Remanufactured brake shoes can save your customers money and therefore many truck owners find them a viable alternative to new shoes.
In order to be the brake expert for your customer, you need to understand what is involved in the remanufacturing of a heavy-duty brake shoe.
Truck Parts & Service spoke with Doug Wolma, general manager of ArvinMeritor’s Remanufacturing Business. Wolma walked us through the step-by-step process used to remanufacture a brake shoe to ensure it will safely stop a vehicle.
Once a technician takes a brake shoe off a truck, he sends it to a remanufacturing center where it undergoes an initial visual inspection.
“There are criteria we use to evaluate whether the shoe is recoverable or not,” Wolma said. The main reason a shoe is rejected is if the cam or anchor pin end has become mushroomed.
“That means it is deformed and it can’t be brought back into shape by coining it,” he explained. In addition, if the webbing on the bottom of the shoe that holds the pin in place is cracked along the weld, the shoe will be rejected.
Once a shoe has been accepted, it is washed to remove grease and other buildup. Then the shoes are delined, a process by which the friction material is pulled off the brake shoe.
“What you are left with is the steel shoe, which then goes through a shot blast process,” Wolma explained.
Steel shot is thrown at the shoe to remove rust, grime and paint. “When the shoe is out of the shot blast process it actually is virgin metal,” according to Wolma.
The next process is to make the curve of the shoe exactly the way it was when it was originally manufactured. “The shoe is placed in a coining press, which reforms the shoe over the top of a die so that it comes out with the exact same contours as the shoe had originally.”
The shoe is then inspected and gauged to make sure it meets all of the critical dimensions and is in spec. (See sidebar on page 23 for a list of what gets inspected.)
The last step in the process is painting the shoe so that it does not rust.
“After the painting is complete, the shoe is sent to the assembly line just like a new shoe, where the friction material is riveted onto it,” Wolma said.
In addition to the cost savings provided by a remanufactured shoe, there are environmental benefits as well. “If you did not remanufacture, you’d have all the steel hitting scrap hoppers and you’d have to figure out how to dispose of it,” he said.
Truck Parts & Service wondered about the quality of remanufactured brake shoes. “If someone remanufactures a product, it is as good as new,” Wolma said.
“And speaking frankly, my position always has been that I believe a remanufactured product is better than new because we make the remanufactured product to all of the original OEM specs.
“But we also inspect everything 100% of the time. Every piece part gets inspected for critical characteristics 100% of the time,” he said.
In addition, the remanufactured parts also take away initial mortality problems.
“When something is cast or forged and it has some sort of inclusion or small crack, it will fail very early in its life. However, it is impossible to detect some of these problems.
“With remanufacturing, you have a part that has gone through field testing and has passed. Therefore if you recover it and bring it back to the critical dimensional characteristics, you have a product that is even better than it was in its early life,” Wolma said.
Remanufacturing vs. Rebuilding
Although remanufacturing and rebuilding involve reusing parts, there are significant differences. According to Doug Wolma, general manager of Arvin-Meritor’s Remanufacturing Business, “A rebuild is when you take a component-a transmission, an axle, an engine or a brake shoe-pull it apart and put it back together using the same parts.
“Remanufacturing is taking all of these components in large quantities and then having a department that pulls everything apart and a department that does all the refurbishment and inspection and then puts everything back together.”
He used the example of a transmission. There are 20 to 50 gears on a transmission. “A rebuilder will take the transmission apart to a certain degree. He may leave the main shaft assembled but will pull down the countershaft. He will replace seals and bearings and then put it back together.”
In remanufacturing, every piece of the transmission gets completely disassembled and then each piece gets inspected to ensure that the parts are reusable.
“Then all those pieces are stored on a shelf just like new parts would be in a manufacturing plant and now those parts can be used to build a remanufactured transmission,” Wolma explained.
“In remanufacturing, you use gears and parts from a multitude of different core transmissions instead of using all the same parts to rebuild the same product.”
Remanufacturing Inspection
According to Doug Wolma, general manager of ArvinMeritor’s Remanufacturing Business, the following items always are inspected as part of the company’s brake shoe remanufacturing process.
Refurbishing Criteria
- Corrosion
- Bad welds
- Bad cam-anchor spread
- Double holes
- Oversized holes
- Table thickness
- Bent tables
- Missing spring pin
- Can wear/mushrooming
- Deformed/broken web
- Worn anchor-pin or spring-pin holes
Riveting Criteria
- Rivet clench, curl
- Lining/table gap
- Lining grade
