98 Bonneville SE A/C only Blows cold on driver side ?

[SPLLOUDER]

Help . A/c blows real cold out of two driver side vents and floor vent . but warm-air Thur both passenger side vents and floor vent ?

Also, when car is say climbing a hill under load in a tall gear the force of all vents almost stops , and when i crest the hill at the top it will just start blowing again at full force .

This has to be a vacuum leak , but i have no where to start looking ? where should i start ?

[91NinetyEight]

The airflow is more than likely moving to the windshield vents under load, this is caused by a loss of vacuum. Check the vacuum tank (under the pass. fender on the 96-99, not sure about 00+) for cracks and make sure the fitting is on securely. If the tank is fine, you should check the entire length of that vacuum line, as well as the vacuum connection to the AC programmer under the dash for leaks.

If the passenger vents are blowing warm even though the passenger control is set to full cool, the problem sounds like the passenger air mix actuator. You do have dual zone climate control, right?

[SPLLOUDER]

The airflow is more than likely moving to the windshield vents under load, this is caused by a loss of vacuum. Check the vacuum tank (under the pass. fender on the 96-99, not sure about 00+) for cracks and make sure the fitting is on securely. If the tank is fine, you should check the entire length of that vacuum line, as well as the vacuum connection to the AC programmer under the dash for leaks.

If the passenger vents are blowing warm even though the passenger control is set to full cool, the problem sounds like the passenger air mix actuator. You do have dual zone climate control, right?

Thanks i will check .

yes this is for a 1998 Bonneville SE so all Manuel controls basic AC. so check for like a tank in the pass. fender well ? where exactly is it ?

[91NinetyEight]

If you look up under the pass. fender, you'll see a black tank with a vacuum line attached. It's directly under the battery tray, and accessible from under the car.

[imidazol97]

A/c blows real cold out of two driver side vents and floor vent . but warm-air Thur both passenger side vents and floor vent ?

I would suspect a misadjusted actuator for the passenger side blend door, but in a later post you said it was the manual control AC which only has one temperature blend door. So the next choice would be a freon level that is low.

Also, when car is say climbing a hill under load in a tall gear the force of all vents almost stops , and when i crest the hill at the top it will just start blowing again at full force .

It might be a vacuum leak at the reservoir tank or at the rubber connectors at the upper intake manifold for the line that goes inside the car. That rubber is in a very hot area and ages and cracks.

But another thing to check is a one-way valve that is under the relay center cover on the firewall. Take that off and look between the accumulator for the AC and the passenger fender behind the strut tower. There will be a bundle of electrical wires with a black vacuum hose that comes from the upper intake manifold. There is a check valve that does not let air go toward the heater and reservoir tank side when the throttle is opened dropping vacuum. Careully pull it off, the rubber will be old and easily torn. Try sucking on it one way and then the other. It should seal up when air is pulled toward the heater side. I've read of a couple of those not sealing. because of age.

Good luck

[SPLLOUDER]

A/c blows real cold out of two driver side vents and floor vent . but warm-air Thur both passenger side vents and floor vent ?

I would suspect a misadjusted actuator for the passenger side blend door, but in a later post you said it was the manual control AC which only has one temperature blend door. So the next choice would be a freon level that is low.

Also, when car is say climbing a hill under load in a tall gear the force of all vents almost stops , and when i crest the hill at the top it will just start blowing again at full force .

It might be a vacuum leak at the reservoir tank or at the rubber connectors at the upper intake manifold for the line that goes inside the car. That rubber is in a very hot area and ages and cracks.

But another thing to check is a one-way valve that is under the relay center cover on the firewall. Take that off and look between the accumulator for the AC and the passenger fender behind the strut tower. There will be a bundle of electrical wires with a black vacuum hose that comes from the upper intake manifold. There is a check valve that does not let air go toward the heater and reservoir tank side when the throttle is opened dropping vacuum. Careully pull it off, the rubber will be old and easily torn. Try sucking on it one way and then the other. It should seal up when air is pulled toward the heater side. I've read of a couple of those not sealing. because of age.

Good luck

first place i looked was under relay cover and the one way valves hoses where old and fell apart when i touched them . i replaced the hose from the plastic side to the valve . where does the littler hose travel too ? the fendor and ball resivor ? if so where is this reservoir ? is it behind the inner fender well on the front side ? i betcha all the hose are shoot .

thanks

[SPLLOUDER]

ok i slid under the front bumper under where the battery was and saw the black reservoir . there was a obvious small black hard plastic line going to the front of this reservoir . with a 90 deg fitting . it was completely broken ...

i bought some same 1/8 ruber tubing and surprisely it worked on both sides and is very snug and it fixed that break as well .



BUT .... Still not better ?


i only saw one connection to this reservoir where is the other connection where else should i look ?

[imidazol97]

i only saw one connection to this reservoir where is the other connection where else should i look ?

The hose from the reservoir goes to the T connections that's on the passenger side of the one-way valve. The other end of the T goes to the interior and the base of the T goes to the one-way valve and to the engine. Did you check the rubber at the engine connection. The hard plastic tubing doesn't deteriorate, that I know of. It's the rubber tubes used to join to other parts that breaks down.

If your reservoir tank line was wide open, and you have now sealed it with plain rubber, you should be getting lots more vacuum to the interior.

[SPLLOUDER]

Is there a diagram for these vacuum lines ? i found everything besides the T-Valve and where it connects to the engine ?

[SPLLOUDER]

Is there a diagram for these vacuum lines ? i found everything besides the T-Valve and where it connects to the engine ?

[imidazol97]

Is there a diagram for these vacuum lines ? i found everything besides the T-Valve and where it connects to the engine ?

Are you saying you can't find the T and the one-way valve?

[SPLLOUDER]

yes where is the T . I found the one way valve