Arizona republican., 1918-08-11
POWER DRIVEN
 TIRE PUMP |S
 BEST OF KIND

It IS rather nice question to deter mine just what accessory pays the greatest dividends to the buyer. AL most every advertiser of extra equip ment for the motor car advances claims for the practical money-saving character of his particular pet. There is much to be said for many of these devices. but when it comes to picking out the actual winner of a dividend paying accessory contest, certainly the power driven tire pump is not 10 be ignored.
 All the tire companies assert that the greatest evil against which they have 10 fight is the tendency of car owners to neglect to keep up the imitation of their tires. Under-inflation probably costs the motorists of America more money every year than almost any maintenance failure, except possibly battery neglect. Every car owner should know by this time that when d tire is underinflated the fleXing of the side walls, the weakest part of the tire, induces rapid deterioration of the cas- ing. which will fail hundreds of miles before it's appointed time.
 Now this is just where the power tire pump steps into the breach. It re- moves the labor from initiating the tires and thereby induces the average owner who objects to the back breaking labor of pumping by hand and small blame to him, to keep the pressure up to the proper mark.
 All this supposes that a really eff Cient power pump has been fitted to the car If the power pump is poorly de- signed and frequently out of order, ii will be more of nuisance than the hand pump. So it is important to make wise selection in installing a pump if the car maker has not already done so for you. Incidentally if the car owner has chosen not wisely but cheap ly. it will repay the owner to substitute @ really efficient pump for the one sup piled as equipment on the car.
 Power Pump Complaints
 One of the first ills that will afflict the power tire pump is excessive end play in the crankshaft. In a cheap, spoorly built pump this will probably exist from the day it is installed. In most pumps of today provision has been made 70 prevent any oil being pumped into the casing with the air. IL is not bad plan to hold piece of white paper before the air outlet and see if this preventative apparatus is working properly. Oil pumped into the tire will ruin it in short order. The car owner should inspect his pump from time to time to SC that it is firmly in place and if engagement is carried out by hand, the gears must be kept operating freely. The gauge common ly included in the air line of the power 1,. V-rf1 Ii.41. registering within a few pounds of the actual pressure. but the small hand gauges may usually te depended upon.
 Four Types of Pump
 At the present time there are four distinct types of power tire pumps in common use. The most popular type is the single cylinder affair which operates with an ordinary metal pistcr with crankshaft and connecting rod Another type has sort of flexible leather piston in the shape of a dia- phragm. A third variety of pump ;s driven by engine compression, instead of by mechanical means, while still an- other type gets it's drive from the front end of the crankshaft.
 When the power pump is driven from one of the moving shafts, the trans mission shaft is usually selected for the installation. Sometimes. however an external engine shaft is utilized The advantages of the transmission shaft installation are the removal of a little used device from the engine com partment and the enclosure of the drive, which produces quiet operation and also insures constant and copious fabrication.
 fabrication Important
 The internal fabrication of these pumps is very important matter, since they move at high speeds and are sub- ject to the same fractional tendencies that ordinary cylinders are. In many of the pumps splash fabrication is cm ployed and this calls for good fitting ot rings and piston to prevent excess oi from reaching the tire. Most standard models now have some sort of protec-