SPRING-SEALING 7F9896 - Caterpillar

Illustration 44 g03507540Tighten fasteners according to the specified torque sequence, if available. If no torque sequence is specified, then tighten in a star or spiral pattern. Do not tighten adjacent fasteners in order around the perimeter of the bolt pattern.Do not retorque Type-K anaerobic joints because the compound begins to cure immediately after flange assembly. Retorquing will cause the anaerobic to crack and lead to joint failure.Fasteners must not be loosened and retightened. For example, bolts may not be removed to install a bracket, wiring harness clip, then retightened, as the gasket seal will be compromised.Troubleshooting Leakage
There are many factors that could cause leakage to occur during testing. The following is a list of items to check that in the event leakage is detected during a test:
Was the gasket installed?
Is the bolt torque correct? Were any of the fasteners loosened and retightened?
Are the mating surfaces clean, dry, flat, porosity-free, and in good condition?
Is the gasket in proper condition (undamaged, scratch free)?
Does the gasket fit into the joint properly? Is the gasket positioned correctly?
Is the gasket dimensionally correct?
Is the air test pressure appropriate for this type of gasket?Note: Some gaskets require a "settling" period involving time, temperature, or fluid exposure to seal effectively . A failed air pressurization test during this time frame is not necessarily indicative of a bad joint. If replacing the gasket does not solve the issue, or the same joint routinely fails a pressurization test, conduct a formal root cause analysis with appropriate design groups.Approved Suppliers and Materials
Silicone
Table 2
Silicone Approved Suppliers and Materials Chart
Type Supplier Material
A Dow Corning Corporation
Midland, MI Silastic 732 RTV
(Order shall specify black in color)
Momentive Performance Materials
Waterford, NY RTV-103
Loctite Corporation
Rocky