VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 31 Cabriolet - Need Info on Wiper Vacuum lines

The information I am requesting can come from anyone with a closed car Fisher Body 1931 regardless of model as the information I am requesting is essentially the same regardless of the 31 Fisher Body Model.

I have a 31 Cabriolet with the original 194 Cu in Stove Bolt 6.
At sometime an earlier owner removed all vacuum lines and connections for the windshield wiper. I still have the Wiper Vacuum Motor Control Box with a slide on/off switch that I am going to have rebuilt.

Information Needed:

1. Can someone take measurements of their 31 to provide the exact location, size of hole, type and size (OD) of fitting into the manifold. Is it a 45 degree or 90 degree fitting? Is it Brass, or other type of metal (describe)?

2. Type of vacuum line (hard or soft) and OD and ID of line.

3. Length of vacuum line to firewall transition;

4. Type of fitting (if any) that goes through the firewall (Describe fitting (if any) or is it just a grommet that the vacuum line runs through and continues uncut to the Wiper Vacuum motor?

5. As I understand it, the vacuum line once through the firewall, is routed behind the interior Cowl and is routed through a channel on the backside of the interior Cowl and there are built-in clips that hold the vacuum line in place. Is this correct?

6. Then the vacuum line is routed through a hole on the drivers side of the cowl and is joined to the slip fitting on the vacuum motor contol. Is this correct?

I would greatly appreciate all pictures of this routing process, as the vacuum line and connector to the manifold is missing from my car. I want this restored just as it was when the car was assembled.

Thank you for your help.

Perry A. Seaton

?????

Do you mean the vacuum wiper motor?

Yes.

I'm not sure the routing for a cabriolet is same as for a closed car, but here goes.

About 2" from cowl end of top of intake manifold is a threaded hole to take a brass fitting which has a barbed end sticking straight up. A 3/8" OD rubber vacuum line connects to this fitting and rises about 8" before exiting into firewall through a grommet suitably sized (available from FS). Rubber line enters inside area under dash near steering column and runs toward drivers side where it connects to a 1/4" OD copper vacuum line. This copper line runs horizontally to windshield/door post(A pillar)and then runs vertically within door/windshield post sheetmetal until it comes out top at header panel. The copper line then runs along windshield header about 10" to a 1/4" hole in header panel where it turns 90 degrees and exits to outside of header about 3/8". Copper line in this area is secured to inside of header panel by 2 metal clips spot welded to header panel. The Wiper motor is secured to the outside of header panel with 2 bolts into a triangular bracket screwed to header panel. A short piece of 3/8" OD rubber hose connects the motor to the copper line protruding through the header. Related, the motor switch is turned on/off using a specially bent steel control rod which goes through header (small hole in lower lip) and above windshield regulator to a mounting above windshield crank. This is how my '31 Coach is set up.

On a cabriolet, from the firewall to the wiper motor is completely different since the wiper motor is at the base of the windshield, not on top.

The Guys are right! A Cabriolet/Landau are very different then any fisher body. First off the line is Chrome plated and I have been looking for the correct tubing to copy for a long time. Is it steel or copper, dose it have a rubber conector at the wipper motor or stright into the motor? I have not found any documentation on that as of yet. Also your motor is to the chrome.

The tubing from the manifold toward the firewall is the same. One source shows it to be 2 5/8" x 3/16" OD copper and fitting to connect it to the intake manifold. A fabric covered hose connects that to a chromed (or stainless) tube that has a few bends (don't have one to be more specific) ending just before the wiper motor intake port. A short piece of hose connects to the wiper.

Thank you for the information. I am going to have my auto restorer fabricate one.

As to your search, I would take a guess that the line is copper that is shaped to the proper bends to run behind the dash and then turn and come through the chrome moulding and anoher short bend to line up with the vacuum motor nipple. A short piece of rubber vacuum line would make the connection from the copper to the vacuum nipple. After everthing has been dry fitted so you are sure it is bent correctly, then the copper line could be sent for chroming and you are in business.

I have found in restoring this car that the little things that you would assume would be easy to find are actually the biggest pain in the neck! Good luck with your project.

Perry A. Seaton

Thanks. Information is very helpful.

32 Confederate:

I found a line that is close to what had been installed originally. Snyder's (they are Model A parts suppliers) has a Stainless Steel vacuum line that is able to be shaped (just like copper tubing. This line was designed to run wipers on a Model A. You may want to contact them and check it out. Good luck on your project.

Snyder’s Antique Auto Parts, Inc. 12925 Woodworth Rd., New Springfield, Ohio 44443
Toll Free (888) 262-5712 Local (330) 549-5313

--Perry A. Seaton