Worn slide rails on vehicles equipped with pad slide rails (See Figure 16.1)
The slide rails wear due to the tremendous forces during braking and lack of lubrication. The constant force of the brake pads being pushed into the slide rails during braking combined with the constant back and forth movement of the brake pads causes “dimples” to wear in the most used areas.
In theory the only fix to this problem is to replace the part with the worn slide rails. Depending on the application this will either be the caliper mounting bracket or the entire steering knuckle. Neither of these repairs is practical.
The slide rails can be repaired following the steps below:
- Clean the slide rail surfaces down to bare metal taking care not to remove good material. (See Figure 16.2
- Using a MIG welder fill the worn spots making sure to use the necessary settings to get good penetration. Try to avoid building the area up to high. The more buildup the more work. (See Figure 16.3)
- Using an angle grinder with an abrasive sanding disc rough in the repaired area. Use the surrounding surfaces as a reference.
- When close, use a Scotch-Brite disc to perform the finish work. The area can be checked using a straight edge. (See Figure 16.4)
- Check the final repair by sliding the pad the full length of the slide rails while checking for binding.
Using this process will save your customer money, provide a legitimate profit for the shop, and restore the knuckle to like new condition.