{"product_id":"castair-float-switch-for-low-oil-control-only-6304b","title":"Castair Float Switch for Low Oil Control Only 6304B","description":"\u003ch2\u003eCastair Float Switch for Low Oil Control — Replacement Sensor Component (Part# 6304B)\u003c\/h2\u003e\n\n\u003cp\u003eThe Castair 6304B is the float switch sensor that is part of the 6304 low oil control system. If your low oil control unit is tripping or not detecting oil level correctly, and the wiring and control module check out, this float switch is the component to replace. It is the mechanical sensor — a float that rises and falls with crankcase oil level and triggers the protective switch when oil drops below the safe threshold.\u003c\/p\u003e\n\n\u003cp\u003eAt $40.81, the 6304B lets you replace the wear component of the low oil control system without replacing the entire assembly. That makes sense when the float or switch mechanism has failed but the mounting hardware and wiring are intact.\u003c\/p\u003e\n\n\u003ch3\u003eHow the Low Oil Control System Works\u003c\/h3\u003e\n\u003cp\u003eThe Castair low oil control system protects the compressor pump from running with insufficient lubrication. The system has two main components:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe float switch (6304B — this part):\u003c\/strong\u003e A mechanical float that sits in the crankcase. As oil level drops, the float drops with it. At the trip point, the float activates a switch that signals the control circuit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe control module (6304 or 6304M):\u003c\/strong\u003e Receives the signal from the float switch and either triggers an alarm or cuts power to the motor, depending on configuration.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThe 6304B is only the float switch — the sensor half of the system. It does not include the control module. If you need the complete system, see the 6304M (single unit, factory-mounted) or the 6304X2M (dual unit for duplex systems).\u003c\/p\u003e\n\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e 6304B\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eComponent:\u003c\/strong\u003e Float switch sensor (replacement component)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplication:\u003c\/strong\u003e Castair 6304 series low oil control systems\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFunction:\u003c\/strong\u003e Mechanical oil level detection, activates at low oil threshold\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrice:\u003c\/strong\u003e $40.81\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhen to Replace the Float Switch\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFloat switch is physically damaged:\u003c\/strong\u003e The float itself can develop cracks or become waterlogged with oil over time, causing it to sink even when oil level is correct. This triggers nuisance low-oil shutdowns.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSwitch mechanism has failed open or closed:\u003c\/strong\u003e If the low oil control never trips when it should, or trips constantly when oil level is correct, the float switch mechanism is the first thing to test and replace.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePreventive maintenance on high-hours compressors:\u003c\/strong\u003e On a compressor that has seen heavy use, replacing the float switch as part of a scheduled overhaul is inexpensive insurance.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAfter a low-oil event:\u003c\/strong\u003e If the compressor actually ran low on oil, inspect the float switch. A float switch that was submerged in sludge or debris may not function reliably afterward.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eDiagnosing Before You Order\u003c\/h3\u003e\n\u003cp\u003eBefore ordering the 6304B, do a quick check of the full low oil control circuit:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eVerify oil level is actually correct — confirm with the dipstick, not just the sight glass if one is present.\u003c\/li\u003e\n\u003cli\u003eCheck wiring from the float switch to the control module for damage, corrosion, or loose terminals.\u003c\/li\u003e\n\u003cli\u003eDisconnect the float switch and manually test continuity — with the float in the up position (normal oil level), the circuit should be in one state; with the float allowed to drop, it should switch.\u003c\/li\u003e\n\u003cli\u003eIf continuity behaves correctly during bench test but the system still trips, the problem is in the control module or wiring, not the float switch.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eIf you are unsure how to test the float switch on your specific Castair model, call us at 866-217-0063 before ordering — we can walk through the diagnostic with you.\u003c\/p\u003e\n\n\u003ch3\u003eParts Relationships — 6304 System Components\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e6304B (this part, $40.81):\u003c\/strong\u003e Float switch only — the sensor component\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e6304M ($147.95):\u003c\/strong\u003e Complete low oil control, single unit, factory-mount configuration\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e6304X2M ($296.25):\u003c\/strong\u003e Complete low oil control, dual unit, for duplex (two-pump) systems\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhy the Low Oil Control System Matters\u003c\/h3\u003e\n\u003cp\u003eA Castair compressor pump is a significant investment. The C-series and G-series industrial pumps are all cast iron, oil-lubricated, and built for long service life — but only if they have adequate lubrication. Running a compressor pump dry, even briefly, can score the cylinder walls, damage the connecting rod bearings, and seize the crankshaft. A replacement pump costs far more than this float switch. The low oil control system is a cheap insurance policy against an expensive failure.\u003c\/p\u003e\n\n\u003ch3\u003eWhy Buy From Air Compressor Factory Direct?\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCastair specialist:\u003c\/strong\u003e We carry the full 6304 system line — replacement float switches, complete single units, and duplex units.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFree shipping\u003c\/strong\u003e on qualifying orders.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFree technical support:\u003c\/strong\u003e Call 866-217-0063 if you need help diagnosing your low oil control system before ordering parts.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Castair components:\u003c\/strong\u003e The 6304B is a genuine Castair part — correct fit and function for 6304-series systems.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eCall 866-217-0063 for quick answers and help!\u003c\/strong\u003e\u003c\/p\u003e","brand":"Cast Air","offers":[{"title":"Default Title","offer_id":53342510514389,"sku":"6304B","price":75.26,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0622\/8466\/0949\/files\/HOUR-METER_e7618201-7eef-4f8e-92ce-8e4dc1a71aa9.jpg?v=1772652542","url":"https:\/\/aircompressorfactorydirect.com\/products\/castair-float-switch-for-low-oil-control-only-6304b","provider":"Air Compressor Factory Direct","version":"1.0","type":"link"}