PontiacBonnevilleClub.com

Hi. I'm installing an engine on my Bonneville after repair. I have a question. How are vacuum lines connected to the trans through twin metal tubes ?
Please take a picture of an engine without a top cover from the throttle body side.

If it's your 98, there shouldn't be a vac line that goes to the trans. 97 was the last year for the vacuum modulated 4t60-e, your 98 should have a 4t65-e with electronic line pressure modulation.

Sorry, my mistake in indicating the car. That's right, 97.

Also, it should only be a single vacuum line going to the trans modulator.

Maybe you should post a picture of what you're working with and we can help you that way.

How to Post Pictures with Imgur - Step by Step Guidelines

For the dual line, one goes to the charcoal canister and one goes to the vacuum modulator on the front of the transmission.

Here's a pic from over 20 years ago of a cold air intake I made for my 95, also L36/4t60-e equipped. You can see the line going down to the transmission vacuum modulator then there's a line going forward from that area which goes to the charcoal canister.

I see from the diagram that one line goes to the charcoal canister past the service port, and the other to the transmission.
The bend in the tubes does not allow for normal direct connections. Maybe I oriented them incorrectly.

At first look, it seems like the double tube is upside down but it's hard to tell without being there.

I found this pic that might help:

[quote="95naSTA"]At first look, it seems like the double tube is upside down but it's hard to tell without being there.

I found this pic that might help:

Thank you for your help.
The tube seems to be installed correctly, but the upper edge to the EVAP is bent strangely. I will connect it with rubber hoses.