Hose diagrams, vacuum, heater, window washer , and engine cooling

[gary griffin]

  I am in the final assembly stages of restoring my 1942  6719 and find only fragmented information on these items. I would love to have decent diagrams for the following for my 1942 which I hope is the same as all 1940's Cadillacs.

Heater hose diagram and actual hose locations.

Vacuum for wipers, antenna, radio, and heater system with under seat heaters.

In the old forum we could type in an item and see all of the previous posts but the new forum does not seem to have that feature.

I found  the vacuum diagram in the authenticity manual but it is incomplete and not showing routing but I could get by with it if I can not find out a little more information.

[Bill Ingler #7799]

Hi Gary; I think I can help you with most everything you need but in several postings. This is how it is set up on my 47 and I hope it is the same for the 42. Starting with the vacuum hose routing after coming through the firewall to under the dash. The first picture below is the vacuum hose that is attached to the end of the metal vacuum line which comes through the firewall. The rubber vacuum line now goes straight up the firewall blanket to almost the top of the dash. Now look at picture 2. At the bottom of the picture is a T fitting. The bottom of the T is the vacuum hose from picture 1. The vacuum hose from the right side of the T goes to the middle port of 3 vacuum  ports on the upper right side of the radio. The other two of those three ports accept the two rubber vacuum lines which go to the ports on the vacuum antenna. Now the left rubber vacuum hose on the T in picture 2 wraps around the dash hose hanger and goes to the center port of the wiper switch. The front small port of the wiper switch has a smaller vacuum line that goes to the small top inlet port on the wiper motor. The vacuum line attached to the rear outlet of the wiper switch extends to just before the wiper motor where you have a split metal connector. One outlet of that connector goes to the large outlet on the wiper motor. The other part of that split connector continues down and the hose goes into one of the two window washer ports on the back of washer switch on the bottom front of the dash.

The other port on the washer switch will take the vacuum hose out through one of two small holes in the firewall just above the top of the washer pump on the bottle. This hose then goes into the inlet port on top of the window washer pump. On the side of the washer pump is an outlet port which accepts a smaller vacuum hose that uses the other small opening through the firewall, then that smaller hose goes up to under the center of the front of the dash to a small T connector which you might see in the last picture. Out of that T connect 2 small hoses which take the washer fluid to the connector on the bottom of the wiper transmissions.  As soon as I find the rest of my pictures I will see if I can further confuse you and me on the heater and antenna hose routing.  Again this is how my 47 is set up and I hope it works for your 42.       Bill

[Bill Ingler #7799]

Here is another picture showing the vacuum hose exiting the firewall to the top of the washer pump and the smaller fluid hose from the side of the pump back through the firewall. Bill

[Bill Ingler #7799]

Hi Gary; Here is the heater/ defroster hose routing which I believe is correct. Again I say this is from my 47 and I believe it is the same for 42. Picture 1 below shows the heater hose connected from the left rear of the left head to the cross over pipe to the other side of the engine. Notice the hose clamps ARE NOT double wire but what is called double band clamps. Looking at picture 2 you will see that the heater hose from the cross over pipe goes to the bottom inlet pipe of the defroster. Picture 3 and 4 ( now pictures 3 and 4 have been changed to a PDF FILE WHICH WILL BE POSTED AS A FOLLOW UP POSTING)explain the automatic heating system in the car. This explanation of the heating is from an issue of the Cadillac Serviceman and it will tell you the reason that the hot water goes in the bottom defroster inlet and out the top outlet of the defroster. Notice that when the heater hose leaves the defroster it curves down and goes through a clamp that is held by the bottom back head bolt.

Look at picture 5 and you will see a double hose clamp separating the hose coming from the defroster and the hose coming back to the water pump from the right under seat heater. After this double clamp, the hose coming from the defroster, continues under the floor towards the left heater core. The hose is held to the bottom of the floor by a hose clamp. The hose enters the front pipe of the left heater. The heater hose next leaves the rear pipe of the left heater and goes across and connects to the rear pipe of the right heater. A hose then is connected to the front pipe of the right heater, travels about a foot and is held to the bottom of the floor by another hose clamp. The hose then drops down and is then held by that double hose clamp as shown in picture 3. The hose then continues foreword on top of the frame rail and is connected to a shut off valve(picture 6) which in turn goes through a pipe to the water pump. Now here is where I am not sure if this valve was factory installed or dealer installed. I have seen this valve on two so called very original cars yet I can not find the valve listed in the Master Parts book. Maybe I am looking in the wrong place in the parts book. Does anyone know for sure if the valve was factory or dealer installed.  Gary I hope this helps with your installation. I have just been told that I will have to post pictures 3 and 4 on a follow up posting as all the pictures together are too large to post.   Bill

[Bill Ingler #7799]

Explanation of the 42-47 Cadillac Automatic Heating System

I had to change pictures 3 and 4 unto a PDF file to post. Sorry about that.

[Bill Ingler #7799]

Gary: I think the last thing to cover is the routing of the antenna vacuum lines and antenna cable. As said up on the right side of the radio near the top you will find 3 vacuum ports. The middle is for the main vacuum from the engine. The outer two ports connect the vacuum lines that go to the antenna on the left fender. The vacuum lines leave the radio and travel down the inside of the firewall and exit a hole behind the windshield washer bottle and then go across the left firewall to the antenna. Look at the picture below. The red arrow points to the vacuum antenna lines.

Now the antenna cable wire is connected to the radio on the back of the radio near the top left. It is a bayonet type connection. Coming from the antenna you can see the small black wire in the picture below with the yellow arrow. It enters the firewall the same place as the vacuum antenna lines.  Please call me in Scottsdale at 480-488-5853 if you have any questions.   Bill