Need help with vacuum lines for AC to work for 67 Eldorado

[LtDan560]

I now have my heat working on my 67 Eldorado & I was able to get the parking brake off by shifting into Drive. I have been looking at the schematic & it has helped greatly. I cannot get the thermostat to work. When going from off to low, auto or high, it starts out at the dash vents & as soon as it warms up (10 seconds) it goes to the floor. The thermostat does not change anything. If I switch to vent then the hot air stops & I get cool air but I think it is just outside air.
The compressor runs on low, auto, high, fog & ice. Is that normal?
What is the 12 inch box behind the drivers headlight? Is that vacuum storage? I have a hose coming from the top right corner of it & it is not connected & appears to have no suction. Do you know where that hose goes? My schematic does not show the box.
Another question, does it matter where the hoses go on the master on-off switch? Is it just one big vacuum where all the hoses suck on one cavity?
I am sending this to 3 forums & an expert & hopefully some answers. Its taken a long time but I certainly have had progress.
Thanks
Dan

[www.eldorado-seville.com]

Hi Dan,
your symptoms are typical for a vacuum leak somewhere in the system. I'm pretty sure that your rotary valves would need some work. You can either refurbish them by yourself or get some new ones (very expensive NOS) from Classic Auto Air. I once had the very same problem as you describe. http://www.eldorado-seville.com/files/67acfix.php

If I switch to vent then the hot air stops & I get cool air but I think it is just outside air.

yes - if you switch to the vent position only outside air is drawn in - its neither heated nor cooled

The compressor runs on low, auto, high, fog & ice. Is that normal?

Yes that's how it should work - its always on - its only turned off in the vent position and off. At very low outside air temperatures it will also turn itself off.

What is the 12 inch box behind the drivers headlight? Is that vacuum storage? I have a hose coming from the top right corner of it & it is not connected & appears to have no suction. Do you know where that hose goes? My schematic does not show the box.

Yes that's the vacuum storage tank for the headlight doors.
There is a hose coming out of it. It should have a yellow stripe on it. Its a pretty important hose - its connected to the other storage tank and also goes to the headlight switch. Do the headlight doors work on your car?
I've snapped a quick picture with my mobile phone from the shop manual - I hope its readable -its not the best camera... on these pictures you can see the hose routing. Its too complicated to explain how it is connected. I've sent it to your email address.
If the 2 pictures are not readable I can scan the diagrams if you do not have a shop manual - but it could take some time as my scanner is not working right now.

Another question, does it matter where the hoses go on the master on-off switch? Is it just one big vacuum where all the hoses suck on one cavity?

Its does not matter how you connect them - one of the four ports of the master vacuum switch is not connected  on the Eldorado and plugged off.

Good luck!

[LtDan560]

Hi Gerald
Thanks again for your guidance. I will check this all out. The headlight doors have to be lifted sometimes. Any idea where to get a shop manual like yours. I bought 2 Chiltons repair books & they were terrible. A few simple procedures from the book were totally wrong like removing a radio!! Is the book made by GM? Do you know where to buy it? What is the approximate cost so I don't get ripped off?
Thanks again
Dan

[www.eldorado-seville.com]

Dan,
the original shop manuals were issued from Cadillac to Cadillac Dealers. These are the official manuals. Chilton manuals are not really good.
You can still find original shop manuals at various sources like here:
http://www.faxonautoliterature.com/1967-Cadillac-Repair-Shop-Manual-Original-P15083.aspx

There are also reprints available which are cheaper - but often especially the photographs did not reproduce very well.
http://www.faxonautoliterature.com/1967-Cadillac-Repair-Shop-Manual-Reprint-Calais-De-Ville-Fleetwood-Eldorado-P10845.aspx
I always recommend getting an original print.

You can also find shop manuals on CD-Rom: http://www.faxonautoliterature.com/1967-Cadillac-Repair-Shop-Manual-Body-Manual-on-CD-ROM-P19181.aspx

Shop manuals are not that expensive and you should get yourself a copy. They are an invaluable help when troubleshooting your Eldorado!

[LtDan560]

I just bought an original from the website like you suggested
Thanks
Dan

[LtDan560]

Today I hooked up the yellow stripe vacuum line from the front storage tank to rear tank & tried the lights. They went down fine but still work intermittent on raising. I have oiled some parts but may need to do more.
I hooked up another hose to the AC/heater vacuum motor & air blew from the dash vents.
I then put the regular hose back on & used small hoses to manually put the power servo in AC mode and air blew out of dash vents.
The thermostat does not seem to work in the manually set AC mode or when everything is hooked up properly & heat is at the floor. No temperature change is noted.
How do I test the thermostat?
The AC may need freon because it could just be outside air I am feeling. Its hard to tell because the temperature outside is 45 to 50 degrees Fahrenheit.
I can't wait till I get the shop manual!
This AC/heater problem has taken a long time & is frustrating so I do something else at the same time. I just completed the trunk today & it looks great.
Thanks again
Dan

["Cadillac Kid" Greg Surfas 15364]

Dan,
The factory service manual (especially in 1967) was written so that the average shop mechanic could successfully diagnose AC issues.  There are matrices and step by step diagnosis procedures for finding the problems.  There are essentially four separate and individual "systems" in your '67s air conditioning.
1. The air delivery system, including the fan and the ducts and dampers. 2. The heating system consisting of the heater core, the hot water valve, and the interconnecting hoses.  3. The coolling/dehumidification system consisting of the compressor and all the refrigeration components. 4 The control system which "ties" the first three systems together to perform as desired.  The service manual will help you decide exactly which system(s) are the source of your problems and suggest corrections.
Greg Surfas

[www.eldorado-seville.com]

Today I hooked up the yellow stripe vacuum line from the front storage tank to rear tank & tried the lights. They went down fine but still work intermittent on raising. I have oiled some parts but may need to do more.

There are some T-connectors along the line which also act as valves - make sure they are clean and freely working.
Check my website on how I made mine work again:
http://www.eldorado-seville.com/files/67eldoheadlightactuators.php

I hooked up another hose to the AC/heater vacuum motor & air blew from the dash vents.
I then put the regular hose back on & used small hoses to manually put the power servo in AC mode and air blew out of dash vents.
The thermostat does not seem to work in the manually set AC mode or when everything is hooked up properly & heat is at the floor. No temperature change is noted.
How do I test the thermostat?

I'm pretty sure that you have a problem in the rotary valve of the power servo... To check the temperature rheostat you will have to follow the troubleshooting guide in the shop manual...

The AC may need freon because it could just be outside air I am feeling. Its hard to tell because the temperature outside is 45 to 50 degrees Fahrenheit.

Make sure that you have enough freon in your system - otherwise you will ruin the compressor! Do any parts along the refrigerator hoses get cold? Is the temperature door freely moving?

I can't wait till I get the shop manual!
This AC/heater problem has taken a long time & is frustrating so I do something else at the same time. I just completed the trunk today & it looks great.

Even with the shop manual it will still be a pain to diagnose ;-)) but it will be very rewarding once you have it working again ;-)
Any pics?

[LtDan560]

Greg, thanks for your response, I hope to get the service manual in a few days.
Gerald, I will check the t-connectors & spray some silicone spray in the inlet. I hope it is that easy.
I will check the temperature rheostat when the shop manual comes in.
I am bringing it to a shop to check the freon & see what type it is & check the compressor.
The pipes closest to the compressor are slightly warm & pipes close to the firewall are slightly cold.
I think the temperature door is moving freely because when I switch to vent it cools down fast.
After the shop checks it out & if it still has problems I will resurface the rotary valves