GM Metric Iron Caliper – Part No: 120-16101
Call (805) 388-1188
GM-Metric-Iron Single Piston Floater
Prod #: 120-16101
Price: $104.80

GM-Metric-Iron Single Piston Floater - Product Summary
Caliper No: 120-16101
GM-Metric-Iron Single Piston Floater

Piston Count 1
Piston Area (in²) 4.90
Piston Type Stainless
Dust Boot No
Rotor Dimensions
Rotor Width (in) 1.04
Rotor Diameter(in) 11.75
Pad Dimensions
Pad Area (in²) 8.7
Pad Volume (in³) 2.9
Duty Rating & Material
Material Cast Iron
Weight(Lbs) 4.3
Colors & Finish
Color Bare
Finish Bare

Mount Center(in) 5.46
Mount Position
Mount Side Universal
Mount Type Floating
UPC Number
UPC 889545084139
Product Documents
Product Data Sheet

Click To Download
Installation Instructions

D-154 Instructions Bleed Caliper
Click To Download

WARNING: Cancer and Reproductive Harm
Applicable to Brake Pads Only

120-16101 - Product Description

GM-Metric-Iron Single Piston Floater

These are all new and not rebuilt, cast iron calipers, purpose built for racing. Wilwood’s GM Metric Calipers are bolt-on replacements for 1978 and later GM Metric calipers widely used in "spec" racing categories. Wilwood’s new 2.50” piston GM Metric calipers are now officially approved for IMCA as OEM replacement caliper that meet all rules in Modified, Stock Cars, Hobby Stocks, Northern and Sothern Sport Mods. The GM Metric caliper is also available in 2.75” and 2.00” piston sizes for use in other non-restricted series or applications. Calipers require use of hardened Wilwood slide pins (sold separately), request part no. 230-0619 (slide pin kit) that contains 4 slide pins, enough for two calipers.

Wilwood iron GM Metric calipers combine new part quality with modern machining precision. There are three piston size options to assist builders with properly building static bias into a car. Previously, builders using the metric calipers generally had to mount the same size calipers on all four wheels. This drastically limited the tuning options and often created front to rear bias ratios that were not conducive to good handling and stability under hard braking. Some builders, and other brake suppliers, chose to offer re-machined OE calipers to provide a bias tuning option. Unfortunately, re-machining a used casting that was never designed for the larger bore size, can create real compromises in strength, reliability, and performance.

To address these needs, Wilwood has tooled three separate castings that are fitted with 2.75", 2.50” or 2.00" stainless steel pistons and high temperature bore seals. Each casting is designed specific for its intended bore size. The calipers are strong and precise, without unnecessary added weight from oversized castings. The stainless steel pistons resist corrosion while helping to slow the heat transfer from the pads. The high temperature seals provide long service life when used in hard braking applications and maintain their resilience to provide positive piston retraction on release.

Product Specifications

Rotor Compatibility
Rotor Width (in) 1.04
Maximum Rotor Width (in) 1.04
Minimum Rotor Width (in) 0.81
Maximum Rotor Diameter(in) 11.75
Minimum Rotor Diameter(in) 11.00

Brake Pad Specifications
Brake Pad Type 1 D154
Brake Pad Type 2 N-A
Brake Pad Type 3 N-A
Total Pad Area (in²) 8.7
Total Pad Volume (in³) 2.9
Piston Specifications
Piston 1 Bore (in) 2.50
Piston 2 Bore (in)
Piston 3 Bore (in)
Total Piston Area (in²) 4.90

Mounting Specifications
Mount Type Floating
Mount Side Universal
Mount Center(in) 5.46
Mount Hole Size(in) 0.69
Mount Height(in) 0.48
Inlet Thread Size M10 x 1.50
Pad Dimensions & Part Numbers
Pad Dimensions for the GM-Metric-Iron Single Piston Floater Pad Dimensions for the GM-Metric-Iron Single Piston Floater Zoom Image
Axle Set P/N
Pad Type
Non-Bedded Pads - by Compounds
PolyMatrix A
Mount Dimensions & Part Numbers

Dimensions for the GM-Metric-Iron Single Piston Floater Dimensions for the GM-Metric-Iron Single Piston Floater Zoom Image

Additional Notes

All Wilwood GM Metric Calipers use the standard D154 type brake pads. The complete range of Wilwood high performance and racing pad compounds is available to match response, friction, and temperature range to any application.

Parts & Accessories

O-Ring Kit 130-12084
Replacement Dust Boot N-A
Replacement Piston 1 200-11793
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 220-8932
Self Bleeder Tube N-A
Cross-Over Tube N-A

Additional related products:

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Version: 3.05 June 23, 2023