GILLIG LOW FLOOR, Руководство по обслуживанию

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Brakes & Wheels
270
Removal and Installation of Rear Brake Chambers
The following instructions are for rear brake chambers. Instructions
for front brake chambers are similar, except the front chambers do not
have a spring brake chamber.
Before proceeding to replace a brake chamber, make sure that the brake chamber being replaced was
properly installed with the correct push rod length. See also “Brake Adjustment.”
1. Manually release the spring brake following the steps in the previous section.
2. Remove the cotter pin from the yoke pin, knock out the yoke pin and remove both air lines from
the assembly. Be sure to mark the air line from the inlet port marked Spring Brake for later rein -
stallation reference.
3. Using a 15/16" wrench, unscrew hex nuts on mounting bolts and cautiously remove the old
chamber from the mounting bracket.
4. Remove the hex nuts and the flat washers on the mounting bolts of the new chamber. Clean the
face of the mounting bracket and install the chamber on the bracket with close attention given to
positioning the chamber air inlet ports for correct alignment to the vehicle air lines. Then install
one flat washer and hex nut on each mounting bolt. Next, using a 15/16" hand wrench (do not
use an impact wrench) , tighten nuts to the recommended 100–115 ft-lb. If necessary, reposition
the air inlet ports for proper mating and alignment with vehicle air lines.
Position the non-pressure chamber end of the breather tube in the upper half of the chamber fac-
ing away from the road surface. Failure to do so may void the MGM Brakes Warranty.
5. Cut the service pushrod of the new unit to the correct size as follows:
a. Make sure that the spring brake is fully manually released as described in the “Manual Re -
lease” section of this chapter.
b. Make sure the service brake piston is fully retracted into the brakes “OFF” position.
c. Cut the rod at a length of 1-3/4", measuring from the outward bottom face of the service
brake.
6. Reconnect the yoke to the push rod of the brake chamber.
7. Reconnect the yoke to the slack adjuster. Be sure that the correct diameter and length of yoke pin
is installed into the correct hole in the slack adjuster. Secure the yoke pin with a new cotter pin.
(See also “Installing Haldex® Automatic Slack Adjusters” in the “Automatic Slack Adjusters”
section of this chapter.)
8. Inspect the pushrod to be sure that it is working free, not bent, not binding and is square to the
chamber bottom within ±3° in any direction at any point in the stroke of the chamber. If the
pushrod is not square, make corrections by repositioning the chamber on the mounting bracket
and/or by shimming the slack adjuster to the right or left on the camshaft as required.
9. Apply Teflon tape or sealing compound to the hose fittings and reinstall both of the air lines to
the chamber being sure each is mated to the correct air inlet port according to markings made
earlier. The fittings should be tightened to 25 ft-lb into the chamber air-inlet ports.