1970 Ls5 Vacume

[Jeff S.]

Can some one help me with the location of the vacume source for my headlights on a 1970 454 standard shift with power brakes and a/c Thankyou Jeff

[Joe L.]

Re: 1970 Ls5 Vacume

Can some one help me with the location of the vacume source for my headlights on a 1970 454 standard shift with power brakes and a/c Thankyou Jeff

Jeff------


Fitting on the intake manifold, a few inches behind the carburetor.

[Terry M.]

Re: 1970 Ls5 Vacume

Can some one help me with the location of the vacume source for my headlights on a 1970 454 standard shift with power brakes and a/c Thankyou Jeff

Jeff,

The entire vacuum system (headlamps, windshield wiper door and HVAC system) comes from the location Joe mentions. That is the same fitting that the vacuum to the power brake booster gets its vacuum from.

[Jeff S.]

Re: 1970 Ls5 Vacume

Thankyou for the good info. I guess the vacume advance then goes to one of the ports on the tcs. Thankyou Jeff

[Terry M.]

Re: 1970 Ls5 Vacume

Thankyou for the good info. I guess the vacume advance then goes to one of the ports on the tcs. Thankyou Jeff

Yes Jeff that is correct. There is a drawing of those connections in the Assembly Instruction Manual (AIM) for 11970. Click the radio button at the top of the page that is labeled "NCRS STORE" and look for the NCRS Library section. They will get a 1970 AIM right out to you.

[Jim T.]

Re: 1970 Ls5 Vacume

Thankyou for the good info. I guess the vacume advance then goes to one of the ports on the tcs. Thankyou Jeff

If your 1970 is a driver your driving pleasure will benefit if you bypass the tcs and connect your vacuum advance unit directly to a full time vacuum connection on the carb. Your engine will run cooler in stop and go traffic and your gas mileage will increase in city driving. My original owner 70's vacuum advance has not been controlled by the tcs since it was a month old. Direct full time vacuum increased my gas mileage and the engine ran cooler in Dallas, TX city traffic using the factory air conditioning during the hot summers.

[Jeff S.]

Re: 1970 Ls5 Vacume

Thanks for the info Jim, I am trying to get my car done to take it to the Florida regonal. but I do have one vacume line that comes from the firewall along with the black with green tracer and the black with white tracer, this line is just black and I do not know where it goes. the group of vacume lines come out of the firewall right next to the a/c harness,any clue?

Jeff

[Alan S.]

Re: 1970 Ls5 Vacume

Hi Jeff,
I'm not too familiar with the a/c system so I'm looking at the a/c section of the AIM that Terry mentioned.
I'm looking at UPC 60, Sheet E5; A/C- Vacuum Harness Diagram.
I see the 3 hoses, 1 black, 1 green stripe, and 1 white stripe. It appears the black hose travels along the face of the firewall.
I then looked at C60, Sheet E4; Front Vacuum Hoses & Wswa Reservoir. It appears the black hose connects to a small tee in the large yellow vacuum supply hose near the wiper door actuator.
Here's a picture of that connection on my 71 non a/c car.
I hope this helps you!
Regards,
Alan

The last picture shows the single hose of a non a/c car where I believe your 3 hoses enter the firewall.

[Jeff S.]

Re: 1970 Ls5 Vacume

Alan, thankyou for the great pictures ,that should be big help. Jeff