Vaccum source for heat/ac control.

[Nodnarb76]

Starting to wrap up my LQ4 swap, and one of the last small details I have overlooked is where to attach the very small hose for my heater/ac control?
This hose is really small and I'm not sure what to hook it to.
Heard there may be a tab on the stock intake I can remove and use.

[First c10]

I put a tee in the brake booster line at the back of the intake and ran it to the stock AC ball canister then inside to the heater/AC control

[ls1nova71]

If you are using a truck intake, then there is a little tab you break off for a vacuum source. There are pics in my build thread, post 204. http://ls1tech.com/forums/conversion...c-10-a-11.html

[foamypirate]

Originally Posted by ls1nova71

If you are using a truck intake, then there is a little tab you break off for a vacuum source. There are pics in my build thread, post 204. http://ls1tech.com/forums/conversion...c-10-a-11.html

What this guy said. Passenger side of the intake towards the rear.

[First c10]

It made me a little nervous to brake that off. If it brakes flush your screwed. Time for new intake. But that is a perfect place to attached that vacuum line.

[Nodnarb76]

Originally Posted by First c10

It made me a little nervous to brake that off. If it brakes flush your screwed. Time for new intake. But that is a perfect place to attached that vacuum line.

Could I just cut off the tab to make sure it doesn't break off flush?
Also my climate control vacuum hose is really small. I'm worried it won't fit on that nipple.

[First c10]

Originally Posted by Nodnarb76

Could I just cut off the tab to make sure it doesn't break off flush?
Also my climate control vacuum hose is really small. I'm worried it won't fit on that nipple.

don't see why not!

[Nodnarb76]

Here is the really small hose I'm talking about. Anyone know what size this is?

[First c10]

I just ran a new vacuum hose from the ball/vacuum canister to my vacuum source. I think I used 3/16"

Is the hose in the picture hard tubing? Or soft rubber? And where does the other end go?

[foamypirate]

Originally Posted by Nodnarb76

Here is the really small hose I'm talking about. Anyone know what size this is?

Looks like the soft rubber end has broken off of your vacuum tubing (not hose). That should feed into the cab through a grommet on the passenger side of the firewall. You can get all sorts of vacuum tubing elbows and splices at the auto parts store to repair it, usually in the HELP! section. You should have a vacuum hose from the port on the intake, into a check valve, and then the check valve has two outputs, one for that vacuum tube, and one to the vacuum ball.

[Nodnarb76]

Originally Posted by foamypirate

Looks like the soft rubber end has broken off of your vacuum tubing (not hose). That should feed into the cab through a grommet on the passenger side of the firewall. You can get all sorts of vacuum tubing elbows and splices at the auto parts store to repair it, usually in the HELP! section. You should have a vacuum hose from the port on the intake, into a check valve, and then the check valve has two outputs, one for that vacuum tube, and one to the vacuum ball.

Hmmm, Sounds like I may have taken off more than I needed to when I pulled the motor out. Good news is I know exactly where the vaccum ball is. but have no idea where the check valve went.

[foamypirate]

Originally Posted by Nodnarb76

Hmmm, Sounds like I may have taken off more than I needed to when I pulled the motor out. Good news is I know exactly where the vaccum ball is. but have no idea where the check valve went.

The check valves are available in the HELP! section of most parts store, so no sweat there. They are only a couple bucks.

[First c10]

Originally Posted by foamypirate

The check valves are available in the HELP! section of most parts store, so no sweat there. They are only a couple bucks.

Check valve? Ok I am not sure I have one. What is the reason for a check valve on the vacuum line to the AC system?

[foamypirate]

Originally Posted by First c10

Check valve? Ok I am not sure I have one. What is the reason for a check valve on the vacuum line to the AC system?

The check valve, along with the vacuum ball, maintain vacuum for the climate control when the engine is under load (no manifold vacuum). In a nutshell, it keeps the control doors from going crazy when you mash the throttle.

[First c10]

Originally Posted by foamypirate

The check valve, along with the vacuum ball, maintain vacuum for the climate control when the engine is under load (no manifold vacuum). In a nutshell, it keeps the control doors from going crazy when you mash the throttle.

Ok I got that. I thought it was already in the ball? I haven't noticed any problems but maybe that's because I have a stock lc9 motor.