Technical Vacume

Can the va***e modular and va***e advance be connected at same source?
Turbo 350 and 454 chevy.
Thank you
Terry

 

Vacuum modulator runs at manifold vacuum. Advance runs at port most times. Other wise no problems.

 

The only other issue might be poor signal if running both from the same source. It's a big engine and both 'pots' or chambers are fairly small so it shouldn't be an issue. I would not gang up a brake booster (big chamber) or PCV (constant leak) if possible.

It's Vacuum, BTW. Might make it easier to search that way.

 

The transmission modulators were always by them selfs, likely due the chance of it going bad and ****ing fluid up the line, this could then contaminate what ever else was plumbed to it. Same as the PCV and power brakes, you don't oil residue in the brake reservoir.
But, if all you have is one port, then that's how it needs to be. Distributors can be full vacuum or ported vacuum, it depends on how the engine idles, once moving down the road, it makes no difference.

 

Thank you
Terry aka dirt t

 

I don’t think a vacuum advance, or anything can be affected with transmission fluid if the modulator goes bad.
Anything connected on the line has vacuum applied to it, any device is not pulling a vacuum.
I think the engine will be taking all the fluid.
The signal you’re getting for anything on the line could be affected, I’m in agreement with that.

 

@Budget36 I agree that when running, fluid will be pulled straight from trans into intake. When shut off after, the hose or tube will have residue that could creep into the other hose or line, though. Depends on routing.

 

Normally I would agree with that. However, years ago I was working on an off topic Late 80s ford one time that the heater controls had quit working. It seems the modulator valve had been leaking for quite some time and trans. fluid did get into one of the vacuum motors for the heater and destroyed the diaphragm. I know there was a check valve in the system so I suppose when the engine was off it could create enough pull to get trans fluid into the system, It had to get there somehow.

Anyway, what I'm getting at is the hose routing should be direct and short enough to avoid a spot that could collect trans. fluid from pooling in the event of mod. valve failure. That should make for a trouble free system nearly forever.