0:01 Hi, I'm Mark Shaughnessy and I'm an
0:03 instructor in the training department at
0:05 Coast Mountain Bus Company. In this
0:07 video, I'm going to demonstrate how to
0:09 check brake adjustment using this model.
0:11 You will be required to perform a brake
0:13 adjustment on this model prior to your
0:16 road test. And on road test day, you
0:18 will be required to verbally describe
0:20 how to check brake adjustment. The tools
0:22 that you'll need to check brake
0:24 adjustment are a brake buddy. This end
0:26 is used to apply leverage to the slack
0:29 adjuster. And this end has a 9/16
0:30 wrench, which we use to turn the
0:33 adjusting bolt. You'll also need a ruler
0:34 to check push rod
0:36 travel. There are two ways to check
0:38 brake adjustment. The free stroke and
0:41 the applied stroke method. With the free
0:42 stroke method, I want to first make sure
0:44 that my rear wheel is blocked in both
0:46 directions and that my parking brake is released.
0:48 released.
0:50 I'm going to take my brake buddy and my
0:53 ruler and I first want to visually note
0:56 the position of the push
0:59 rod. Apply leverage to the slack
1:02 adjuster and measure the push rod
1:04 travel. It can be no more than 3/4 of an
1:08 inch on both manual and automatic slack
1:10 adjusters. The ideal measurement is a/4
1:14 of an inch less than that or 1/2 in.
1:16 If the brakes are properly adjusted, I
1:18 can move on to the next wheel. If the
1:20 brakes are out of adjustment, as this
1:22 one clearly is, then I'm going to take
1:25 my brake buddy and using the 9/16
1:27 wrench, press down the locking collar on
1:31 the adjusting bolt and tighten it fully,
1:34 making sure that the cam shaft is
1:36 rotating in the same direction that it
1:39 did when the brakes were applied.
1:41 I'll then use the brake buddy to apply
1:43 leverage to the slack adjuster and make
1:46 sure there's no movement in the push
1:51 rod. Take the 9/16 wrench. Back off the
1:53 adjusting bolt a quarter to a half a
1:56 turn. Make sure that the locking collar
1:58 returns to the raised
2:02 position. Note the position of the push
2:06 rod and retest it.
2:09 It can be no more than 3/4 of an inch on
2:12 both manual and automatic slack
2:15 adjusters. Using the applied stroke
2:17 method, I want to make sure that my rear
2:19 wheel is blocked in both directions and
2:21 that my parking brake is released. I
2:23 want to visually note the position of
2:26 the push rod. And I'm going to ask my
2:28 partner to make a brake application of
2:31 between 90 and 100 PSI while I measure
2:33 the push rod travel.
2:36 It can be no more than 1 to 3/4 in on
2:38 vehicles equipped manual slack adjusters
2:40 and no more than 2 in on vehicles
2:42 equipped with automatic slack
2:44 adjusters. If the brake is in
2:46 adjustment, I can move on to the next
2:48 wheel. If the brake's out of adjustment,
2:50 then I need to adjust it. I'm going to
2:53 take my brake buddy and using the 9/16
2:55 wrench, I'm going to press down on the
2:57 locking collar and tighten the adjusting
3:00 bolt fully, making sure that the cam
3:02 shaft is rotating in the same direction
3:04 that it did when the brakes were
3:07 applied. I'll then back off the
3:11 adjusting bolt a/4 to a half a turn,
3:13 note the position of the push rod, and
3:15 ask my partner to make another brake
3:18 application of between 90 and 100 PSI. [Music]
3:21 [Music]
3:23 Make sure that the locking collar
3:25 returns to the raised
3:28 position to be no more than 1 and 3/4 in
3:30 on vehicles equipped with manual slack
3:32 adjusters and no more than 2 in on
3:34 vehicles equipped with automatic slack
3:36 adjusters. Automatic slack adjusters
3:38 must be checked and serviced at regular
3:41 lubrication intervals by a certified
3:44 mechanic. In an emergency, automatic
3:46 slack adjusters can be adjusted
3:47 manually, but you must follow the
3:50 manufacturer's instructions. You must
3:52 then get them serviced or replaced at
