I'll give it a rip tonight. I'll let you know what happens. |
Lawrence Coppari (Lawrence)
Member
Username: Lawrence
Post Number: 327
Registered: 4-2002
| | Posted on Tuesday, October 22, 2002 - 8:02 am: | |
I am in the office now. If you wish I could look at my '87 328 tonight to tell you which way to turn it. Which one are you talking about, the front or rear one?
But I will say this from logic. The nut closer to the exhaust is the holding nut - keeps torque from breaking off the tubing. The threads are attached to this nut. Therefore if you stand on the other side of the valve (from where the air source is located), you would turn the other nut (closer to you and part of the valve) CCW to loosen it.
The things can be difficult to get off. I used two wrenches positioned close together. That way I can squeeze them together. That saves knuckles when the thing comes lose and applies torque more precisely. You do not want to break the tube. |
Bill V. (Doc)
Junior Member
Username: Doc
Post Number: 166
Registered: 9-2001
| | Posted on Tuesday, October 22, 2002 - 7:04 am: | |
So far, i haven't been able to make the locknut budge. I'm soaking it again today and will try again tonight. At the risk of sounding dumb, I just want to be sure that I'm turning in the proper direction. Lawrence, according to your directions, I assume that the locknut locks against the the opening of the air rail and not the valve itself. Is that correct? In looking at mine, one can't tell--the locknut is wedged directly between the the rail and the valve with no threads showing either way. I've tried to turn it away from the rail and toward the valve to loosen--I believe that's what you meant (?). |
Lawrence Coppari (Lawrence)
Member
Username: Lawrence
Post Number: 326
Registered: 4-2002
| | Posted on Monday, October 21, 2002 - 6:02 am: | |
Careful with your orientation on the turning of nuts. You turn it counter clockwise to loosen when the head is closer to you than the threads. Vice versa when threads are closer.
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Bill Sebestyen (Bill308)
Member
Username: Bill308
Post Number: 385
Registered: 5-2001
| | Posted on Sunday, October 20, 2002 - 8:15 pm: | |
Bill V.
It's a standard right hand pipe thread. Turn it counter clockwise to loosen it. |
Bill V. (Doc)
Junior Member
Username: Doc
Post Number: 164
Registered: 9-2001
| | Posted on Sunday, October 20, 2002 - 7:42 pm: | |
Good idea, Tim--i'll likely soak mine all night as well before attempting removal. I presume that the nut between the valve and the air pipe nut is a lock nut (?).Am I correct to presume that that is loosened by turning it clockwise , ie away from the airpipe nut and toward the valve? |
Timothy Fulmer (Tf308)
New member
Username: Tf308
Post Number: 12
Registered: 5-2002
| | Posted on Sunday, October 20, 2002 - 7:31 pm: | |
Bill...to answer your question about removal...mine was so rusted that the valve broke in two..leaving just one end on the air rail. I soaked the part still attached to the air rail w. liquid wrench over night. It came off pretty easily the next day w. the 1 inch wrench. If it is a GM part..that explains the english units. |
Bill V. (Doc)
Junior Member
Username: Doc
Post Number: 163
Registered: 9-2001
| | Posted on Sunday, October 20, 2002 - 7:30 pm: | |
Donny--thank you so much. Until now, the lowest price I could find was $63! |
Donny Bridges (Wildcatfans)
Junior Member
Username: Wildcatfans
Post Number: 88
Registered: 9-2001
| | Posted on Sunday, October 20, 2002 - 7:27 pm: | |
The number from a GP Sorensen part is 779-2929 Air Pump Check Valve from Auto Zone. |
Bill V. (Doc)
Junior Member
Username: Doc
Post Number: 161
Registered: 9-2001
| | Posted on Sunday, October 20, 2002 - 7:12 pm: | |
I'm very interested in finding out the GM number for this part ( or at least which GM cars it fits), if any of you have them available. Thank you for all of the input, as usual, gents. |
Donny Bridges (Wildcatfans)
Junior Member
Username: Wildcatfans
Post Number: 87
Registered: 9-2001
| | Posted on Sunday, October 20, 2002 - 2:12 pm: | |
My check valve failed while driving it from Denver to Baton Rouge, when I bought it. I got to Oklahoma City when the slow down light came on, which I'm assuming is because the cat needs the fresh cooler air mixed with the exhaust. Anyhow, the car got to ride the rest of the way home on a car hauler.
Lawrence and Bill are correct. You can get the part from Auto Zone for $13 and it's a GM part. If you have trouble finding, let me know. I may have the box with the number on it.
Wish I had all this info when I was in Oklahoma City! |
Bill Sebestyen (Bill308)
Member
Username: Bill308
Post Number: 383
Registered: 5-2001
| | Posted on Sunday, October 20, 2002 - 9:36 am: | |
Bill V.,
The check valves on my 78 GTS are GM parts and likely so on your QV. They are likely available from your local auto parts store for maybe $20 each. The large fitting (nut) on the air horn side is welded or brazed to the air horn so use a large wrench to hold it still while you use another wrench to turn the check valve nut. Failure to hold the airhorn side fixed will cause damage to the airhorn. I believe these are standard pipe fittings, but I'm not sure. They are a normal right hand thread though.
These check valves prevent hot exhaust gases from flowing into the rubber connecting hoses leading to the diverter valve, where they will likely cause damage.
If the air injection system is disabled, the air injection nozzles inside the exhaust ports will degrade quicker without the benefit of the cooling air flow. In time, they will distort and likely cause an increased flow restriction and make removal or replacement more difficult. |
Lawrence Coppari (Lawrence)
Member
Username: Lawrence
Post Number: 322
Registered: 4-2002
| | Posted on Sunday, October 20, 2002 - 9:23 am: | |
On a 328 the purpose of the air injection is to help warm up the cat faster. When the engine is cold (coolant) a vacuum valve is opened allowing the exhaust to utilize its scavenging effect through the two check valves - one for each bank of cylinders. The scavenging draws fresh air into the exhaust manifold thereby providing extra oxygen. This allows the cat to heat faster. When the engine reaches a certain temperature, the vacuum closes the inlet to the check valves so it can no longer reach the exhaust manifold. The fresh air comes from the bottom of the air filter box. It runs under the intake manifold where it attaches by "T" (after passing thru vacuum valve) to check valve lines. It is the same principle as the older air injection pumps that ran off the fan belt.
A GM part will fit. In fact it may be a GM part. I buy them at Advance Auto for about 12-15 bucks. They can be hard to get off. Once I had to slice one of the nuts. It is a right hand thread. Put antiseize on the new one. You could leave it off the car but it will cause the engine to make a gurgling sound and release some exhaust gases in engine compartment. They would be hot and could cause unpleasantness.
When you remove it, be careful. You must restrain the end of the thing (other nut) where it goes to the exhaust manifold so you don't break the tubing at the engine block. If you break it, get your wallet out. |
Bill V. (Doc)
Junior Member
Username: Doc
Post Number: 160
Registered: 9-2001
| | Posted on Sunday, October 20, 2002 - 8:42 am: | |
Thank you, Tim. That's a good question--I would imagine that it would affect the functioning of the cat in some way, but I don't know for sure how. Anyone out there know what would happen by disconnecting the air injection system? Also, I'm still looking for advice on removal of the check valve--has anyone had a problem with the threaded part breaking off during removal? |
Timothy Fulmer (Tf308)
New member
Username: Tf308
Post Number: 11
Registered: 5-2002
| | Posted on Saturday, October 19, 2002 - 9:08 pm: | |
the diameter of the wrench that fits is 25mm. A one inch wrench also fits. Cant remember which way it turns. What would happen if we disconnected the air injection system? |
Bill V. (Doc)
Junior Member
Username: Doc
Post Number: 159
Registered: 9-2001
| | Posted on Saturday, October 19, 2002 - 8:26 pm: | |
I just discovered that one of my check valves for the air injection system on my car is rotted out and I need to replace it. I have a few Q's in this regard. First of all, the nuts holding this thing on are huge--does anyone know the sizes? Secondly, in what direction(s) do I turn these nuts for removal--especially the 2 which are together on the air pipe side? The best price I've found so far for this part is $63--anyone know of a less-expensive source? Also, is this a part which may be found on other cars, such as Fiat, etc.--I can't make out the serial numbers on it--does anyone know that? Finally, someone suggested that cutting thevalve apart for removal may be easier in that the once they've rot ted they're a ••••• to get out. Any assistance would be appreciated. |