Mechanic Says He Always Refuses to Install Parts You Bring Into His Shop. It Sure Sounds Like He’s Right

"Apparently you have never heard of rockauto."

Mechanic says he always refuses to install parts you bring into his shop

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Stacy Fernandez

By: Stacy Fernandez

Oct 14, 2025 at 6:00am ET

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Many car owners have been tempted to save money by purchasing their own parts online and bringing them to a mechanic for installation.

But one auto technician is explaining why this common practice might actually be costing customers more money—and why his shop has a firm policy against it.

'I'm Gonna Always Say No'

In a trending video with more than 3,200 views, John (@autotechjohn) shared why he refuses to install customer-supplied parts at his shop.

"Bringing me your own parts, trying to convince me to put them on for you, I'm gonna always say 'No,' and this is why it benefits you to just accept that," John says in the video.

He uses a restaurant analogy to make his point. "You don't bring your own steak to a restaurant, do you? Nope," he says. "Thing is, I'm getting you a better part for less money."

To demonstrate his claim, John shows viewers his shop's parts ordering system. He pulls up an application called Parts Tek, which is integrated into his shop's Tekmetric system. Using brake rotors as an example, he displays two different prices on the screen.

"These are just standard Duralast rotors. They're kind of a [cheap] rotor. But just as an example, my price is at the top. Your price that you would pay at the sales counter is there at the bottom," John says.

The pricing difference is substantial. "As you can see, I can get them for about half as much as you can," he says, showing that his price is $53 while the retail price is $91.

John explains how this pricing structure benefits both the shop and the customer.

"Therefore, if I charge you a 20-percent markup on that, I'm still saving you 25 percent or more off of your price of the brake rotor," he says. "So I still make money, and you save money."

Do Mechanics Really Get Better Pricing on Parts?

Auto repair shops typically have access to wholesale pricing that individual consumers cannot obtain, according to AutoLeap.

Markup is calculated by adding a percentage to the wholesale cost of a part. Common auto parts typically see markups ranging from 40–60 percent, while specialty parts can have markups of 100 percent or more, AutoLeap explains. High-end or luxury vehicle parts often see markups of 200 percent or more.

A healthy profit margin for auto parts is typically between 20–30 percent, which allows shops to cover operational costs like labor, utilities, and rent while ensuring profit, according to AutoLeap.

The markup covers more than just the part itself. AutoLeap notes that properly setting a markup is crucial for an auto repair shop's profitability, as it helps maintain shop operations and achieve healthy profit margins while covering overhead costs.

Commenters React

“But you’re gonna mark them up more then I get emm for,” a top comment read.

“30-percent markup is standard 20-percent is great deal,” a person said.

“‘List’ is not what they sell to walk-in customers. Also 20-percent markup on your parts is not sustainable and won’t cover your warranty costs,” another wrote.

What do you think?

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Comments

“I don't allow customers to supply their own parts either for this reason AND they frequently bring me the incorrect part. Wasting my time,” a commenter added.

Motor1 reached out to John for comment via TikTok direct message and comment.

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