Removing Dash To Replace Vacuum Lines
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 828
Likes: 2
Removing Dash To Replace Vacuum Lines
Can I please get some tips on removing the dash on the passengers side and center console so I can replace all of the vacuum lines that I bought. I changed the back control on the heat/A/C-Defrost control but it did squat. I want to check all and change all lines so I can have a defrost, heat and a/c when I need it.
Thanks
Jack
1977 C3
Thanks
Jack
1977 C3
Burning Brakes
Joined: Dec 2004
Posts: 825
Likes: 0
From: Hanging out back with the dark horses. Wa.
Can I please get some tips on removing the dash on the passengers side and center console so I can replace all of the vacuum lines that I bought. I changed the back control on the heat/A/C-Defrost control but it did squat. I want to check all and change all lines so I can have a defrost, heat and a/c when I need it.
Thanks
Jack
1977 C3
Thanks
Jack
1977 C3
All those I have mentioned just have screws and are easy to remove.
Why are you replacing all the lines? Sounds like something is just unplugged
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,481
From: Southbound
Cruise-In II Veteran
The diagrams in the assembly instruction manual (AIM) will help. The AIM also has a page showing all the AC vac hose routing, color codes, and the function of each.
On your 77, remove the passenger's side kick panel; remove the console trim panels; remove the trim screws from the dash pad. Pad will come off, but go slowly. You are likely to find flasher and possibly a courtesy lamp attached to the rear of the panel.
On your 77, remove the passenger's side kick panel; remove the console trim panels; remove the trim screws from the dash pad. Pad will come off, but go slowly. You are likely to find flasher and possibly a courtesy lamp attached to the rear of the panel.
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 828
Likes: 2
I think all you would need to do is remove the clove box insert,Heater ducts, center guage cluster and maybe tunnel carpet. Not sure if you want to remove the dash.
All those I have mentioned just have screws and are easy to remove.
Why are you replacing all the lines? Sounds like something is just unplugged
All those I have mentioned just have screws and are easy to remove.
Why are you replacing all the lines? Sounds like something is just unplugged
I bought a vacuum line replacement kit a few months back. My 77 Vette is now going on 34 years old. That is enough life for any rubber vacuum hoses. Once I replace all of the lines and check each circuit, I will know which one is at fault and not have to do it again for another 34 years. I only hear a fan motor blowing with no control of where it is going. A defroster or a/c or heat when I want them would be nice.
Thanks
Jack
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
The most likely vacuum lines to get damaged from "old age" are the ones in the cowl/wiper tray area. These are exposed to sunlight and the elements. The hoses in the interior could wear out...but I've not heard of one doing so. They can become disconnected, however.
You shouldn't have to take the gauge cluster out. Removing the right-side dash pad and the upper plate on the tranny console should be all you need to do.
You shouldn't have to take the gauge cluster out. Removing the right-side dash pad and the upper plate on the tranny console should be all you need to do.
Instructor
Joined: Jun 2010
Posts: 199
Likes: 0
if you want to replace them all you need to remove the pass side dash and the gauge cluster to get to the def vacuum actuator and the port for the lines to the switch remove the HVAC ducting from the pass side and from behind the cluster as the rest of the vac lines run behind that and over the heater box also needs out of the way so you can get to the firewall gromit. the pass kick panel needs removed to get to the vent actuator. i just did all this on my 77 trying to figure out whats not working as i am having the same issues i have it narrowed down to the switch its leaking vac at the lil rubber maze that the 5 ports plug into.
as for the pass cluster the hazards are in a spring clip on the bottom of the panel the curtisy light is screwed to the ducting. pass side 5 screws it falls out take the gauge cluster out first as that always goes in last cuz the panels slip into a grove on the side of the gauge cluster.
happy hunting hope you get it figered out mine all work on hand vac pump its the switch that don't in mine.
as for the pass cluster the hazards are in a spring clip on the bottom of the panel the curtisy light is screwed to the ducting. pass side 5 screws it falls out take the gauge cluster out first as that always goes in last cuz the panels slip into a grove on the side of the gauge cluster.
happy hunting hope you get it figered out mine all work on hand vac pump its the switch that don't in mine.
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 828
Likes: 2
if you want to replace them all you need to remove the pass side dash and the gauge cluster to get to the def vacuum actuator and the port for the lines to the switch remove the HVAC ducting from the pass side and from behind the cluster as the rest of the vac lines run behind that and over the heater box also needs out of the way so you can get to the firewall gromit. the pass kick panel needs removed to get to the vent actuator. i just did all this on my 77 trying to figure out whats not working as i am having the same issues i have it narrowed down to the switch its leaking vac at the lil rubber maze that the 5 ports plug into.
as for the pass cluster the hazards are in a spring clip on the bottom of the panel the curtisy light is screwed to the ducting. pass side 5 screws it falls out take the gauge cluster out first as that always goes in last cuz the panels slip into a grove on the side of the gauge cluster.
happy hunting hope you get it figered out mine all work on hand vac pump its the switch that don't in mine.
as for the pass cluster the hazards are in a spring clip on the bottom of the panel the curtisy light is screwed to the ducting. pass side 5 screws it falls out take the gauge cluster out first as that always goes in last cuz the panels slip into a grove on the side of the gauge cluster.
happy hunting hope you get it figered out mine all work on hand vac pump its the switch that don't in mine.
Thanks
Jack
Racer
Joined: May 2007
Posts: 370
Likes: 0
From: Cherry Hill N.J.
one of the most likely broken lines is the plastic line that runs to the vacuum heater shut off valve in the engine compartment..
The valve is located on the heater core supply line..
The plastic line becomes brittle and probably has numerous cracks...
You can usually replace the plastic line as it comes OUT of the firewall with a small vacuum line to the valve.
THAT MIGHT SOLVE ALL YOUR HEATER CONTROL PROBLEMS...
Good Luck
The valve is located on the heater core supply line..
The plastic line becomes brittle and probably has numerous cracks...
You can usually replace the plastic line as it comes OUT of the firewall with a small vacuum line to the valve.
THAT MIGHT SOLVE ALL YOUR HEATER CONTROL PROBLEMS...
Good Luck
Last edited by BHRIG; Jul 16, 2010 at 09:15 PM.
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Instructor
Joined: Jun 2010
Posts: 199
Likes: 0
if you just want to test them for now you can see them all work without removing the dash cluster if you remove the pass side carpet along the tranny tunnel you can access the 5 ported plug and hand pump them sepertly. the def frost you can see move from the drivers floor board the pass vent can be seen from the kick panel and the outside cowl ventpush the mesh aside to see that one. the cowl vent and kick panel vent work together. and the main heaterbox door can be seen by looking under neith the pass floor boards and watch for the rod moving the goes threw the box to hold the door in.
like i siad i have done all this to find they all work to call corvette world to get the 1 out of 4 rubber mazes don't work lol not very good odds.
also was suggested to me ina earlier thread to place a lil bolt and nut threw where the silver spring and nylon rivet goes threw the middle of the rubber maze to snug it up as the nylon rivet does not hold alot of tension
like i siad i have done all this to find they all work to call corvette world to get the 1 out of 4 rubber mazes don't work lol not very good odds.
also was suggested to me ina earlier thread to place a lil bolt and nut threw where the silver spring and nylon rivet goes threw the middle of the rubber maze to snug it up as the nylon rivet does not hold alot of tension
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 828
Likes: 2
if you just want to test them for now you can see them all work without removing the dash cluster if you remove the pass side carpet along the tranny tunnel you can access the 5 ported plug and hand pump them sepertly. the def frost you can see move from the drivers floor board the pass vent can be seen from the kick panel and the outside cowl ventpush the mesh aside to see that one. the cowl vent and kick panel vent work together. and the main heaterbox door can be seen by looking under neith the pass floor boards and watch for the rod moving the goes threw the box to hold the door in.
like i siad i have done all this to find they all work to call corvette world to get the 1 out of 4 rubber mazes don't work lol not very good odds.
also was suggested to me ina earlier thread to place a lil bolt and nut threw where the silver spring and nylon rivet goes threw the middle of the rubber maze to snug it up as the nylon rivet does not hold alot of tension
like i siad i have done all this to find they all work to call corvette world to get the 1 out of 4 rubber mazes don't work lol not very good odds.
also was suggested to me ina earlier thread to place a lil bolt and nut threw where the silver spring and nylon rivet goes threw the middle of the rubber maze to snug it up as the nylon rivet does not hold alot of tension
Jack
77 C3
Melting Slicks
Joined: May 2002
Posts: 2,716
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
Just got mine working,
It was the hot coolant shut off valve leaking on mine.
I don't have the heater hooked up so I just capped the line going to the valve, every thing works now.
I just took a pair of needle noose pliers and pinched the lines one at a time until I found the one causing the problem.
I didn't have to remove the gauge cluster I just took it loose and was able to move it back enough to get the clearance I needed.
I did pull all the duct and actuators out that I could get out for cleaning and check their condition.
Neal
It was the hot coolant shut off valve leaking on mine.
I don't have the heater hooked up so I just capped the line going to the valve, every thing works now.
I just took a pair of needle noose pliers and pinched the lines one at a time until I found the one causing the problem.
I didn't have to remove the gauge cluster I just took it loose and was able to move it back enough to get the clearance I needed.
I did pull all the duct and actuators out that I could get out for cleaning and check their condition.
Neal
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 828
Likes: 2
The diagram/schematic for the vacuum shows only 4 lines from the switch rear control. I seem to have 5 lines from the firewall, I am a bit confused. The original capping plate has one blocked off. I have the new lines directly connected to the new black vacuum switch as the cap has smaller holes and the lines do not attach.
Jack
Intermediate
Joined: Feb 2010
Posts: 28
Likes: 0
I have the exact problem,the fan works but blows no air anywhere.As far as the people said about what line usually goes bad,this is not a good way to look at the problem.The old lines are much smaller than the new ones and all of the old lines should be replaced. I got the kit also and replaced all but 2 lines,one to the defroster and the other in the same area.Can't feel up inside far enough to get to the ends. I replaced as much as I could on these lines and spliced them as far as I can reach. Now it appears that these are the only 2 that are not working.I have an '82 with air and I am also wondering what is the easiest way to get to the end of these 2 lines.So if anyone can help,please do????
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 828
Likes: 2
On the 77 there are only 4 lines that come to the back of the control. The 5th is covered.
For some reason, I can't get the control to stop hissing in off. I also can't get the main vent to open in A/C mode (it does open with a mighty vac). The heat and defrost work fine. The lower cold-----Hot is fine. The upper and lower outer vents only opens with a mighty Vac, not with the switch.
Thanks
Jack
77 L-82
For some reason, I can't get the control to stop hissing in off. I also can't get the main vent to open in A/C mode (it does open with a mighty vac). The heat and defrost work fine. The lower cold-----Hot is fine. The upper and lower outer vents only opens with a mighty Vac, not with the switch.
Thanks
Jack
77 L-82
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Is the rotary control separating ? Pretty common problem.
edit- http://willcoxcorvette.com/product_i...ducts_id=12686
edit- http://willcoxcorvette.com/product_i...ducts_id=12686
Last edited by ...Roger...; Jul 6, 2012 at 06:40 PM.
Instructor
Joined: Oct 2008
Posts: 176
Likes: 1
When mine stopped it was because of the selector switch. If it turns out to be your issue be sure to buy the more expensive type. I bought a cheap oe style ended up replacing that one the next year, when they are cold and moved fast they break spring goes flying your back at square one.
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 828
Likes: 2
Is the rotary control separating ? Pretty common problem.
edit- http://willcoxcorvette.com/product_i...ducts_id=12686
edit- http://willcoxcorvette.com/product_i...ducts_id=12686
The are both the same. I put grease around all possible spots that can leak. (T old me to)
They are just 2 pieces of plastic held together with a plastic pin.
Thanks
Jack
77 L-82
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 828
Likes: 2
When mine stopped it was because of the selector switch. If it turns out to be your issue be sure to buy the more expensive type. I bought a cheap oe style ended up replacing that one the next year, when they are cold and moved fast they break spring goes flying your back at square one.
Do you have a picture of the part?
Thanks
Jack
