c6 modulator valve

[sleeper bird]

iv got a 66 q code and was wondering where should be the vacuum source for the modulator valve,i believe its connected to the carburetor?Iv read several post that say it should be connected to the brake booster,but there is another hose connected to that and then runs to the tin can.Iv got the jim osborne assembly book but i dont think iv seen a vac diagram

[sleeper bird]

i did see the other post that said to connect to brake booster i just wanted to confirm the c6 was the same,also my car has the smog pump.

[sleeper bird]

also is there a manual that has the vac line diagram?iv got the osborne body and interior,and the electrical manual

[RedBird64]

The modulator needs to be connected to manifold vacuum. So you don't want to connect it to a reservoir or the timed port on a carb because the trans will get the wrong signal.

[sleeper bird]

Thanks for the reply

[sleeper bird]

just went outside and checked and the modulator is connected to the front of the carburetor,im going to correct this.Now i need to figure out what should be connected to the carb vac .There is a steel line that comes out of the side for the advance,and right next to it is another port im sure it should be doing something other than being capped off?Oh its an original autolite

[RedBird64]

One port is "timed" and only has vacuum when you advance the throttle past idle. This one goes to your vac. adv. If you put a vacuum gauge on it at idle, you wont see any vacuum.
The other port is manifold vac and has vacuum all the time. You could use that one to connect to the modulator and it would work fine but it wasn't plumbed that way from the factory. (You absolutely don't want a Ford vac. adv. hooked up to this one)

Scott

[sleeper bird]

the closer i look at it that port comes out of the carb spacer so i guess it was connected to manifold vacuum. So that port in the spacer was originally for the modulator valve?or should it be connected to something else?

[redstangbob]

Since this question is specifically about a 66, it's probably best not to confuse sleeper bird with info that might not pertain to his car. I suggest reviewing the photo documentation Jim has done on his 66. good luck, Bob C http://www.tbirdgarage.com/Site_2/66_Al ... lbums.html

[sleeper bird]

That helps alot thanks.

[RedBird64]

the closer i look at it that port comes out of the carb spacer so i guess it was connected to manifold vacuum. So that port in the spacer was originally for the modulator valve?or should it be connected to something else?

Being under the carb, it will be manifold vac. I suspect that connection originally went to the Dist. (not sure) but the connection would work equally well for the modulator if you just want a functionally correct spot to connect to.

Scott

[tbirdart5]

65 Bird has a cruise -o-matic transmission which has the transmission modular valve connected the brake booster.

the 66 Bird has a c-6 transmission. The modular vacuum hose is connect to the multi-port intake manifold tree

[sleeper bird]

in the pictures sent, the vac line for the c6 is connected to the vac port in the carb spacer in the front of the carb

[scumdog]

Just had a look at my '66, it has a COM and the modulator hose runs from a brass fitting on the rear of the manifold on the passenger side, There's another vacuum hoses there for the PCV hose from memory.

The brake booster has a plugged fitting on it that is the same dia. as would suit the vacuum hose for the modulator

[tbirdart5]

Sleeper:
Your 66 should have one vacuum port on brake booster valve.

Someone put a 65 booster on your car- which is OK. they fit and work the same but not factory original.

Is your car a California Car ? Pretty sure the vacuum port on carb spacer is part of the Calif. smog set-up.

Tbirdart