HOSE AS 2551257 - Caterpillar

start by:a) remove cylinder headb) remove precombustion chambers 1. Put compression on valve spring (2) with tool (A) and remove locks (1).2. Remove tool (A), rotocoil, spring and valve. Put identification on valves with respect to their location in the cylinder head. 3. Check the spring force with tool (B). The spring force is 57.7 2.9 lb. (256.7 12.9 N). The length of spring under test force is 1.766 in. (44.86 mm). The free length after test is 2.05 in. (52.1 mm).4. Do Steps 1 through 3 again for remainder of valves.Install Valves
1. Put clean engine oil on valve stems. Install valve, spring and rotocoil in the cylinder head. 2. Put tool (A) in position on valve spring and install the locks (1).
Locks can be thrown from valve when compressor is released, if they are not in their correct position on valve stem.
3. Remove tool (A) and hit the top of valve with a plastic hammer to be sure the locks are in their correct position on valve.4. Do Steps 1 through 3 again for remainder of valves.end by:a) install precombustion chambersb) install cylinder head