Vacuum line hookup for 700r4 lockup harness

[94.Sierra]

I'm in the final stages of hooking my lock-up harness for my 700r4. It controls lock-up by vacuum and I wanna know a good spot to hookup this vacuum line that goes to the trans. Truck is a 94 with a 4.3 out of a 91

 

[chevy_man]

Is this something aftermarket that you're trying to add onto your existing transmission?


If you need vacuum there are several un-used ports in the throttle body IIRC.

 

[94.Sierra]

Yea it's a aftermarket lockup harness for the 700r4 that locks up the TC by vacuum pressure. I didn't have the harness and computer that came with the 91 to put in my 94 so I had to use a lockup harness. I'll have to check but I thought all the vacuum ports had something going to them after I hooked up the engine.

 

[chevy_man]

You could get the diesel lock-up valve setup from one behind a 6.2. Mine actually has one because it was built for a 6.2 blazer and I scored it for super cheap. It's also kinda nice knowing there are no electronics in it. My connector is only plugged in to keep it clean.


I'd just grab a T fitting and plug it in-line with any vacuum line off the manifold.

 

[94.Sierra]

I picked up a T fitting, I just didn't know if there were any vacuum lines I should stay away from. Thanks for the help man

 

[JonZ71]

the booster hose would prolly be the best place

 

[94.Sierra]

the booster hose would prolly be the best place

Thought of that too, but will that diminish braking any?

 

[JonZ71]

Shouldn't its all vaccumn pressure.

 

[94.Sierra]

I hooked in into the booster hose and it works great no leaking of air and locks up the TC just like it should. Thanks guys