{"product_id":"castair-preventative-maintenance-kit-c11-air-end-for-5-15hp-rotary-compressors-mkg11","title":"Castair Preventative Maintenance Kit C11 Air End for 5-15HP Rotary Compressors MKG11","description":"\u003cp\u003eThe Castair MKG11 Preventative Maintenance Kit covers the G11 air end (also referenced as the C11 air end on some unit labels — both names refer to the same Castair air end platform) on 5–15HP rotary screw compressors. If your compressor is in the 5–15HP range and runs a Castair G11 or C11 air end, this is the correct PM kit. It ships as a complete service bundle: two air filters, four oil filters, one separator filter, and five gallons of CAST-LUBE synthetic oil. That is everything you need for one full service interval, matched to the G11 air end specs, at a 10% discount versus buying the same parts individually.\u003c\/p\u003e\n\n\u003ch3\u003eG11 vs. C11 Air End — Clarification\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSame air end, two names:\u003c\/strong\u003e Some Castair compressors in the 5–15HP range have unit plates and manuals that reference the \"C11\" air end. Castair''s official parts catalog lists this platform as the \"G11.\" If your compressor documentation says C11, the MKG11 kit is correct.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWhen to call us:\u003c\/strong\u003e If your unit plate shows a different air end designation entirely, call 866-217-0063 before ordering. We will confirm compatibility against your model number.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhy Buy a Kit Instead of Individual Filters\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e10% discount vs. individual parts:\u003c\/strong\u003e Buying filters and oil as a kit saves 10% compared to individual part orders. On a $628 purchase, that is meaningful savings per service cycle.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eComplete PM coverage in one order:\u003c\/strong\u003e Air filters, oil filters, separator, and oil — all in one shipment. No partial-service situations where you have everything except the separator.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCorrect dimensions guaranteed:\u003c\/strong\u003e The G11 air filter (RAFG11) has specific dimensions (ID: 2 5\/8\", OD: 3 7\/8\", HGT: 3 1\/8\") that are smaller than the D62 and G30 filters. Ordering the kit means you get the right size every time without cross-referencing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM oil included:\u003c\/strong\u003e CAST-LUBE is Castair''s own synthetic formulation for rotary screw air ends. The wrong oil in a rotary screw unit — wrong viscosity, wrong additive package — shortens air end life. Using CAST-LUBE removes that variable.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eKit Components\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAir Filters (qty 2):\u003c\/strong\u003e Part number RAFG11. Paper element. ID: 2 5\/8\", OD: 3 7\/8\", Height: 3 1\/8\". Sized for the G11 air end — notably smaller than the D62 (RAFD6-62) and G30 (32DP) filters. Do not substitute.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOil Filters (qty 4):\u003c\/strong\u003e Part number ROFD3-4-G11. Spin-on design. This filter is shared across several Castair air ends: D3, D31, D4, and G11. If you have other Castair units on the same platform, these filters will cross-service them as well.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeparator Filter (qty 1):\u003c\/strong\u003e Part number RSFLD3-4-6-G11-P75. Spin-on design. This separator is a multi-platform part — it fits D3, D31, D4, D6, P75, and G11 air ends. A shared separator means lower per-unit stocking cost if your shop runs multiple Castair platforms.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCAST-LUBE Synthetic Compressor Oil (5 gallons):\u003c\/strong\u003e Castair''s own synthetic oil formulated for rotary screw air ends. Provides oxidation resistance and thermal stability through normal operating cycles. Five gallons covers one oil change for a unit in this HP range.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eAir End Compatibility\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrimary fit:\u003c\/strong\u003e G11 air end (also labeled C11 on some units), 5–15HP rotary screw compressors\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHP range covered:\u003c\/strong\u003e 5HP, 7.5HP, 10HP, and 15HP Castair rotary screw models with G11\/C11 air end\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShared filter note:\u003c\/strong\u003e The oil filter (ROFD3-4-G11) and separator (RSFLD3-4-6-G11-P75) are used across the D3, D31, D4, D6, and P75 air ends as well. The air filter RAFG11 is G11-specific — do not use D62 or G30 air filters on a G11 unit.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat's in the Kit\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e2x Air Filter RAFG11 (G11 paper element, ID: 2 5\/8\", OD: 3 7\/8\", HGT: 3 1\/8\")\u003c\/li\u003e\n\u003cli\u003e4x Oil Filter ROFD3-4-G11 (spin-on, also fits D3\/D31\/D4)\u003c\/li\u003e\n\u003cli\u003e1x Separator Filter RSFLD3-4-6-G11-P75 (spin-on, multi-platform)\u003c\/li\u003e\n\u003cli\u003e5 gallons CAST-LUBE synthetic compressor oil\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eAvailable Castair Preventative Maintenance Kits\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMKP75 — P75 Air End, 5–15HP:\u003c\/strong\u003e Two air filters (20DP), four oil filters (ROFD62-P75), one separator (RSFLD3-4-6-G11-P75), five gallons CAST-LUBE. For P75 platform units in the 5–15HP range.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMKG11 — G11\/C11 Air End, 5–15HP (this kit):\u003c\/strong\u003e $628.47. For G11\/C11 platform units 5–15HP. Air filter RAFG11 is the distinguishing part — confirm your air end before ordering either MKP75 or MKG11.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMKD62 — D62 Air End, 15–25HP:\u003c\/strong\u003e $704.70. For mid-range 15–25HP units. Larger air filter (RAFD6-62, OD: 6 1\/8\") than the G11 kit. Step up if your unit is in the 15–25HP range.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMKG30R — G30 Air End, 15–30HP:\u003c\/strong\u003e For larger G30 platform units. Air filter 32DP (OD: 9 1\/4\") is substantially larger. For 15–30HP G30 units.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eAll four kits save 10% vs. individual parts. If you are unsure which air end your compressor has, call 866-217-0063 with your model number.\u003c\/p\u003e\n\n\u003ch3\u003eFilter Reference — G11 Air End Individual Parts\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAir Filter:\u003c\/strong\u003e RAFG11 — ID: 2 5\/8\", OD: 3 7\/8\", HGT: 3 1\/8\" — G11 paper element\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOil Filter:\u003c\/strong\u003e ROFD3-4-G11 — spin-on, also fits D3\/D31\/D4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeparator Filter:\u003c\/strong\u003e RSFLD3-4-6-G11-P75 — spin-on, fits D3\/D31\/D4\/D6\/P75\/G11\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOil:\u003c\/strong\u003e CAST-LUBE synthetic, available in 5-gallon jugs\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhen Does a Shop Need This Kit\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eYou have a 5–15HP Castair rotary screw unit with a G11 or C11 air end\u003c\/strong\u003e coming up on its service interval. The MKG11 is the correct PM kit — stock it and service on schedule.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eYou see \"C11\" on your unit plate:\u003c\/strong\u003e The MKG11 is the right kit. The C11 and G11 designations refer to the same air end. Call us if you want to confirm before ordering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eYou run a small shop compressor hard:\u003c\/strong\u003e A 10–15HP rotary screw running near-continuous duty cycles needs on-schedule PM to protect the air end. Having the kit on the shelf before you need it prevents emergency downtime.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eYou run multiple Castair units on the same platform:\u003c\/strong\u003e The oil filter and separator in this kit are shared across D3, D31, D4, D6, and P75 air ends. Stocking the MKG11 gives you filters that also cover other units in your shop.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStep up to MKD62 instead\u003c\/strong\u003e if your unit is a 15–25HP machine with a D62 air end. The D62 requires larger air filters — you cannot use RAFG11 on a D62. Confirm your air end before ordering.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStep up to MKG30R instead\u003c\/strong\u003e for 15–30HP G30 air end units. The G30 uses a significantly larger air filter (32DP) and different oil filter (ROFD16-G30).\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eKit Part Number:\u003c\/strong\u003e MKG11\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAir End:\u003c\/strong\u003e G11 (also labeled C11 on some unit nameplates)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHP Range:\u003c\/strong\u003e 5–15HP rotary screw compressors\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAir Filter P\/N:\u003c\/strong\u003e RAFG11\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAir Filter ID:\u003c\/strong\u003e 2 5\/8\"\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAir Filter OD:\u003c\/strong\u003e 3 7\/8\"\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAir Filter Height:\u003c\/strong\u003e 3 1\/8\"\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAir Filter Type:\u003c\/strong\u003e Paper element\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAir Filter Qty in Kit:\u003c\/strong\u003e 2\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOil Filter P\/N:\u003c\/strong\u003e ROFD3-4-G11\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOil Filter Type:\u003c\/strong\u003e Spin-on\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOil Filter Also Fits:\u003c\/strong\u003e D3, D31, D4 air ends\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOil Filter Qty in Kit:\u003c\/strong\u003e 4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeparator Filter P\/N:\u003c\/strong\u003e RSFLD3-4-6-G11-P75\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeparator Filter Type:\u003c\/strong\u003e Spin-on\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeparator Also Fits:\u003c\/strong\u003e D3, D31, D4, D6, P75 air ends\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeparator Filter Qty in Kit:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOil Type:\u003c\/strong\u003e CAST-LUBE synthetic compressor oil\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOil Qty in Kit:\u003c\/strong\u003e 5 gallons\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eKit Price:\u003c\/strong\u003e $628.47\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSavings vs. Individual Parts:\u003c\/strong\u003e 10%\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer:\u003c\/strong\u003e Castair (Cast Air)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhy Buy From Air Compressor Factory Direct?\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompressor parts specialists:\u003c\/strong\u003e We stock the full Castair maintenance kit lineup and know which kit matches which air end. The G11\/C11 naming issue is a common point of confusion — we can verify your unit before you order.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFree shipping:\u003c\/strong\u003e The MKG11 ships free. Five gallons of synthetic oil plus filters is not a light shipment — free shipping is real savings on parts orders of this type.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFree tech support:\u003c\/strong\u003e Call 866-217-0063 before ordering if you have any question about whether your unit has a G11\/C11 or a different air end. We confirm compatibility before you spend $628.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFull manufacturer warranty:\u003c\/strong\u003e Castair OEM parts with full Castair warranty coverage. No aftermarket substitutes.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHonest recommendations:\u003c\/strong\u003e If the MKG11 is not right for your machine, we will point you to the kit that is. We sell parts correctly the first time.\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":53342572118229,"sku":"MKG11","price":1158.72,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0622\/8466\/0949\/files\/parts6_11be6f4e-f136-4880-a2bb-e9672126e428.jpg?v=1772652743","url":"https:\/\/aircompressorfactorydirect.com\/products\/castair-preventative-maintenance-kit-c11-air-end-for-5-15hp-rotary-compressors-mkg11","provider":"Air Compressor Factory Direct","version":"1.0","type":"link"}