HUB-WHEEL 1481167 - Caterpillar

Illustration 1 g00627885
(1) Plug (2) Spindle housing The wear of the brake pack can be determined by viewing the punch mark on the piston. Viewing the punch mark on the piston can be accomplished by removing plug (1) from the drain port and installing a 5P-7389 Transparent Plug Assembly in the drain port.When you install the piston and the new brake pack, make sure that the previous punch mark is aligned with the drain port.Perform the following marking method when a new brake pack has been installed and there is not a punch mark on the piston.
Remove plug (1) from the drain port.
Install a 5P-8678 Marking Punch Assembly in the drain port.
Remove the air inlet line and apply air to the inlet port. This will move the piston to the brake ON position. Do not exceed 965 34 kPa (140 5 psi).
With the piston in the brake ON position, strike the 5P-8678 Marking Punch Assembly. Make a mark that is 2.3 0.8 mm (.09 .03 inch) in diameter.Note: The marking method should not produce any chips inside the spindle housing (2) .
Relieve the air pressure from the brake. Remove the punch assembly from the drain port.
Install the air inlet line and install the plug (1) into the drain port.Note: Before you install the plug, apply 5P-3413 Pipe Sealant to the threads of the plug.Dimension Guidelines for Parts in Service Brakes
The acceptable dimensions for each brake disc and each friction disc are shown in the table which follows. The table lists the dimensions that indicate when a brake pack is worn and/or a brake pack needs inspection. The table also lists the dimensions that are needed for the replacement of parts.Check each friction disc for possible damage. Also, check for burned friction material. If only one surface of the friction disc is worn, the grooves must be at least 0.127 mm (.0050 inch) deep. During brake installation, place the thicker friction disc in the middle of the pack because wear is faster there.
Table 1
Discs    
Part Number     8D-1648    
Quantity Of Discs For Each Brake     7    
New Thickness    
2.31 0.05 mm (.091 .002 inch)    
Friction Discs    
Part Number     6Y-7917    
Quantity Of Discs For Each Brake     6    
New Thickness    
3.81 0.13 mm (.150 .005 inch)    
Reusable Minimum Thickness    
3.28 mm (.129 inch)    
New Minimum Groove Depth    
0.40 mm (.016 inch)    
Reusable Minimum Groove Depth    
0.127 mm (.0050 inch)    
Complete Brake Pack    
New Thickness    
39.04 1.12 mm (1.537 .044 inch)    
Maximum Wear Of The Thickness Of The Brake Pack That Is Permissible    
3.05 mm (.120 inch) (1)    
Thickness For Inspection    
35.99 mm (1.417 inch)    
( 1 ) Inspection is needed when the mark on the brake piston moves out of view of the transparent plug assembly.