The Wabco air brake chamber 9253921080 or 925-392-108-0 is a Type 30/30 combination spring brake unit designed for cam-operated drum brake systems. It carries a maximum operating pressure of 145.0 psi and a release pressure of 66.72 psi, with a stroke of 2.99 in. and a push-rod length of 3.55 in. The total length measures 14.29 in., bolt spacing is 4.75 in., and bolt threads are 5/8″-11 UNC. Two 3/8″-18 NPTF ports are provided at a 20-degree angle. The chamber is rated for -40C to +80C operation and is supplied without a boot. Call us to confirm proper fit for your application.Interchanges:WAB9253921080FeaturesType 30/30 combination spring brake chamber for cam-operated drum brake systemsMaximum operating pressure 145.0 psi; release pressure 66.72 psiStroke 2.99 in.; push-rod length 3.55 in.; total length 14.29 in.Bolt threads 5/8″-11 UNC; distance between bolts 4.75 in.Two 3/8″-18 NPTF ports positioned at a 20-degree angleOperating temperature range -40C to +80C; supplied without bootTech SpecsBrand: WABCOPart Number: 9253921080 or 925-392-108-0Type: 30/30 Combination Spring BrakeType of Operation: CamBrake Type: DrumStroke: 2.99 in.Push-Rod Length: 3.55 in.Total Length: 14.29 in.Max. Operating Pressure: 145.0 psiRelease Pressure: 66.72 psiBolt Threads: 5/8″-11 UNCBolt Length: 1.50 in.Distance Between Bolts: 4.75 in.Clevis Pin: 0.51 in.Port 1 Thread: 3/8″-18 NPTFPort 2 Thread: 3/8″-18 NPTFPort Angle: 20 degreesTemperature Range: -40C to +80CVersion: Without BootTechnical Specification: OE Specification