My New-to-me 1987 CE Wagon

The check valve is under the hood, in the vacuum line from the intake manifold to the vacuum storage ball. It takes longer to open the hood than to change the check valve. It did just occur to me that there is another possible failure mode that can cause this problem, however. On my 86 wagon, the vacuum selector valve on the heater control panel in the dash wore out and started leaking. The loud hissing at certain HVAC settings was the dead giveaway. Under low engine vacuum conditions, the leak was bad enough that the HVAC flapper doors wouldn't hold position. This, unfortunately, does require taking the dash apart, but the good news is that the selector valve is available. I'd try the check valve under the hood first.

 

Thanks Joe. So far I've not heard any hissing noises. Fingers still crossed it's the check valve.

 

Hey Joe,

Guess what! I found a vacuum line disconnected from the main vacuum chamber! I don't know HOW I missed this, but as I was searching around for the check valve, I came upon this line leading to nothing, but facing in the direction of the chamber. I started the engine and, sure enough, there was suction coming from the end of the line. So I hooked it up to the big ball, closed the hood and took the wagon out for a drive. I THINK this fixed the problem. Going up a few hills under heavy throttle didn't deter air flow from continuing through the vents. When I go home, I found the check valve and it appears to be in good shape (no cracks, seated properly with lines connected at all three ports).

Question: Unlike my '75, this wagon appears to have two vacuum chambers, one bigger (the one referred to above) than the other. The smaller one is located at the opposite corner of the larger one, near the A/C (condenser?) above the passenger side fender.
What does this one do as opposed to the larger one on the driver's side?

 

The larger vac chamber is for the cruise control.

 

That's a first for me...I've never seen a GM with a separate vacuum ball for the CC. Teach an old dog (I turned 51 today, BTW) a new trick!

 

The 307 needs all the help it can get. Climb a hill with the A/C and cruise on and the engine needs W.O.T. to make it. Vacuum drops to zero and without the extra vacuum reservoirs, A/C and cruise would both cease to function.

 

There's the rub. I never worked on anything with an Olds 307.

 

Happy birthday Silvertwinkiehobo!

 

Thank you!

 

Sweet Caprice- Hope you enjoyed a summertime's worth of fun with it.

 

Thanks BigBird87! It has been fun getting acquainted with it and I have taken it on a couple of day trips north towards L.A. Get a lot of comments and thumbs-ups too. Despite (or because) it had just 24K original miles on it when I bought it, it did require more than a fair share of service visits to get it to run right. Current project at hand is getting the AC cold again; it just quit on my last week. Turns out one of my hoses sprung a leak; plus I still had R12 running through so a conversion is also underway.

Looks like you have an '87 Caprice too..?

 

The comments and thumbs ups are always nice, but still baffle me a bit as this is a car from my childhood, so I tend to forget time has marched on.
On the plus side with your low mileage car, the suspension, transmission, etc are likely to be in better shape. I am sure you will get the A/C issue fixed. Be mindful of all the vacuum lines and replace them if you can- regardless of mileage.
I have had two. The first one was a yellow gold CE identical to the centerfold for the 1987 Caprice sales brochure, fully loaded. But unfortunately the rust caught up to it. My current one, a Caprice Classic, is the same color, but that is where the similarities end. It is a one owner car with 104K on it, but has strange options. 2 speaker AM non-digital radio (which allegedly didn't exist, no A/C, no rear defrost, non split bench seat all in vinyl, and missing trim that was illustrated in the sales brochure. No power options either for that matter either. It has all the documentation since new, but like I said, it couldn't be more different than my CE, which was just a more comfortable driving car.