oldroyale

I bought a 1984 Olds 88 Royale with a 307 cu in engine, with A/C. Inside the engine compartment, on the inner pass. fender is a black plastic ball with only one hose, most likely a vacuum reservoir. The hose attached to the ball was cut off 6" from the ball, the other section of the hose is gone, what did that hose connect to, and it's location.??
Any info would be appreciated.

Yellowstatue

Hi there; Is the ball about the size of a softball or a few inches bigger?? Is it behind the coolant reservoir or just behind the headlight?? I just looked at my '84 Regency (retired) and it has the bigger ball behind the headlight- no hose at all and I don't remember where it went the other cars have the smaller ball and two hoses go through the dash into a dark region I'll try to get a look at the '84 again later today and report back..

72 cutlass455

On my 72 cutlass it was part of the ac system that was taken out.

oldroyale

Hi,
Thanks for the fast reply.
This vacuum Reservoir "ball" (as I named it) is mounted behind the passenger headlight, and in front of the coolant reservoir.
It is larger than a softball, and slightly larger than a toilet float ball. It has two mounting brackets molded on it, along with only one hose connector, which is recessed. The hose was cut off, and whatever it was connected to is a mystery to me.
I've checked numerous hose routing diagrams for 1984, along older and newer Oldsmobile's. I saw 1985 and newer showing a Vacuum Reservoir with two hoses, one hose from the intake manifold (vacuum source), and the other hose going to an inline (vacuum connection) anti-dieseling valve.
According to the 1984 diagrams that I looked at, a vacuum anti-dieseling valve was not shown, neither was the Vacuum Reservoir, or related hose connections.
Perhaps the Vacuum Reservoir "ball" is used for Emission purposes, or Heater/AC, maybe even Cruise Control?
I would like to get it re-connected to the proper factory connections.

Pre-Thank You to any/all who can help me out.

jeffreyalman

I am fairly certain it is for the A/C modes (floor, dash vents, defrost) If your airflow is not changing between these, it is that resevoir's connections

joe_padavano

The 77-90 B-body cars actually use two vacuum reservoirs. One provides vacuum to operate the HVAC actuators during periods of low engine vacuum (like heavy throttle). The other ensures vacuum to the cruise control, idle load compensator, and other vacuum operated equipment. The A/C reservoir is a single inlet ball. There is a check valve in the line feeding this reservoir. The other ball is a two inlet ball.

Yellowstatue

I had another look in the daylight at the '84 and there is no trace of the hose routing, the engine was swapped out and everything is disconnected only one reservoir on this car-the big one- looked at the '81 and '83 and they only have the small ball, the '80 will probably be the same can't find anything in the chassis manual either..

oldroyale

Ok, with your kind help I now know the single hose vacuum reservoir ball is used for the A/C.
The next bit of info I need is--what does the vacuum ball hose connect to, and exactly where is it located?
My "guess" would be that the ball hose originally was attached to a HVAC vacuum control switch.

joe_padavano

Actually, you need one of these:

https://www.dormanproducts.com/cgi-b...tegory_list=:0



The large part of the fitting is a check valve designed to allow the reservoir to be evacuated when engine vacuum is high, but which seals when engine vacuum is low (such as at wide open throttle). The RH end (with the check valve) is connected to manifold vacuum. The center port goes to the reservoir. The LH port goes to the HVAC vacuum supply port.

oldroyale

I found the old check valve behind the carb, the tube connector is broken off where the vacuum reservoir ball hose connects to. I bought a new check valve and vacuum hoses at a local auto store. Tomorrow I will replace the check valve, connect the hoses, then go from there to see what works and what doesn't.
At least the hoses will be connected back to factory connections, then it's a matter of making sure all the HVAC, Emission, and Cruise Control valves are doing their job.
Whoever done the work on this car before I got it really didn't care what hoses went where, and what they were there for.

Thanks for the fast reply of correct info that helped me get this hose business corrected, I really appreciate that.

JamesPDX

Thanks Joe,

The link was not found for the part. Here is a new link to the part.
It is located on the passenger side on top, by the heater and A/C.