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Vehicle Info NeededSONNAXPART NUMBER: 852-28821-05K
Master Servo Piston Kit Sealing Ring Type
$8286
Ships on 09/08/2026
Lowest Price GuaranteeMaster Servo Piston Kits
Master Servo Piston KitSealing Ring Type Purple Anodized Cover
The kits feature the no leak dual O-ring servo using two O-ring seals for superior, positive sealing. In applications with a distorted bore or case flex, O-rings will conform to the bore surfaces, a feature not possible with metal sealing rings. Precise slip fit with apply pin further improves performance.
In addition, Sonnax master servo kits 28821-05K and 28821-08K are designed to replace the piston and cover and accept either two PTFE seal rings or two OE metal sealing rings. Made with the same high-quality billet aluminum as our dual O-ring servos, these servos will give you the positive apply needed in high pressure racing conditions.
- Cover Purple Anodized
- Pipe Plug
- Hex Head Bolts (3)
- O-Ring
- Gasket
- Servo Piston
- Seal Rings (2) PTFE
The kits feature the no leak dual O-ring servo using two O-ring seals for superior, positive sealing. In applications with a distorted bore or case flex, O-rings will conform to the bore surfaces, a feature not possible with metal sealing rings. Precise slip fit with apply pin further improves performance.
In addition, Sonnax master servo kits 28821-05K and 28821-08K are designed to replace the piston and cover and accept either two PTFE seal rings or two OE metal sealing rings. Made with the same high-quality billet aluminum as our dual O-ring servos, these servos will give you the positive apply needed in high pressure racing conditions.
- Better sealing with O-ring and gasket
- Direct replacement
- Fitting for pressure testing
- Stronger to handle higher pressure
Part TypeAutomatic Transmission Servo Piston
BrandSONNAX
Package Height3.1
Package Width4.6
Package Length5.2
Weight1.1 PG
Part CategoryReplacement Parts
Part FitmentSemi Universal
Vendor Part Number28821-05K
Package Qty1
Package TypeEA
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Some parts are not legal for use in California or other states with similar laws / regulations
