700r4 vacuum switch hose connection?

[83silverado400]

Hi, been checking out this site for awhile, and I must say I'm very impressed, lots of great info. Has been very helpful, as my son and myself have been working on his 83 silver ado, need help with the tcc lock up vacuum switch mounted by brake booster. We took out the original 305 with a rod problem and put in a 1977 400, with no air or any sort of polution stuff hooked up, we have the tv cable hooked up and adjusted, but where does the vacuum switch vacuum line get hooked up to.? Does it get a ported or manifold vacuum. One more question , those black plastic ball jobbies with vacuum lines attached to them, need to be hooked up to what fitting , engine, carb,? We are lost ,thanks for any input .

 

[Camar068]

Can't help you, but I'll agree with you on the wealth of info on here. I've learned so much every time the tax money comes in, one of the first things I do is donate because I've taken in way more info than I've given. LOL be nice to win the lottery and round 'em all up in one place.

Someone will chime in to help you out.

 

[1987 GMC Jimmy]

Hi, been checking out this site for awhile, and I must say I'm very impressed, lots of great info. Has been very helpful, as my son and myself have been working on his 83 silver ado, need help with the tcc lock up vacuum switch mounted by brake booster. We took out the original 305 with a rod problem and put in a 1977 400, with no air or any sort of polution stuff hooked up, we have the tv cable hooked up and adjusted, but where does the vacuum switch vacuum line get hooked up to.? Does it get a ported or manifold vacuum. One more question , those black plastic ball jobbies with vacuum lines attached to them, need to be hooked up to what fitting , engine, carb,? We are lost ,thanks for any input .

I'm attaching the vacuum diagram for your year. Basically, the line comes off the switch, there's an inline delay valve, which yours has, and it goes to a thermal valve switch (TVS), which has a line that goes to the carb. Simply pull the TVS from your old engine using this diagram. For the other concern, a line comes off the back of the intake between the carb and distributor, and a check valve that splits two ways comes after that. I just bought one of those check valves the other day so they're still common. One of those splits goes to the black vacuum storage canister you mentioned, and if you have cruise, you'll need a Y-shaped barb fitting right before the line gets to the canister that splits off to go the cruise servo. The other split at the check valve goes to the setting control vacuum line for the HVAC system. I can give you some pictorial aides Friday or Saturday if you still need them by then, but you should be able to track most of it down, especially if you don't have cruise control.

 

[83silverado400]

Thanks for info, should get us going in right direction

 

[83silverado400]

I guess I'm stilled confused with a vacuum line hook up point, my trucks engine is all stripped of a/c /airpump , no egr, the only vacuum lines needed should be for dist, pcv valve, brake booster, and a vacuum source for the tcc lockup.do I need to hook the vacuum hose coming from the switch (mounted by brake booster) to a port on my quadrajet or to direct manifold fitting in order for my lockout vacuum switch to work. Sorry for the dumbness on my part,

 

[HotRodPC]

Since you've bypassed all the smog devices, I doubt you're very concerned about being politically correct about where the vacuum comes from, so it can come from anywhere so long as it has vacuum. Ported just means there is no vacuum at idle and for lock up to function, you need to be moving down the highway in 3rd of 4th gear so you're not ideling therefore just go to a hot all the time vac source whether you T off the intake or come off the carb doesn't matter. All the TVS switch Jesse mentioned in his well laid out explanation is for, is to keep the lock up from happening before the engine warms up to optimal operating temperature, most likely another emissions device and the TCC probably likes warm transmission fluid too. Soooo, just hook up the vacuum to where ever you see fit.

As far as the vacuum storage ball aka vacuum amplifier, it too can hook up to any full vacuum source. The vacuum amplifier is necessary to operate all your blend doors in the air handler under the dash for Hot and Cold, and for blower air to be directed to the floor, bilevel or defrost, as well as pull offs so if you change the direction of the air with the engine running, like from defrost to floor, then you'll want your blend doors to operate properly even if you don't have the AC hooked up and functioning.

 

[83silverado400]

Thanks so much for the help guys, going to work on truck this weekend. I'm a marine/atv, motorcycle and snowmobile mechanic for the past 35 years, this car and truck stuff if kind of Greek to me, so bear with me for my questions, but if u have any powersports questions, feel free to ask.