The Castair MKP75 Preventative Maintenance Kit covers the P75 air end on 5–15HP rotary screw compressors. This is the entry-level PM kit in Castair''s maintenance kit lineup — the right service bundle for smaller rotary screw units running the P75 air end. Like all four Castair PM kits, it ships as a complete service package: two air filters (20DP), four oil filters (ROFD62-P75), one separator filter (RSFLD3-4-6-G11-P75), and five gallons of CAST-LUBE synthetic compressor oil. That covers one full service interval for a P75-equipped unit, at a 10% savings versus buying the same parts individually.
P75 Air End — Platform Context
- Air end designation: P75, used in Castair rotary screw compressors in the 5–15HP range
- HP range covered: 5HP, 7.5HP, 10HP, and 15HP Castair rotary screw models with P75 air end
- Same oil filter as D62: The MKP75 and MKD62 share the same oil filter part number — ROFD62-P75. That part number encompasses both air end platforms. The air filter (20DP for P75 vs. RAFD6-62 for D62) and separator (RSFLD3-4-6-G11-P75 vs. RSFD62) are different. Confirm your air end before ordering if your unit is near the 15HP boundary between these two kits.
- Shared separator with G11 kit: The separator filter (RSFLD3-4-6-G11-P75) in this kit is also used in the MKG11 kit and fits the D3, D31, D4, D6, G11, and P75 air ends. If you run multiple Castair platforms, this separator covers a broad range.
Why Buy a Kit Instead of Individual Filters
- 10% discount vs. individual parts: All four Castair PM kits are priced at 10% below individual part purchases. The savings accrue every service cycle — if you service your compressor on schedule (which you should), the kit pricing adds up.
- Complete service interval, one shipment: Two air filters, four oil filters, one separator, and five gallons of CAST-LUBE. Nothing to chase down separately, no partial-service situations.
- OEM parts, not aftermarket substitutes: Every filter in the MKP75 is a Castair-spec part matched to the P75 air end. Aftermarket rotary screw filters sometimes have dimensional differences that affect sealing — with an OEM kit, that variable is eliminated.
- Correct oil in the box: CAST-LUBE is Castair''s own synthetic formulation for rotary screw air ends. Running the wrong oil in a rotary screw — incorrect viscosity, incompatible additive package — accelerates bearing and rotor wear. The kit removes any ambiguity about which oil to use.
Kit Components
- Air Filters (qty 2): Part number 20DP. Sized for the P75 air end. The 20DP is the P75-specific air filter — do not substitute filters from the D62 (RAFD6-62) or G11 (RAFG11) kits, which have different dimensions and configurations.
- Oil Filters (qty 4): Part number ROFD62-P75. Spin-on design. Shared with the D62 air end — the same physical filter covers both the P75 and D62 platforms. Four filters in the kit supports one service interval.
- Separator Filter (qty 1): Part number RSFLD3-4-6-G11-P75. Spin-on design. A broadly-shared separator — compatible with D3, D31, D4, D6, G11, and P75 air ends. The separator removes entrained oil from compressed air downstream of the air end; replacing it on schedule prevents oil carry-over into your air lines and tools.
- CAST-LUBE Synthetic Compressor Oil (5 gallons): Castair''s own synthetic oil for rotary screw air ends. Provides oxidation and thermal stability through operating cycles. Five gallons covers one oil change for a unit in the 5–15HP range.
What's in the Kit
- 2x Air Filter 20DP (P75 air end)
- 4x Oil Filter ROFD62-P75 (spin-on, also fits D62 air end)
- 1x Separator Filter RSFLD3-4-6-G11-P75 (spin-on, multi-platform)
- 5 gallons CAST-LUBE synthetic compressor oil
Available Castair Preventative Maintenance Kits
- MKP75 — P75 Air End, 5–15HP (this kit): Two air filters (20DP), four oil filters (ROFD62-P75), one separator (RSFLD3-4-6-G11-P75), five gallons CAST-LUBE. Entry-level PM kit for smaller Castair rotary screw units.
- MKG11 — G11/C11 Air End, 5–15HP: $628.47. Two air filters (RAFG11, ID: 2 5/8", OD: 3 7/8", HGT: 3 1/8"), four oil filters (ROFD3-4-G11), one separator (RSFLD3-4-6-G11-P75), five gallons CAST-LUBE. For G11/C11 platform units. Shares the separator with MKP75 but uses different air and oil filters.
- MKD62 — D62 Air End, 15–25HP: $704.70. Two air filters (RAFD6-62, ID: 4 3/4", OD: 6 1/8", HGT: 2 7/8"), four oil filters (ROFD62-P75 — same as MKP75), one separator (RSFD62 — different from MKP75), five gallons CAST-LUBE. For mid-range 15–25HP units. Shares the oil filter with MKP75 but uses a different air filter and D62-specific separator.
- MKG30R — G30 Air End, 15–30HP: Two air filters (32DP, ID: 5 3/4", OD: 9 1/4", HGT: 5 3/16"), four oil filters (ROFD16-G30), one separator (RSFD10-16-G30), five gallons CAST-LUBE. Largest PM kit in the lineup, for 15–30HP G30 platform units.
All four kits save 10% vs. individual parts. If you are not certain which air end your compressor has, call 866-217-0063 with your model number before ordering.
Filter Reference — P75 Air End Individual Parts
- Air Filter: 20DP — P75 air end specific
- Oil Filter: ROFD62-P75 — spin-on, also fits D62 air end
- Separator Filter: RSFLD3-4-6-G11-P75 — spin-on, fits D3/D31/D4/D6/G11/P75
- Oil: CAST-LUBE synthetic, available in 5-gallon jugs
When Does a Shop Need This Kit
- You have a 5–15HP Castair rotary screw unit with a P75 air end coming up on its service interval. This is the correct PM kit. The 20DP air filter is P75-specific — do not use a different kit''s air filter on a P75 unit.
- You are setting up a PM program for a small shop compressor: A 5–15HP rotary screw is often a shop''s primary or only air source. Scheduled PM prevents the kind of filter neglect that leads to oil carryover, dirty air, and accelerated air end wear. The MKP75 makes it easy to have everything ready when service is due.
- You run both P75 and D62 units: The oil filter (ROFD62-P75) in this kit is shared with the D62 platform. If you have both P75 and D62 units, you can stock the oil filters from either kit to cover both machines. The air filters and separators are different — those stay platform-specific.
- You run multiple Castair platforms and want to minimize separator SKUs: The separator (RSFLD3-4-6-G11-P75) in this kit covers D3, D31, D4, D6, G11, and P75 air ends. If your shop has a mix of smaller Castair units, this separator is a useful common stocking part.
- Step up to MKD62 instead if your unit is a 15–25HP machine with a D62 air end. D62 and P75 share an oil filter but have different air filters and separators — the kits are not interchangeable at the air filter level.
- Step up to MKG30R instead for 15–30HP G30 air end units. The G30 uses significantly larger filters across the board — nothing from the MKP75 kit carries over to a G30 unit.
- If you are unsure whether your unit has a P75 or G11 air end: Both are 5–15HP platforms with different filter requirements. The air filters are different (20DP for P75, RAFG11 for G11). Call 866-217-0063 with your model number and we will confirm which kit is correct.
Technical Specifications
- Kit Part Number: MKP75
- Air End: P75
- HP Range: 5–15HP rotary screw compressors
- Air Filter P/N: 20DP
- Air Filter Type: P75 air end specific
- Air Filter Qty in Kit: 2
- Oil Filter P/N: ROFD62-P75
- Oil Filter Type: Spin-on
- Oil Filter Also Fits: D62 air end
- Oil Filter Qty in Kit: 4
- Separator Filter P/N: RSFLD3-4-6-G11-P75
- Separator Filter Type: Spin-on
- Separator Also Fits: D3, D31, D4, D6, G11 air ends
- Separator Filter Qty in Kit: 1
- Oil Type: CAST-LUBE synthetic compressor oil
- Oil Qty in Kit: 5 gallons
- Savings vs. Individual Parts: 10%
- Manufacturer: Castair (Cast Air)
Why Buy From Air Compressor Factory Direct?
- Compressor parts specialists: The P75 and G11 kits are both 5–15HP kits and easy to mix up if you do not know your air end designation. We know which kit matches which Castair air end, and we confirm compatibility before the order ships.
- Free shipping: The MKP75 ships free. Five gallons of synthetic oil plus multiple filters is not a lightweight order — free shipping is meaningful on parts purchases of this type.
- Free tech support: Call 866-217-0063 before ordering if you are not certain whether your unit has a P75, G11, or D62 air end. We will confirm the correct PM kit for your specific compressor before you spend money on the wrong parts.
- Full manufacturer warranty: Castair OEM filters and oil carry the full Castair warranty. No aftermarket substitutes, no gray-market parts.
- Honest recommendations: If the MKP75 is not the right kit for your machine, we will tell you which one is. We do not sell kits that do not fit your equipment.
Call 866-217-0063 for quick answers and help!
