how to take apart vacuum lilne connections

[rcweston]

The heater and ac system on the 98 Lumina are defaulting to the defrost and floor mode. Only when driving on a perfectly level road or during deceleration will the vents work when the system is set to vent.
Reading through the post, it seems that I have a vacuum leak some where.
I have found the start of the vacuum line on the back side of the engine on the passengers side of the car. It traces to the drivers side by the break system then tees off to the front of the car and to the fire wall. I think the front line goes to the vacuum reservoir and the line that goes to the fire wall enters the cabin and supplies vacuum for the heater controls.
These lines are very hard and appear brittle. The rubber connections are very tight. How do they come apart without breaking them ? or are they glued together?
I have a hand vacuum pump that i would like to test them with, but I am applying a lot of force and believe they will break with more force. I just can't get them apart.
Does anyone have experience with these lines?
Thanks Rex

[jeffcoslacker]

I usually spray them good with WD-40 and let em sit a while, then push/pull/twist gently and they will come loose as that works under the connector.

Could probably save you some time though....typically when this happens the vacuum ball in the driver's side fender is broken, and you'll find it laying in there loose if you take some screws out of the inner fender liner in front of the tire so you can see up in there.

Usually it's that, or someone set the battery down on the vac line going to it and it finally broke. It runs right by there and tends to get in the way and get pinched or squashed when the battery is serviced....anyway I'd bet money you find the problem in that area....

[rcweston]

Your obviously someone that has a little experience in this area!
Thanks for the good info. I have broken plastic lines and connectors in the past trying to get them to twist and pull apart. using the wd-40 is a good tip in helping out.
As for the vacuum leak, I had previously taken the front fender apart to look at the vacuum ball, but didn't see anything out of the ordinary. This is why I was going to put a vacuum down each line from the tee in the line.
Sure enough, all the lines held a vacuum except the line going to the reservoir ball. A little more searching and I found the line with a break right in the battery area where it is concealed and hidden under lots of item, just as you stated.
I'll get it repaired next week and it should be working fine then.
Thanks again for your help.
Rex

[Tech II]

Some times these lines use a vac check valve, to retain the vac in the reservoir during hard acceleration.....might be worth checking also.....

As for removing the lines for plastic fittings(which might break if pulled/twisted too hard), I usually cut a slit with a knife to get them off and just replace lines with a roll of vac line, cut to any length needed....