Description / Abstract: Material Description. This specification covers the requirements of silicone elastomer coolant hoses in four (4) classes of straight and formed coolant hose intended for use as radiator hose, heater hose and other flexible conduits for automotive engine cooling systems. Such products are intended to withstand the effects of circulating solutions containing glycols, small amounts of corrosion inhibitors and soluble oils, and operating under various pressure conditions at temperatures from -55 °C to +200 °C, and to withstand higher temperature environment than hoses covered by Ethylene Propylene Diene Monomer (EPDM) in GMW15024.

Class I, Class II and Class III. The tube and cover stocks of the hose shall be made from polysiloxane (silicone rubber) compound capable of operating to a maximum continuous temperature limit of +175 °C. The tube and cover compounds shall meet the requirements of Table 1. The cover shall be black. 1.1.2 Class IV: The tube and cover stocks of the hose shall be made from polysiloxane (silicone rubber) compound capable of operating to a maximum continuous temperature limit of +200 °C with +250 °C excursion temperature. The tube and cover compounds shall meet the requirements of Table 1. The cover shall be black.

The hoses shall be reinforced with a high temperature resistant vendee approved fiber construction. Class I shall be of wrapped plies of fabric to meet the requirements of Table 4. Class II, Class III and Class IV shall be of knitted, braided, or spiral construction to meet the requirements of Table 3 and Table 4.

Dimensions and Tolerances. Unless otherwise specified on the engineering drawing, dimensions and tolerances, inner diameter (ID), wall thickness, length and curved hose arm length for Class I hose, shall conform to those published in SAE J20, and Class II, Class III and Class IV hoses shall conform to those published in SAE J20 and SAE J30.