72 Eldorado Air Pump - Diverter Valve

[John McLaurine CLC 17181]

Gents,
Putting my 72 Eldo back together.  Come to find out, the AIR pump, more specifically, the diverter valve that attaches to it, will not hold a vacuum.  Anybody know where I can get a replacement?? The usual autoparts websites either dont have it, or have it listed at $222!!

As a last resort, I could gut the internals out of the pump, and just cap the vacuum line.  But I figgered I would at least attempt to find a working replacement first.

Parts catalog lists this as PN 7030761.

thanks
John McLaurine

[TJ Hopland]

I was able to get a new delco replacement about 10 years ago, it only lasted about 5 years and then same thing the vacuum part quit working. Based on the packaging I dont think it was that old at the time. I think even then it was a $60 part.  At the time I thought it was a great deal vs the one I had bought for my 84 Pontiac that was almost $200.  Last time I found mine not working I just removed the whole valve and left the pump alone.   When I did some other work on the engine a few years later I swapped the pulleys to completely eliminate the pump.   Some years and models sold in some areas did have the pump.  They use a single groove water pump pulley and a differently spaced crank pulley so a single belt hits the crank, water pump, and alternator.   You can get metal plugs for the holes in the heads, also I have read that dimes fit nicely.   A vintage pump should be fairly reliable but I would not trust a replacement one to last.  What often kills them (and the valve) is the check valve fails and lets exhaust into the valve and or pump and the exhaust gas corrodes and destroys stuff.   The check valve is that threaded on adapter looking thing between the metal lines that connect to the engine and the hose that goes to the pump.  To test the check valve just pull the hose off the engine side and feel for exhaust coming out the line, there should not be any.  There should be air coming out the hose but not off the engine.  When you decelerate is when the diverter valve should operate and vent the pump air vs. let it in the exhaust.    If the diverter is not working its not really hurting anything, it just make a sort of back fire popping sound in the exhaust. 

["Cadillac Kid" Greg Surfas 15364]

John,
If you don't require absolute originality for any reason, the easiest thing would be to pull the air pump, remove the vanes, and just use it for an idler pulley.  You can of course, cap the vacuum line from  the diverter where it connects to the carburetor, and everything will look just like it came from the factory without the :"sort of back fire popping sound in the exhaust" that can actually take your exhaust system with it.
Greg Surfas 

[John McLaurine CLC 17181]

Hi guys

Even tho I restoring the Eldorado, I think I will just gut-out the pump and cap the diverter valve vacuum port.

The odd part is, this air pump only has coupla hundred miles on it (if that many).  I had just replaced the pump and diverter valve as an assembly about 10 years ago.  Shortly thereafter, I parked the Eldorado.  Hasnt run since.

[collector]

I have an NOS original one if your intersted but its worth some money. Its not the plastic ones which are about the only ones you can get if you can get it at all, its the metal cad plated ones that are used on Corvettes, Ive been saving it for years in the box. Let me know. Without it you will get back fire through the exhaust and blow out your muffler.If you ever look at any car with the muffler all cruched up its because the vavle is shot or isnt working. It needs to be replaced. 

[John McLaurine CLC 17181]

Hi,
Thanks for your offer, but I will pass on the valve for now.

On a related note, does anyone have  a few extra spring clamps for the 1" hose between the AIR pump and the manifold?  One of my clamps is damaged.

thanks
John McLaurine