96 LeSabre AC Losing Vaccume - Electric?

I have a 96 LeSabre that loses AC through the vents. If the temperature is mild outside, there seems to be no issue, but if it's the least bit warm, or if I've been driving 5 minutes or so, you hear a soft noise like a damper closing and the AC no longer blows through the normal vents. It blows out somewhere, probably the defrost vents. This has been happening for over 5 years. I really don't want to spend another hot summer in Texas!

I've taken the car to mechanics twice, and twice they were unable to fix the issue. Unfortunately, both businesses went under before I could take the car back and ask them to try again.

I've read quite a few postings on this forum that described this issue and they said when you're losing pressure like this (intermittently) it sounds like a hose leak. In those postings, it said to look for a hose located in an odd-shaped plastic box on the firewall near the master cylinder. I can't find that box. My husband and I have both looked and see nothing. We don't see the box, and we don't see any hoses going to or coming from the AC.

My husband read elsewhere that instead of a vaccume, the AC may be electric. Any truth to that, and can anyone tell me what that means and what we look for? We've gone to the library and searched the Chilton and Haynes manuals and can find nothing. What do we do now? Any help would be greatly appreciated.

Thank you!

I have a 96 LeSabre that loses AC through the vents. If the temperature is mild outside, there seems to be no issue, but if it's the least bit warm, or if I've been driving 5 minutes or so, you hear a soft noise like a damper closing and the AC no longer blows through the normal vents. It blows out somewhere, probably the defrost vents. This has been happening for over 5 years. I really don't want to spend another hot summer in Texas!

I've taken the car to mechanics twice, and twice they were unable to fix the issue. Unfortunately, both businesses went under before I could take the car back and ask them to try again.

I've read quite a few postings on this forum that described this issue and they said when you're losing pressure like this (intermittently) it sounds like a hose leak. In those postings, it said to look for a hose located in an odd-shaped plastic box on the firewall near the master cylinder. I can't find that box. My husband and I have both looked and see nothing. We don't see the box, and we don't see any hoses going to or coming from the AC.

My husband read elsewhere that instead of a vaccume, the AC may be electric. Any truth to that, and can anyone tell me what that means and what we look for? We've gone to the library and searched the Chilton and Haynes manuals and can find nothing. What do we do now? Any help would be greatly appreciated.

Thank you!

Hello and welcome to AFs!

Sorry to hear that you are having trouble with your LeSabre. I have a 97. Do you have manual controls on your heater/AC or automatic? I'll try to find my manual (just reciently moved and don't know where everything is) and do some looking for you. Also, the two shops that you took it to, what did they do? What parts did they replace?

Regards

Dan

I have a 96 LeSabre that loses AC through the vents. If the temperature is mild outside, there seems to be no issue, but if it's the least bit warm, or if I've been driving 5 minutes or so, you hear a soft noise like a damper closing and the AC no longer blows through the normal vents. It blows out somewhere, probably the defrost vents. This has been happening for over 5 years. I really don't want to spend another hot summer in Texas!

My husband read elsewhere that instead of a vaccume, the AC may be electric.
Thank you!

Let me see if I can help. I have a 98 LeSabre that developed the loss of vacuum to the one vacuum motor that moves the door inside the box and makes the air come out of the dash instead of going up to the defroster openings.

When it does lose the control and air won't come out the dash vents, let's test to see if you have any control of the doors using the vacuum. Put the settings on heater. See if you have air coming out the defrost--put the motor speed on high so that you can feel the air with your hand at the windshield and at the heater openings on the floor.

If you can push different buttons and make the air change where it comes out, then you still have vacuum to the controls inside. This should work as a test whether or not you have manual air of the dual auto air system with digital temperature readout. But let us know in your next post which you have.

If you can't control anything, then you may be losing vacuum to the interior. There could be an opening in a hose under the engine compartment or a cracked reservoir-which is a plastic bottlelike thing. On my 93 it was on the firewall and was part of the MaxiCenter Relay and fuse center-it was right next to the big round brake booster vacuum unit. There was a hose going into it from the motor and that sometimes got pulled loose. It was about a 1/4 inch diameter rubber hose.

On my 98 the container for storing some vacuum is under the right front fender in front of the wheel. I have to lie on the ground to see it. Right after I had the motor running I pulled off the black plastic hose going to it and got a whoosh meaning air was rushing in. If I didn't get the whoosh, that could mean I have a vacuum leak which could be a hose burned through or a crack in that bottle in front of the wheel.

If you have good vacuum with 20 seconds of turning off the motor, then your AC problem may be the soft plastic connector inside the car which carries vacuum in little 1/8 inch diameter lines from your controller (programmer) to the proper vacuum motors on the heater housing up above the driver's right foot.

The rubbery connector has thin black nipples on the opposite part of the connector when put together and those soften and pull closed with vacuum and block the vacuum. I can post a picture when you need to see what you're looking for. It's on the corner of the heater box under the dash. You have to take off the plastic panel above the passenger's feet (hush panel) that quiets sound from motor and heater, and it helps to take off the glovebox door, which is 5 or 6 screws along bottom of dash on glovebox door.

The AC and heater is controlled by the vacuum and your connection to that control box (programmer) is by electrical connections from the dash buttons you push. If that doesn't work right you get no lights, switches don't change lights, flashing lights... etc.

I replied to both your posts, but it seems it got lost. I must have messed up.

To answer your questions...

The AC is manual.

When the AC lost vacuum today, I put on the heat. It blew from the bottom vents, but not the ones the front vents (the ones that hit your face). My husband doesn't think heat is supposed to come out of those vents ever, but I'm not sure I agree with that...hmmm.

We didn't have a chance to crawl under the car and look for a hose under the wheel cover, but we will today (Sunday), if I can talk my husband into it.

It would help if you have a picture to post of where the hose is supposed to be. You wouldn't happen to have a picture of the box on the firewall by the Master Cylinder that's supposed to house the AC vacuum hose? Maybe if we saw a picture we'd realize what we should have been looking at (for).

Thanks so much for your replies.

I replied to both your posts, but it seems it got lost. I must have messed up.

To answer your questions...

The AC is manual.

When the AC lost vacuum today, I put on the heat. It blew from the bottom vents, but not the ones the front vents (the ones that hit your face). My husband doesn't think heat is supposed to come out of those vents ever, but I'm not sure I agree with that...hmmm.

We didn't have a chance to crawl under the car and look for a hose under the wheel cover, but we will today (Sunday), if I can talk my husband into it.

It would help if you have a picture to post of where the hose is supposed to be. You wouldn't happen to have a picture of the box on the firewall by the Master Cylinder that's supposed to house the AC vacuum hose? Maybe if we saw a picture we'd realize what we should have been looking at (for).

Thanks so much for your replies.

I don't have time right now to look in manuals but bilevel should givve heat out of the dash vents and floor vents--or cold, depending on where you have the temperature level set.

If you are able to get your heat to come out the bottom vents pushing the heat button and almost no air comes out the defroster openings then you have vacuum to the interior of the car. Note, on heat there is a smal amount of air bleed to the windshield to help keep it clear in cold or humidity for safety.

I'll post pictures of the interior part that's probably needing fixed later this evening when I get back from the ball game.

There was a posting recently about slowing of the A/C when accelerating. That talks about a vacuum leak. I too have that problem but it is in a 97 Le Sabre. Trying to find a method of fixing it. I know that it is a vaccum leak. Thing is to find it. Sounds like that posting shows a good area to start looking. I am.
v/r:smooch: