GM Single Piston Caliper – Part No: 120-5289
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GM III Single Piston Floater
Prod #: 120-5289
Price: $142.44

GM III Single Piston Floater - Product Summary
Caliper No: 120-5289
GM III Single Piston Floater

Piston Count 1
Piston Area (in²) 5.94
Piston Type Stainless
Dust Boot No
Rotor Dimensions
Rotor Width (in) 1.25
Rotor Diameter(in) 11.75
Pad Dimensions
Pad Area (in²) 10
Pad Volume (in³) 3.9
Duty Rating & Material
Material Cast Aluminium
Weight(Lbs) 3.7
Colors & Finish
Color Anodize
Finish Type III Anodize

Mount Center(in) 7.06
Mount Position
Mount Side Universal
Mount Type Floating
UPC Number
UPC 889545004069
Product Documents
Product Data Sheet

Click To Download
Installation Instructions

WARNING: Cancer and Reproductive Harm
Applicable to Brake Pads Only

120-5289 - Product Description

GM III Single Piston Floater

Wilwood’s GMIII caliper represents the latest refinements in caliper design and manufacturing through solid modeling and stress simulation programs. The result is the most rigid, highest torque, lightweight aluminum caliper with weights starting at 3.36 pounds. Requires use of hardened Wilwood slide pins (sold separately), request part no. 230-0619 (slide pin kit) contains 4 slide pins, enough for two calipers

The real strength comes from its exclusive triple bridge configuration which provides a tremendous increase in clamping force over other twin bridge calipers. Efficient­ designs further maximize weight savings: material is properly placed to fortify all load bearing points. Each caliper model has its own unique casting: 2.38” diameter piston calipers incorporate a smaller external contour than the larger 2.75” diameter piston calipers. Any material that did not contribute to strength, was eliminated for weight reduction.

The GMIII?incorporates standard Wilwood features like stainless steel pistons for increased fluid protection and high temperature seals for controlled retraction which provides improved driver feel. The GM III for 1.00” width rotor is machined and fitted with OEM type slide pin vibration dampeners for a direct OEM caliper interchange.

Vehicle Applications
Driving Environment Street Rods
Vehicle Sub-Types
Application Duty Heavy Duty
Driving Environment Street Performance
Vehicle Sub-Types Domestic
Application Duty Heavy Duty
Driving Environment Street Performance
Vehicle Sub-Types Import
Application Duty Heavy Duty
Driving Environment Late Model Asphalt
Vehicle Sub-Types ASA, All Pro, SW Tour, etc...
Application Duty Medium Duty
Driving Environment Drag Racing
Vehicle Sub-Types
Application Duty Heavy Duty
Driving Environment Off Road
Vehicle Sub-Types
Application Duty Medium Duty

Product Specifications

Rotor Compatibility
Rotor Width (in) 1.25
Maximum Rotor Width (in) 1.25
Minimum Rotor Width (in) 1.19
Maximum Rotor Diameter(in) 11.75
Minimum Rotor Diameter(in) 11.00

Brake Pad Specifications
Brake Pad Type 1 D52
Brake Pad Type 2 N-A
Brake Pad Type 3 N-A
Total Pad Area (in²) 10
Total Pad Volume (in³) 3.9
Piston Specifications
Piston 1 Bore (in) 2.75
Piston 2 Bore (in)
Piston 3 Bore (in)
Total Piston Area (in²) 5.94

Mounting Specifications
Mount Type Floating
Mount Side Universal
Mount Center(in) 7.06
Mount Hole Size(in) 0.69
Mount Height(in) 0.77
Inlet Thread Size 1/8-27 NPT
Pad Dimensions & Part Numbers
Pad Dimensions for the GM III Single Piston Floater Pad Dimensions for the GM III Single Piston Floater Zoom Image
Axle Set P/N
Pad Type
Non-Bedded Pads - by Compounds
Mount Dimensions & Part Numbers

Dimensions for the GM III Single Piston Floater Dimensions for the GM III Single Piston Floater Zoom Image

Additional Notes

These tight grained, high density aircraft alloy aluminum castings are fully machined, assembled and tested in-house by fully trained technicians at Wilwood to assure top quality and peak performance.

Parts & Accessories

O-Ring Kit 130-4955
Replacement Dust Boot N-A
Replacement Piston 1 200-6633
Replacement Piston 2 N-A
Replacement Piston 3 N-A
Replacement Piston 4 N-A
Cross-Over O-Ring Kit N-A
Bridge Bolt Kit N-A
Wear Plate L/H N-A
Wear Plate R/H N-A
Pad Retainer N-A
Bleed Screw Kit 220-0627
Self Bleeder Tube N-A
Cross-Over Tube N-A
Products commonly used with this item:

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All images shown are for illustrative purposes only. Actual product received may be different than what is portrayed on the web site.
Wilwood makes every effort to maintain our web site to ensure the accuracy of prices and product information. However, product information and prices are subject to change without notice. Please call (805) 388-1188 before ordering to verify current prices and product information.
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Version: 3.05 June 23, 2023