GMW GMW15024 PDF

These engine coolant hoses or assemblies incorporating these coolant hoses are intended to withstand the effects of circulating solutions containing corrosion inhibitors and glycols and operating under various pressure conditions at continuous operating temperatures from 40 °C to maximum temperatures ranging from 120 °C to150 °C, dependent on type.

The tube and cover stocks of these hoses shall be made from ethylene propylene diene monomer (EPDM) compounded and reinforced with appropriate yarn (as described in 1.1) to meet the requirements of this specification. The radial thickness of the lining shall be at least 50% of the total wall thickness. Cover may be perforated to facilitate degassing during manufacturing operations. Hose shall be black. Alternate reinforcement may be permitted with Engineering Source Approval, and this alternate reinforcement will be referenced as the approved reinforcement for that specific hose approval in MATSPC. Use of high tensile modulus, low elongation polyaramid materials (i.e., Technora, Kevlar, and Twaron) may not be suitable for heater hose part numbers which are formed with small bend radii and used for dynamic applications. For additional information or aid in selection of proper reinforcement materials for specific part numbers, contact the regional Materials Engineer. No Rubber Manufactures Association (RMA) defined colored tracer or other identifying thread shall be added to the reinforcement specified for the construction of the hose.

Material Description. Materials covered by this specification are divided into several types, defining the material content, construction, and performance limits of each specific type of hose. Types D, F, and G are considered preferred types which should be used for all production hose releases unless there is a specialized application requiring a unique hose construction. If there is a unique hose application for which one of the other types might be considered or required, contact the GM Materials Engineer to discuss the appropriate hose type that should be used.

Refer to Appendix D, Table D1 and Table D2 for requirements to Type A, Type B, and Type C for legacy and service usage.

Type D. EPDM coolant hose, sulphur cured utilizing aramid reinforcement, capable of operating to a maximum continuous temperature limit of +130 °C, and formulated to contain zero (0) weight percent thiuram, and a maximum of 0.04 weight percent thiocarbamates in the EPDM rubber stock for both hose tube and cover. 

Type E. EPDM coolant hose, peroxide cured utilizing aramid reinforcement, capable of operating to a maximum continuous temperature limit of +150 °C. A Dicumyl peroxide cure system may not be used for this hose. 

Type F: EPDM coolant hose, peroxide cured utilizing aramid reinforcement, capable of operating to a maximum continuous temperature limit of +150 °C, but having greater expansion under pressure than Type E. A Dicumyl peroxide cure system may not be used for this hose. 

Type G: EPDM coolant hose, peroxide cured utilizing aramid reinforcement, capable of operating to a maximum continuous temperature limit of +150 °C. A Dicumyl peroxide cure system may not be used for this hose.

Type H: EPDM coolant hose, peroxide cured utilizing Polyethylene Terephthalate (PET) reinforcement, capable of operating to a maximum continuous temperature limit of +120 °C. A Dicumyl peroxide cure system may not be used for this hose. 

Symbols. Not applicable.

Typical Applications. This specification covers the material requirements of ethylene propylene diene monomer (EPDM) engine coolant hose, both large diameter (radiator hose) and small diameter (heater hose). In addition, this specification covers the material requirements for engine coolant hose which is incorporated into crimped metal pipe and hose assemblies, or which is incorporated into molded branched hose assemblies. The performance requirements for engine coolant hose and assemblies incorporating engine coolant hose are defined by additional performance specifications.