MANIFOLD 1215927 - Caterpillar

Table 1
New Bank Valves    
Model     New Bank Valves     Former Bank Valves    
902     188-6039     172-4143    
906     188-6040     172-4141    
908     188-6041     144-7691    Each new bank valve has four new pilot relief valves. The new relief valves and the former valves that are replaced are listed in Table 2. Refer to Illustration 1 for the location of the new relief valves.Note: For the 188-0878 Relief Valve and the 186-0912 Relief Valve that are obtained through the parts system, adjustments must be made to the pressure settings. The pressure settings that were set at the factory are too high. The relief valves must be reset to the correct settings upon installation. The 188-0879 Relief Valve and 186-0913 Relief Valve are factory set to the correct pressure settings. Refer to Table 3 for pressure settings.
Table 2
New Relief Valves    
Item     New Part Number     Description     Former Part Number    
1     186-0912     Relief Valve     106-8528    
2     186-0913     Relief Valve     174-4778    
3     188-0879     Relief Valve     155-8787    
4     188-0878     Relief Valve     105-7716    
Table 3
Pressure Settings    
Item     Relief Valve     Function     Pressure Setting    
1     186-0912     Bucket (Rod)    
26000 350 kPa (3771 51 psi)    
2     186-0913     Boom    
27600 350 kPa (4003 51 psi)    
3     188-0879     Bucket (Head)    
15000 350 kPa (2176 51 psi)    
4     188-0878     Main Relief    
23500 350 kPa (3408 51 psi)    
Illustration 1 g00699540
(A) Tighten to a torque of 55.0 6.0 N m (40.0 5.0 lb ft). (1) 186-0912 Relief Valve (2) 186-0913 Relief Valve (3) 188-0879 Relief Valve (4) 188-0878 Relief Valve
Illustration 2 g00699543
(B) Tighten to a torque of 14.0 2.0 N m (10.0 1.5 lb ft).(C) Tighten to a torque of 45.0 5.0 N m (33.0 4.0 lb ft). (5) 039-5069 Nut (6) 033-5879 O-Ring Seal (7) 039-5070 Nut (8) 033-6027 O-Ring Seal (9) 186-2487 Backup Ring (10) 9N-1756 O-Ring Seal (11) 186-2488 Backup Ring Each relief valve is serviceable. A 151-4003 Service Kit is available in order to maintain the serviceable parts on the relief valves. The serviceable parts are shown in Illustration 2. The service kit also contains new valve springs. The valve springs can only be obtained by ordering the service kit.