diverter valvr mounting for 75

[Jim S]

Ok, I have a new(nos?) diverter valve, replacement pump, diverter elbow, brackets, etc. Everything went together very nicely until I went to bolt the valve to the elbow on the back of the pump! Is there a .25" spacer that goes between the valve and the elobw; because that looks like that is what's required. I got the elbow from corvette central, and the diverter is genuine delco with right part no. The elbow appears to be the suspect part. When i fasten the valve to the elbow, the crimped flange of the vacuum chamber interferes with the side of the pump.

TIA Jim

[Joe L.]

Re: diverter valvr mounting for 75

Jim----

There is no spacer that I am aware of. However, there are three different elbows and, perhaps, you have the wrong one. Most 69s and all 70-75 Corvettes required elbow GM #3947728. 1976-80 used GM #14010294 and 81-82 used GM #14026170. Make sure that you have the 3947728 elbow. Sometimes, the part number is cast on the part to aid identification.

[Joe L.]

Re: diverter valvr mounting for 75

Jim----

There is no spacer that I am aware of. However, there are three different elbows and, perhaps, you have the wrong one. Most 69s and all 70-75 Corvettes required elbow GM #3947728. 1976-80 used GM #14010294 and 81-82 used GM #14026170. Make sure that you have the 3947728 elbow. Sometimes, the part number is cast on the part to aid identification.

[Jim S]

Re: diverter valvr mounting for 75

I checked the part no. and it's right.

[Jim S]

Re: diverter valvr mounting for 75

I checked the part no. and it's right.

[Joe L.]

Re: diverter valvr mounting for 75

Jim----

In that case, I'll have to do some further research unless someone else can come up with an answer.

[Joe L.]

Re: diverter valvr mounting for 75

Jim----

In that case, I'll have to do some further research unless someone else can come up with an answer.

[Joe L.]

Re: diverter valvr mounting for 75

Jim----

I think I've finally got it figured out and it's about like I expected. 1975 was a "changeover" year for this system and there was a running change made in very early 1975 regarding the diverter valve mounting system. The original elbow was supposed to be GM #3947728, the same as that used on 1969-74 A.I.R.-equipped models. However, very early in 1975, perhaps before any 1975 cars were made with the 3947728 elbow, the part number for the elbow was changed to GM #3951346. This part was then used for all remaining 1975 models and 76-80 models.

In 1983, elbow GM #3951346 was discontinued and replaced in SERVICE by GM #14010294. This part continues to be available for a list price of $12.90.

I'm sorry about the incorrect information I provided earlier, but the GM #3947728 elbow is the elbow which GM currently catalogues as the correct replacement part for 1975 models and, in my office earlier, I don't have access to the much more extensive parts information necessary to sort out a problem like this. This is a case where the GM parts catalog information is wrong. It doesn't happen too often, but it does happen. Especially, for system "changeover" years. The part that you need is GM #14010294.

[Joe L.]

Re: diverter valvr mounting for 75

Jim----

I think I've finally got it figured out and it's about like I expected. 1975 was a "changeover" year for this system and there was a running change made in very early 1975 regarding the diverter valve mounting system. The original elbow was supposed to be GM #3947728, the same as that used on 1969-74 A.I.R.-equipped models. However, very early in 1975, perhaps before any 1975 cars were made with the 3947728 elbow, the part number for the elbow was changed to GM #3951346. This part was then used for all remaining 1975 models and 76-80 models.

In 1983, elbow GM #3951346 was discontinued and replaced in SERVICE by GM #14010294. This part continues to be available for a list price of $12.90.

I'm sorry about the incorrect information I provided earlier, but the GM #3947728 elbow is the elbow which GM currently catalogues as the correct replacement part for 1975 models and, in my office earlier, I don't have access to the much more extensive parts information necessary to sort out a problem like this. This is a case where the GM parts catalog information is wrong. It doesn't happen too often, but it does happen. Especially, for system "changeover" years. The part that you need is GM #14010294.

[Jim S]

Re: diverter valvr mounting for 75

Excellent detective work! I really appreciate your help on this. I'll get the part and let you know how it turns out.

Jim

[Jim S]

Re: diverter valvr mounting for 75

Excellent detective work! I really appreciate your help on this. I'll get the part and let you know how it turns out.

Jim

[Jim S]

Re: diverter valvr mounting for 75

YES........... the new part is the correct elbow for this application. All of you fix your books!

Jim

[Jim S]

Re: diverter valvr mounting for 75

YES........... the new part is the correct elbow for this application. All of you fix your books!

Jim