"Oh, well
- let it slide," Jack Simpson said carelessly to Harry, the Model Garage's
earnest young mechanic. "Probably it doesn't amount to anything - but if it
does it'll get worse, and then we won't have any trouble locating it."
Gus Wilson
had come in quietly from an errand downtown was hanging up his coat.
"That's one way of owning a car, Jack," he remarked, "and, to tell the
truth, it's a pretty popular way. But it's often a darned expensive one.
What's your trouble?"
"Oh hello,
Gus. I didn't see you come in," Simpson said. "Why we were on our vacation
last week we had a little difficulty - left rear wheel brake dragged a bit.
I had the people in the garage of the hotel where we were staying look at
it. They said that something had gone wrong with the brake cylinder in the
wheel, and charged me three bucks for adjusting it. Now Peggy says that all
the brakes drag a little - I haven't noticed it myself - and she thought I'd
better some in and let you take a look at them. But there doesn't seem to
be anything really wrong, so I guess it isn't worth bothering about."
"What did
they do to that wheel cylinder?" Gus wanted to know.
"I dunno,"
Simpson admitted, grinning. "I was playing golf while they were working on
it, and afterward I never thought to ask them."
"Peggy's a
smart, girl," Gus assured him. "But she wasn't so smart when she married a
guy who lets his car cost him more than it should just because he's too
careless to check up on the little things. You'd better leave your car here
for a couple of hours, Jack, and let me give those brakes a good looking
over."
"All
right," Simpson agreed. He had barely left the garage when Joe Clark stuck
his head in at the office door. "Hurry call for the wrecker!" he
announced. "From Old Man Parsons. Says he couldn't get his car started
this morning. Wants you to tow it over here and fix it up - and he's got to
have it back in an hour Better step on it!"
Half an
hour later, Harry drove up to the shop door, towing the Parsons car. A
peppery Old gentleman was with him, and Gus could see that Harry hadn't been
having a happy ride.
"It's
preposterous!" snapped Parsons, jumping down as soon as the car stopped.
"Mr.
Wilson, my car was overhauled here less than two weeks ago. When I paid my
bill, Mr. Clark assured me that everything was in excellent condition. But
this morning my car refused to start! I tried. My next door neighbor
tried. Then his hired man attempted to turn the motor over with a crank
But it was no use. I had to walk to my office - and I was ten minutes
late! I insist that you - "
"Sure
thing, Mr. Parsons," Gus said soothingly. "I'll fix things up. Roll her
in, Harry."
Gus tested
the battery. It was strong, but not nearly strong enough to kick that halky
engine into action He tried everything he knew, but he couldn't get the
engine to turn over. Harry, watching him, saw that for once he was
thoroughly stumped.
While Gus
was scratching his ear, Harry aimlessly pulled out the oil-gauge rod and
looked at it. Then he looked at it more intently, and held it out for Gus's
inspection. It was covered with a gummy substance as thick as transmission
grease.
"What sort
of oil have you been using lately, Mr. Parsons?" Gus asked.
"Oil? The
oil that you put in my car!" the customer replied tartly. "I've been
driving very little, and have had no occasion to add any."
Gus poked
an exploring forefinger into the messy stuff on the gauge rod, then touched
the smeared finger to the tip of his tongue, and frowned. "Drain the oil,
Harry," he directed. It oozed out very slowly and was thick and gummy. An
examination of the engine showed that pistons and bearings were sticky with
it.
"You'll
have to leave your car with us for a day," Gus told the car owner. "We'll
have to take the engine apart, and clean it thoroughly. Some one played a
little joke on you - a mean one, too. They put sugar in your oil, probably
while you had your car out last night. I can taste it - and I saw that
trick pulled once before. Your drive home was just long enough for the sugar
to dissolve in the oil and turn it into a gummy grease that set hard while
the car was standing overnight, and stuck the pistons to the cylinder walls
so tight that the engine can't turn over. There won't be any permanent
damage, but it's going to be pretty close to a day's job getting the mess
cleaned up."
"Hooligans!" reared the customer. "I'm going to the police and see to it
that they - "
He went
out fuming. Gus and Harry looked at one another, and couldn't help
grinning. Then Gus shook his head. "It's nothing to laugh at, at that," he
said. "It was a dirty trick - the sort of bum joke that causes a lot of
trouble and expense. I suppose that some of the kids around town have it
in for the old grouch, and maybe he had it coming to him - but I do hate to
see an engine abused! Well we'll get at the clean-up job tomorrow. Now
let's get Jack Simpson's brakes checked. I'll drive his car around the
block a couple of times, and see how they act.."
When Gus
drove back into the shop, ten minutes later, he beckoned Harry over to the
car. "Hop in here and step on the brake," he said as he got out. "Then
tell me how it feels to your dainty little size fourteens."
Harry got
in and pressed his foot down on the brake pedal. "Feels as if it was
working on a wet sponge!" he reported.
Gus
nodded. "That likely means one of two things," he said. "Either that the
brake shoes are out of adjustment, or that air has somehow got into the
hydraulic system. But there's something else. All four brakes on this car
drag a little - just as Peggy told Jack they did."
"It
usually is a sign that you've got a quite a job on your hands," Gus told
him. "You're clear on how hydraulic brakes work, aren't you? When you
press your foot down on the brake pedal, the pedal's connection forces the
piston of the hydraulic system's master cylinder inward. That exerts
pressure on the brake fluid in the master cylinder, and forces some of it
through the copper pipes that connect the master cylinder with each of the
four wheel cylinders. Then the fluid exerts equal pressure on the pistons
of each of those four cylinders."
"Sure,"
Harry nodded. "But what makes Simpson's brakes drag?"
"Well,"
Gus went on, "the pressure exerted by the brake fluid on the wheel-cylinder
pistons forces them outward against the brake drums, creating friction that
causes the brakes be drag a little
"When you
take your foot off the brake pedal, the pressure from the master cylinder is
removed from the wheel-cylinder pistons. Then the return springs on the
brake shoes force the pistons inward, and the pistons force the brake fluid
back into the master cylinder."
"On this
car the brakes drag - they don't return promptly to the 'off' position when
the pressure of your foot on the brake pedal is removed. If only one brake
dragged, the most likely cause would be a return spring that wasn't working
property. Maybe all that would be necessary would be to clean it off well;
but more likely it would have lost its contracting power, in which case
you'd have to put in a new spring.
"But when
all four brakes fail to return promptly to the 'off' position it's a sure
sign that the trouble is in the entire hydraulic system. And it's almost
certain that it is caused by engine oil or kerosene - any mineral oil -
having somehow got into the brake fluid. Even a very little of it will
cause the fiber cups in the master and wheel cylinders to swell out of
shape, so that the cylinders will not work property. When that happens the
brake fluid is prevented from returning promptly to the master cylinder, and
its pressure keeps the brake bands in contact with the brake drums, and
causes drag.
"Remember
what Jack said about having some trouble with one of his wheel cylinders,
and having it taken care of at the garage attached to a country hotel?
That's the tip-off. In fixing the cylinder the garage men probably washed
its parts in kerosene, and the kerosene has worked all through the hydraulic
system. See here - "
Taking the
cylinder apart, he showed Harry how the fiber cups were swollen and
distorted.
"Now let's
get busy!" he said. With Harry's help he removed all the cylinders. After
washing the parts thoroughly with brake fluid, Gus replaced the cups with
new ones, and reassembled and replaced the cylinders. Then he did the same
thing with the master cylinder. After reconnecting the pipes with the
cylinders they filled the tank with fresh brake fluid that they pumped
slowly through the system to flush it out and to bleed the air out of it.
Then Gus replaced the bleeder screws, permitting no air to get into the
brake lines, and gave the brake shoes a careful adjustment.
"I'll try
her out," he said. After driving around the block once he came in
whistling.
"That did
it," he said. "That spongy feeling of the brake pedal is gone, too - they
must have got air as well as oil in the system when they fixed that
cylinder."
"I'll
admit that you're pretty good-good as a brake-testing machine," Harry told
his boss. "Say, Gus - what else can you find out about brakes by just
stepping on the brake pedal?"
"Quite a
lit," Gus assured him. "If the pedal goes all the way down to the floor
boards under moderate pressure, it's usually an indication that the brake
linings are badly worn - or, less frequently, that the brake shoes aren't
adjusted property, or that there is either a leak in the hydraulic system ,
or there's air in it.
"If brakes
squeak when you apply them, it's usually a sign that the brake linings are
dirty - that dust has clogged the pores of the asbestos friction lining and
caused it to glaze over. You can kill the squeak by cleaning the linings
with a stiff wire brush dipped in gasoline, and put on a new washer to stop
the leak.
"Sometimes
a car will pull to one side when you step on its brakes. A possible cause
of that could be that the lining on one wheel is of a different brand from
the linings on the other wheels. Different makes of linings have different
breaking efficiencies, and one lining of low efficiency will make your car
slue to one side. Well, it's quitting time... Just learn to use the old
bean, Harry, and you'll do all right with brakes or anything else in this
business."
While he
had been talking, Gus had been making out a time and material slip for the
Simpson job. He held it out for Harry to see.
"Ran up
pretty high for a little job that Jack thought wasn't worth bothering with.
But if he'd followed that idea of his of letting it get worse before he did
anything about it, it would have cost him a lot more in the end."
END
