Help identifying part

[tpep3]

I have these 2 metal tubes that terminate in rubber tubing running along the firewall. Looks like they go to the transmission but not sure what they are for or where to mount them on my new Holley Sniper and Edelbrock intake. I imagine they r vacuum lines??? Thx

 

[rguest3]

The C4 Transmission only has one vacuum line. Whats it look like on the other end of those lines? Do they merge together?

 

[Boss Hugg]

Those lines go to the modulator on the back of the VB area of the transmission. Most c4's had a single diaphram modulator I think. I bought a 2wd C4 the other day that has a dual diaphragm modulator and my bronco also had a dual also before I swapped the trans out.

 

[CopperRanger]

Like already said, vacuum lines going to the vacuum modulator on a C4 automatic. On my 74 one went to the stock 2 barrel spacer plate with a EGR valve and the other to the intake manifold

 

[Rustytruck]

My 1974 Bronco had dual transmission vacuum lines to the C-4 modulator. There was an end port and a side port on the modulator. It was a press in style green stripe modulator. Since your not running all the other emissions equipment on your offroad Bronco you could just run a single port modulator hooked to manifold vacuum.

 

[tpep3]

So can I use a T connector and merge them to one and then route to a vacuum port on the manifold? Or do I have to keep them separate if keeping both.

 

[Viperwolf1]

So can I use a T connector and merge them to one and then route to a vacuum port on the manifold? Or do I have to keep them separate if keeping both.

You can try that and see how it shifts. Maybe also try the rear port only and let the front port breath. A better solution is to just get a single port modulator. Only 73 and 74 with egr used the dual port modulator.

 

[Rustytruck]

Use manifold vacuum on the rear port the smaller side port leave open if you not using it but you have to plug the disconnected vacuum line or you will have a direct vacuum leak.