Wiper door valve placement

[Jeff A.]

On a 70 Corvette there seems to be a contradiction between the AIM and the NCRS Judging Manual. Can someone end the confusion ? The AIM shows the mounting of the Actuator valve on the passenger's side wheel skirt, but the Judging Manual places it on the firewall near the master cylinder. Who's correct and if it goes near the master cylinder, does it mount on the bracket that is perpendicular to the firewall right next to the power brake booster ? Thanks

[Terry M.]

Re: Wiper door valve placement

Jeff,
There should be no confusion here. The drawing in the AIM was made during the 1969 model year when the actuating valve was behind the passenger side wheelhouse. A little before the 1970 model year SOP (Start of Production) the vacuum harness was changed and the location of the actuating valve changed to the bracket inboard of the brake master cylinder.

Cheer up -- during 1971 production the location of the actuator changed back to behind the PS wheelhouse. I don't think the illustrations in the AIM kept up with these changes, and the guys assembling the cars managed to "go with the flow" and get the parts in whatever place the vacuum harness dictated.

One needs to be aware of the limits of the drawings in the AIM. Fastener head shape and clamp design are just a few of the items in the AIM that didn't always get changed as the parts changed in production. That is just one of the reasons that original cars are the best sources for research.

[Joe L.]

Re: Wiper door valve placement

Jeff-----

First of all, I think that what you're talking about is the wiper door vacuum relay valve. Originally, for the 1968 model year, the valve was in the fender well position. This remained the same for most of the 1969 model year. In late 1969, the valve was moved to the firewall location, roughly inboard of the master cylinder location.

I thought that the valve remained in the firewall location for the entire 1970 model year. However, it may have moved back to the fenderwell location prior to the end of the 1970 model year. I believe that the fenderwell location was used for 71-72 models.

If your relay valve was located on the firewall location there should be a bracket there for it or, at least, some evidence that the bracket originally resided there. If there is no such evidence and the firewall fiberglass appears original, then I'd say that yours was originally located in the fenderwell. In that case, there should be evidence of its location there.

[Jim T.]

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[Stephen B.]

Re: Wiper door valve placement

The wiper door vacuum relay valve on my 1970 was near the power brake booster.

[Jim T.]

Re: Wiper door valve placement

My original owner 70 has the vacuum valve mounted on the firewall inboard of the power brake booster. My 70 was built on July 18th 1970.