On September 10th we awoke to another beautiful morning. With the exception of a couple of short-lived thunderstorms in mountainous areas, we have only experienced one day of sporadic light rain in the last month on the road. We are aware of this because our Jeep station wagon has vacuum driven wipers.
Wiper explanation: Unlike the electric motor driven wipers of later vehicles, our Jeep’s wipers depend primarily on the vacuum generated by the engine to power them. All other factors being equal, the engine’s vacuum level is inversely proportional to throttle position (i.e. the harder you press on the accelerator peddle, the less vacuum you have to drive the wipers). So, just when you need windshield wipers most, such as accelerating to pass a semi-truck spraying sheets of water off of its many wheels, the windshield wipers come to a halt. ��Only by momentarily lifting one’s foot from the accelerator peddle, will the wiper blades resume their sweep. So one has the choice of continuing blindly on in their attempt to pass the truck before becoming a speck on the windshield of an oncoming truck, or prolong the time in the oncoming lane by lifting one’s foot from the gas peddle. Ascending winding mountain passes in fog or rain with limited wiper action is equally as exciting. In all fairness to the engineers of that day, on our “up-scale” vehicle there is a vacuum pump incorporated in the fuel pump assembly on the engine that is “intended” to supplement the vacuum generated by the engine in low engine vacuum situations; however, its assistance is marginal, particularly if the total vacuum wiper system is not in super prime condition.
So, we generally remember when it has rained by recalling the moments of sheer terror we experienced navigating roads on those occasions. Hope that the insurance company is not reading this.
Anyway, September 10th was primarily a “getting from A to B” kind of day. We set our sights on making the trek from Libby, Montana to Colfax, Washington. We had anticipated a late start out of Libby, as Jean and I both had some maintenance items to take care of; mine being Jeep related and hers of the more personal variety. The trip was uneventful (a good thing for the moment). The Jeep is behaving well. As we approached Colfax, WA, we witnessed a flurry of activity in the fields as the farmers worked to wind up the wheat harvest and ready the fields for planting. In some instances, the farmers had set the fields alight to remove the remaining stubble. We found Colfax to be mainly a no-nonsense farming town. We ate dinner at a Mexican restaurant reported to be the best eating spot in town. The food was good. We ate and retired for the evening.
The morning of September 11th, while Jean made final preparations for our departure, I visited a local auto parts and repair facility to beg the use of an oil can to lubricate the jeep’s generator and distributor bearings. In my haste to get back to the family back in West Yellowstone, I had neglected to do this when I had last had the Jeep greased. The auto repair folks in Colfax did not have an oil can. Not a surprise to me after my previous servicing experiences. However, the auto parts folks across the parking lot did and thankfully lent me their oil can.
Our objective for September 11th was making the 5 hour, 250 mile trek to Packwood, Washington which lay just 11 miles south of the southeast entrance to Mt. Rainer National Park. The most memorable part of this journey was traveling through the large rolling wheat fields of western Idaho and extreme eastern Washington State. Soon after, the scenery returned to semi-arid sagebrush covered hills with an occasional patch of farmland.
After having our traditional picnic lunch at a rest area just over the Columbia River, we again began to see more evidence of agriculture. First there were apple orchards with farm hands hard at hand picking the fruit and tandem semi-trucks whisking along in both directions loaded with large stacks of apple crates. Then came the occasional corn fields and finally large plots of hops; their 10 foot stalks growing up vertical lines suspended from overhead cables.
The final leg of the journey to Packwood, WA included a 10 mile winding stretch of RT 12 where loose gravel had been spread over a bed of tar; relying on vehicles including ours to either embed the loose stones in the roadbed or throw them at oncoming vehicles. Fortunately we made it through that section unscathed and coasted into Packwood in time to have a pizza dinner with some folks from Australia that we met at the lodge.
Terri, you are correct about vacuum wiper systems. When new, they were marginally adequate. When they get old, they stink!
In all fairness, there was a good reason to use a vacuum-operated wiper motor in the early days. One important reason is size. (For example – a vacuum wiper motor for a ’55-57 Chevy is less than half the size of the optional electric motor.)
Prior to about 1940, windshield wiper arms mounted at the top of the windshield instead of the bottom like today, and the wiper motor was often mounted inside the passenger compartment directly in front of the driver. So, avoiding extra bulk near the driver’s forehead was a good thing.
There was also the issue of the adequacy of the car’s charging system. The generators of the day were barely capable of keeping up with the lights, ignition, and perhaps an optional radio and heater blower motor when the car was idling. So, adding an electric wiper motor into the mix may have been a bit too much.
As best as I can tell, Chrysler Corporation began offering electric wipers as an option in 1949, while Chevrolet didn’t offer them as an option until 1955. Vacuum wipers were commonplace through the late 1950s.
I’m learning lots about cars as I read your posts, Dan. Vacuum generated wipers sounds scary!