{"product_id":"cold-start-auxiliary-unloader-valve-air-compressor","title":"Cold Start Auxiliary Unloader Valve for Air Compressors, 1\/8 and 1\/4 in","description":"\u003cp\u003eA cold start auxiliary unloader bleeds the pressure trapped between the pump and the check valve so the compressor starts against no load. It is the part that decides whether a cold compressor spins up or just sits there humming and tripping the overload.\u003c\/p\u003e\n\u003cp\u003eOn a cold morning the oil in the crankcase is thick, the motor is at its weakest, and any residual head pressure is working against it. An auxiliary unloader takes that pressure out of the equation.\u003c\/p\u003e\n\u003ch3\u003eSizes\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eS1005:\u003c\/strong\u003e cold start auxiliary unloader, 1\/8 in, reference AU100\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eS1006:\u003c\/strong\u003e cold start auxiliary unloader, 1\/4 in, reference AU200\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWhen you need one\u003c\/h3\u003e\n\u003cp\u003eThe classic symptom is a compressor that starts fine when warm and will not start when cold, or one that trips its overload or pops a breaker on the first start of the day. Single phase motors are the usual sufferers because they have the least starting torque of anything you will find on a compressor. Before blaming the motor or the starter, check whether the machine is unloading properly at shutdown.\u003c\/p\u003e\n\u003ch3\u003eChoosing the size\u003c\/h3\u003e\n\u003cp\u003eMatch the port on the discharge tube or head where the unloader goes. 1\/8 in is the common size on smaller single stage pumps, 1\/4 in on larger ones. If the existing fitting has been bushed down at some point, measure the thread rather than trusting what is in it now.\u003c\/p\u003e\n\u003ch3\u003eRelated parts\u003c\/h3\u003e\n\u003cp\u003eAn unloader works with the pressure switch unloader and the discharge check valve. If the compressor is not unloading, all three are worth checking. We also stock Lefoo pressure switches with unloader, CDI pilot valves, and horizontal inline, vertical and in tank check valves in sizes from 1\/4 in to 2 in.\u003c\/p\u003e\n\u003ch3\u003eQuestions\u003c\/h3\u003e\n\u003cp\u003eTell us the compressor make, model and port size and the Warthog Air Compressor Store team will confirm the right valve before you order.\u003c\/p\u003e\n\u003cp\u003eCold start auxiliary unloader valves for air compressors in 1\/8 in and 1\/4 in, releasing trapped head pressure so the motor starts unloaded.\u003c\/p\u003e","brand":"AirComParts","offers":[{"title":"1\/8 in - AU100","offer_id":67721350250771,"sku":"S1005","price":5.49,"currency_code":"USD","in_stock":true},{"title":"1\/4 in - AU200","offer_id":67721350283539,"sku":"S1006","price":5.99,"currency_code":"USD","in_stock":true}],"url":"https:\/\/aircompressorstore.com\/products\/cold-start-auxiliary-unloader-valve-air-compressor","provider":"Warthog Air Compressor Store","version":"1.0","type":"link"}