Auto Service World
Feature   October 1, 2001   by Rick Cogbill a.k.a. Slim Shambles

That Sinking Feeling

"Here he comes again!" We looked out the coffee room window just in time to watch Hooch Rambler pull in the driveway, roll by the shop and leave by the other exit. This was his third time through."May...

“Here he comes again!” We looked out the coffee room window just in time to watch Hooch Rambler pull in the driveway, roll by the shop and leave by the other exit. This was his third time through.

“Maybe he’s lost,” I said, watching his Ford pickup disappear around the block with the brake lights flashing.

“Or else he doesn’t want to disturb us while we’re having coffee,” offered Beanie.

“Not likely,” groused Tooner. “Hooch ain’t one to worry about stuff like that.”

Basil squinted over the top of his playing cards. “Well, whatever the reason is, he’s back.”

This time Hooch was going much slower. Shutting off the engine, he jerked to a stop by throwing the shifter into Park. The driver’s door burst open and Hooch stumbled out of the cab to give the pavement a loving embrace.

“Having trouble with the brakes?” I asked as I went out to meet him.

Hooch staggered to his feet and grabbed me by the shoulders, wide-eyed and breathless. “Slim! Ya gotta fix my brakes; they’re awful!”

I tested the brake pedal and had to agree. It sank to the floor like a rock in quicksand.

Beanie carefully drove the truck onto the hoist (Hooch refused to go near it) and after verifying that there were no external fluid leaks at the lines, calipers or wheel cylinders, we ordered up a new master cylinder from Herkle’s Auto Parts.

“By the way, Slim, what about that fall booking program I asked you about?” asked Herk. “I’ve got washer fluid on special.”

“Ah, I’ll catch up with you later on that, Herk,” I said. “I’m kinda busy right now!” I hung up quickly. The last thing I wanted to do was fill up my parts room with fall booking programs.

Beanie installed the new cylinder and bled the system. “Hey, Boss! This one feels just as bad as the other one. D’ya think we got a bum part?”

“Could be,” I sighed. “It wouldn’t be the first time.” Dealing with faulty parts right out of the box is no way to have fun, but Herk sent a new cylinder up right away. He always stands behind his parts. But I also noticed a Fall Parts Program flyer stapled to the invoice. If there’s one thing Herk knows nothing about, it’s being subtle.

But we still couldn’t get the third master cylinder to hold pressure. We were stumped.

Basil noticed our plight. “Before you order another one,” he said, “let me try something.”

After disconnecting the rear brake line from the master cylinder, Basil installed a metal pipe plug. “Try it now,” he said.

Beanie tested the pedal. “Solid as a rock!” he exclaimed. “What gives?”

Basil pointed to a valve assembly mounted in the brake lines, down between the frame and the engine block. “You’ve got a faulty Electro-Hydraulic valve,” he said. “Ford calls it a modulator valve. 1987-90 Ford, GM, and Dodge trucks with anti-lock rear brakes use one.” He explained how the internal dump valve can be held open by debris, causing brake fluid to flow into the accumulator and create a situation very similar to a bypassing master cylinder. “By blocking off the rear brake lines at the master cylinder,” he continued, “I’ve taken that valve out of the system.”

After solving Hooch’s problem by installing a new modulator valve, I called him up with the good news. All the same, he arrived with a coil of rope and a boat anchor over his shoulder. “Ah aim to be prepared,” he muttered.

The last order of business was to convince Herkle’s Auto Parts to take back the two master cylinders we didn’t need. Herk was gracious about it and I only had to agree to one small concession.

“Gee, Boss,” said Beanie, scratching his head as the parts truck drove away. “What are we going to do with 60 cases of washer fluid?”

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About The Writer

Rick Cogbill is a freelance writer living in the Okanagan valley of Southern British Columbia. A licensed technician with over 25 years in the automotive repair industry, including ten years as a shop owner, Cogbill creates his comic scenarios with Slim, Basil, Tooner, and The Bean out of actual case histories. “What you have just read is true,” drawls Slim Shambles. “Only the names have been changed to protect my hide!”

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