[hvac] vacuum leak in only two settings
03-02-2011, 04:00 AM
#1
Rennlist Member
Thread Starter
[hvac] vacuum leak in only two settings
Hi,
my system holds vacuum except for these two settings, what does that tell me? Which actuator do those settings relate to?
my system holds vacuum except for these two settings, what does that tell me? Which actuator do those settings relate to?
03-02-2011, 09:21 AM
#3
Rennlist Member
Rennlist Site Sponsor
Fairly easy to test them all...
Remove the small console panel by your right knee. Find the bundle of colored plastic tubes. You can follow them forward to the vacuum solenoids and pull the tubes off there one at a time and see if they hold vacuum. If that turns out to be difficult (access/removal of the rack of solenoids) you can get some small plastic or rubber tubing to use as splices and carefully cut the tubes one at a time and see if the end going up into the dash holds vacuum. If it does, splice it back. If not, plug the end going to the solenoid - no need to plug the upper end. Then when you get around to replacing the actuator, just splice the tube back.
Don't test the black one - that is supply. The orange one is the comb flap in the center outlet, which is the most common failure for some reason.
Repeat on the yellow (footwell), green (defrost) and blue (recirculate/inlet) lines.
The white line feeds the heater valve - you don't want to just plug it, you want to have the heater valve working. If the white line doesn't hold vacuum, remove the air cleaner housing and check the heater valve. If it doesn't hold vacuum, replace it. The black side goes toward the block.
The blue line to the recirculate/inlet flap is another critical device. If this actuator is bad, you can't shut off the air flow, and you get no recirculate on the air conditioning. Before you pull the blower motor to replace this actuator, check from below (over the passenger's feet) to make sure that the flap isn't just sticking. Just push up on the flap thru the grid.
Remove the small console panel by your right knee. Find the bundle of colored plastic tubes. You can follow them forward to the vacuum solenoids and pull the tubes off there one at a time and see if they hold vacuum. If that turns out to be difficult (access/removal of the rack of solenoids) you can get some small plastic or rubber tubing to use as splices and carefully cut the tubes one at a time and see if the end going up into the dash holds vacuum. If it does, splice it back. If not, plug the end going to the solenoid - no need to plug the upper end. Then when you get around to replacing the actuator, just splice the tube back.
Don't test the black one - that is supply. The orange one is the comb flap in the center outlet, which is the most common failure for some reason.
Repeat on the yellow (footwell), green (defrost) and blue (recirculate/inlet) lines.
The white line feeds the heater valve - you don't want to just plug it, you want to have the heater valve working. If the white line doesn't hold vacuum, remove the air cleaner housing and check the heater valve. If it doesn't hold vacuum, replace it. The black side goes toward the block.
The blue line to the recirculate/inlet flap is another critical device. If this actuator is bad, you can't shut off the air flow, and you get no recirculate on the air conditioning. Before you pull the blower motor to replace this actuator, check from below (over the passenger's feet) to make sure that the flap isn't just sticking. Just push up on the flap thru the grid.
