Author Topic: Emissions Systems: Air pump  (Read 1053 times)

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Offline cad425

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  • Although optimistic - that fuel line is a worry!
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Emissions Systems: Air pump
« on: March 20, 2016, 11:50:06 AM »
Another interesting one for you. The air pump diverter valve - mounted behind the alternator on 425-500 engines - on my 425 is broken. The vacuum operated valve doesn't, and when I removed it, the valve is frozen in position. I'll need a new one, although I havn't noticed anything wrong in driveability, like backfires on deceleration.

There appear to be a few available on E-bay, priced around US$80. Does anyone know how 'generic' the diverter valve is? That is, could I fit anyone with the same mounting arrangement? Mine is GM 7030761 (the part # is on the back of the valve) and it appears there was a different one each year (77-79 at least).

The harder question is: do I need it at all? I could blank off the air pump outlet, and that would be it. I don't think its required under ADR27A, so its a California EPA option as far as I am concerned.  Comments?
1979 Coupe DeVille 425 - project
2014 Subaru Tribeca - dd
2006 Fairmont V8 - the 'other' V8
1996 E220 Cabriolet - belong 'im spouse
1989 Capri Turbo - gone to Canberra

Offline Bruce Reynolds

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Re: Emissions Systems: Air pump
« Reply #1 on: March 20, 2016, 09:24:05 PM »
I don't run the AIR pump in my 500.

BUT, removing it, and the accompanying stuff requires the Alternator being moved rearward to then accept the fan belt from the Crankshaft, Water Pump and Alternator.

It is not a difficult task to perform the alteration.

If you desire to do it, I can guide you through the bracket-alteration making.

Bruce. :devil:
Bruce Reynolds, Lindisfarne, TASMANIA
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
(Past President Modified Chapter)

Offline cad425

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  • Posts: 23
  • Although optimistic - that fuel line is a worry!
  • Location: Sydney, NSW
  • Mood: Optimistic
  • My Name: John
Re: Emissions Systems: Air pump
« Reply #2 on: March 21, 2016, 03:36:57 PM »
Thanks Peter:
Ive talked to a few friends too, and will now eliminate the air system. But I will take the easy way out, and keep the pump there - but blanked off - to run the water pump. Let me see your car at the next event!
1979 Coupe DeVille 425 - project
2014 Subaru Tribeca - dd
2006 Fairmont V8 - the 'other' V8
1996 E220 Cabriolet - belong 'im spouse
1989 Capri Turbo - gone to Canberra