Packard Forum Index » Post-War (1946-54)

Does anyone have a diagram of the vacuum lines from the distributor to carb and to windshield wiper motor. My car( 48 Deluxe ) has a can tank mounted on the engine cowl - Trying to determine if this is original, aftermarket, or neither. Also are the lines metal or rubber ? Thanks

The can is not original & I don't think there ever was a diagram published by Packard.

The distributor tube is a small steel line and comes off front of carb base straight across engine and drops down to a clip in the plug wire holder and then to dist vac advance unit.

Believe on yours the wiper vacuum supply starts at front of intake manifold & drops down to top of pump exhaust side. Thru pump & out inlet side. From pump via a steel tube along side of engine block in that space just above pan to rear where it bends up a few inches at the firewall and changes to a rubber hose. If there is a vacuum antenna or other small vacuum options believe there will be a tee in that short length of hose just before wiper motor to supply the options. Vacuum antenna would get it's supply from the tee via a rubber hose to the grommet near side of cowl and in to valve. Hoses from valve to antenna out the grommet and then drop under fender to antenna

If you have the Electromatic clutch, that supply is a large steel tube from clutch control valve, straight across engine where it drops down and goes into a large fitting in manifold just below carb. The power unit tube is steel from control valve, goes forward along drivers side of engine where it turns 90 degrees and down to a short hose connecting to power unit.

All factory tubing is steel -- although some pumps had solid steel & fittings connections for the vacuum and others had short rubber hoses between the pump and steel lines.

Thanks HH - I hope you can understand what I have here. The steel line from carb to vacuum advance has a tee which is plugged- I assume it had a hose going to wiper. - Are you saying the wiper is powered off the fuel pump (vacumm ) ? I have a rubber line coming off the fuel pump to the can and then on to wiper motor. Also, what the does other side off wiper motor go to ?

The fuel pump is a double action fuel pump. You can run the wipers off the intake. The dual action fuel pump was to even out the drop in vacuum

The fuel pump is a double action fuel pump. You can run the wipers off the intake. The dual action fuel pump was to even out the drop in vacuum

Why they would mess with the vac advance is a question --- unless that can is for some kind of aftermarket pollution device. I know there were some of those aftermarket devices that messed with timing advance to try and lessen oxides of nitrogen emission. Coming straight off the pump, I don't think that very likely but you never know. Perhaps it was some attempt to increase vacuum to the motor. You would have to trace things very carefully to try and determine exactly where it goes and what it does.

Here are a couple of illustrations from parts manual. I drew in a basic approximation of the wiper vacuum supply. The photo is one provided by BDeB & shows the rest of the wiper supply route and the take off for vac antenna. Typically, the other side of wiper motor connection is for the optional windshield washer -- but that use depends on the particular washer installed.

Normal operation is the intake manifold supplies the vacuum. When the engine is under load or throttle is nearly wide open, vacuum drops enough that wiper motor can stop. The pump is in series with the intake manifold source so if vacuum drops from intake manifold, pump will take over and provide a lesser amount but still enough to keep the wipers going at a reduced speed.

Attach file:

---

  (73.98 KB)


  (68.99 KB)


  (129.37 KB)

Thanks for the pics - guess I don't even need a line coming off the vacuum advance line , just the one from fuel pump ?

Check out my restoration blog. I installed all new metal lines. Mine are a bit neater than the originals, but follow the same general path. The following pics show the lines best:

177
219
226
227
253
254

packardinfo.com/xoops/html/modules/newbb ... lat&order=ASC&type=&mode=0&start=30


Jeff

Thanks Jeff for the incredible pictures in your blog. Everyone should be grateful - Only thing, it makes me want to call the scrappers to pick up my car. Thanks

I remember in the late 70's, California started a SMOG program to control NOX. the program required all annual auto registrations to get a SMOG kit added on the car. There were two kits, one was a green vacuum switch in the upper radiator hose and was in the middle of the vacuum advance and the vacuum source. If the sensor in the radiator hose got too hot, it opened and allowed vacuum to go to the vacuum advance. The second kit for the cost of $25.00, consisted of an instruction book and two rubber caps, one on the vacuum advance port and one rubber cap on the carb vacuum source.