March brake thought for the month. Hardware
Posted: March 4th, 2013, 2:38 pm
The proper hardware for a drum brake system is critical. So is the quality. I have found some of the offshore stuff less than desirable and use Bendix US made kits. Part numbers H7162 and H 7179 is what I use. I do not have to double up the return springs with good quality kits either.
Using the proper hold down springs is critical. If the pin is too short, the shoe will not be free enough to move and float to match the drum, a pin too long won't hold the retaining clip and could cause real problems. The hold down spring should be tight enough to stabilize the shoe and still allow it to move fore and aft. I always bump the shoe back and forth with my palm to make sure they're free. A sticking shoe is a major reason for rubbing shoes while adjusting.
The shoe tends to move towards the adjusters when the wheel cylinder expands. If you have the improved, later model angled adjusters, this movement will tend to move the shoe outwards towards the drum and maximize the contact area. If the hold down spring is too tight or if the contact points on the backing plate are grooved from wear, this sliding action is impaired.
If you are finding bent pins on the hold down assembly, chances are they are too short and binding the shoe.
Next month's subject will be drums. Be safe out there.
Using the proper hold down springs is critical. If the pin is too short, the shoe will not be free enough to move and float to match the drum, a pin too long won't hold the retaining clip and could cause real problems. The hold down spring should be tight enough to stabilize the shoe and still allow it to move fore and aft. I always bump the shoe back and forth with my palm to make sure they're free. A sticking shoe is a major reason for rubbing shoes while adjusting.
The shoe tends to move towards the adjusters when the wheel cylinder expands. If you have the improved, later model angled adjusters, this movement will tend to move the shoe outwards towards the drum and maximize the contact area. If the hold down spring is too tight or if the contact points on the backing plate are grooved from wear, this sliding action is impaired.
If you are finding bent pins on the hold down assembly, chances are they are too short and binding the shoe.
Next month's subject will be drums. Be safe out there.