New Solid Brake Cross Shaft
A new service brake cross shaft assembly has been designed and is now standard on all cars and trucks. The new shaft replaces the old style cross shaft and equalizer assembly, as the old assembly is obsolete and will not be carried for service.
The new shaft is unusually efficient, simple in design and reduces the number of cross shaft parts.
The following parts are required to install the new service brake shaft assembly for car and truck:
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The following cross shaft and equalizer parts are obsolete and will not be supplied after present stocks are exhausted. If any of these parts are ordered, the parts necessary to install the new brake cross shaft should be furnished at the price of the part or parts so desired.
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When the solid brake cross shaft is installed on cars equipped with adjustable brake rods, it will be necessary to substitute A-2466 adjust- able eye for the A-2461 clevis on the rear rods.
When installing solid brake cross shaft on cars and trucks equipped with hand brake lever at side, an A-2491-R or AA-2491-R cross shaft guide must be installed (see Figs. 603 and 604).
((603 + 604))
The brake rod holes in cross member must also be enlarged to provide sufficient clearance for the brake rods (see Figs. 603 and 604).
When used on cars equipped with solid brake rods, it will be necessary to change the solid rods into adjustable rods.
This can be done by sawing off the ends of all four rods 33″ from the center of the button on the rods (see Fig. 605) and running a 5/16—24 thread back 2″ from the end of the rod, then installing locknut A-21700 and adjustable eye A-2466. The length of the rod measured from the centerline of both eyes should then be adjusted to not more than 51 7/16 or less than 51 1/2 (see Fig. 605).
When installing a solid brake cross shaft on trucks equipped with adjustable front brake rods, it will be necessary to shorten the intermediate rod AA-2500. This is done by sawing 5/8” off either end of rod, threading the rod 2” back with a 5/16—24 die and installing lock nut A-21700 and adjustable eye A-2466. The length of the rod measured from the centerline of both eyes should then be adjusted so that it measures not less than 38 5/8 or more than 38 11/16 (see Fig. 605).
When installing the new cross shaft on trucks equipped with solid front brake rods, it will be necessary to make an adjustable rod out of the front rods in the same manner as described for the car. It will also be necessary to rework the intermediate rod AA-2500 as described in preceding paragraph.
Installation and Adjustment
The oilless type bearings on the ends of the new solid brake cross shaft are assembled to the frame by the use of A-2479-B shims and A-2478-B brackets (see Fig. 606). When assembling, a small amount of grease is required in bracket as the outside of the bearing must rotate slightly inside of the bracket in order to preserve alignment when flexure of the frame occurs.
After installing cross shaft install brake pedal to cross shaft rod. The adjustable clevis end of the rod is assembled to the brake pedal—the non-adjustable end, to the lever on the cross shaft (see Fig. 606).
A slightly different procedure is followed in adjusting this rod depending on whether the car is equipped with a single plate clutch or a multiple disc clutch as the brake pedals used on cars equipped with the single plate clutch are provided with a stop.
If the car is equipped with a multiple disc clutch adjust the rod as follows: Hold the tip of the rod against the rear flange of the center cross member, then adjust the clevis on the opposite end of the rod until the brake pedal arm clears the underside of No. 1 floor board by 1/2” to 3/4”.
If the car is equipped with a single plate clutch, pull the brake pedal all the way back until it is against its stop—then adjust the rod until there is approximately 1/16” clearance between end of rod and rear flange of center cross member (leaving a little clearance between end of rod and cross member prevents any possibility of the end of the rod rubbing against the cross member and causing a squeak).
After adjusting the break pedal to cross shaft rod, assemble side pull rods to brake operating and cross shaft end levers. When assembling the side pull rods, pull the brake operating levers on the front axle back and the brake operating levers on the rear axle forward (taking up all idle movement). Then with the levers in this position adjust the length of the side pull rods so they can be assembled to brake operating and cross shaft end levers.
Next adjust brakes by turning up the adjusting wedges as described on page 202 of the January, 1928, Bulletin.
After the brake rods have been correctly adjusted car owners should be notified that this adjustment must not be altered. Service brake adjustments must be made only by means of the adjusting wedge at each brake.