BRACKET AS 4774073 - Caterpillar

Table 1
Required Tools    
Tool     Part Number     Description     Qty    
A     8T-0849     Pressure Gauge Group     1    
B     4C-4890     Hydraulic Test Group     1    
Illustration 1 g00577424
(1) Drain valves for dry air tanks (2) Drain valve for wet air tank
Release the air pressure from the air tanks on the wheel tractor. Open the drain valves on the dry tanks (1) and the wet tank (2) .
Remove the drain valve on one of the dry air tanks (1) .
From Tool (B), install 4M-5317 Terminal Bushing and a hose.
Connect the hose to the 1S-8937 Needle Valve from Tool (B). Connect Tool (A) to the valve.
Start the engine and allow the air pressure to obtain the cut out pressure.
Compare the readings of air pressure gauge on the machine and Tool (A) .
The difference of the two gauges should not be more than 105 kPa (15 psi). If this condition exists, install a new air pressure gauge on the machine.
If a new air pressure gauge needs to be installed, stop the engine and open the drain valve on the reserve air tank. Open the drain valve on the dry air tank until the air pressure on the wheel tractor is purged of all air.
Keep the test gauge connected. The gauge may be used in other tests.