Brake Wheel Cylinder NM1646 | Fits Ford Galaxie, LTD, Lincoln Continental | XUI1997A

CM246

Technical Specifications Table

Parameter	Detail
Part Number	XUI1997A
Bore Diameter	25.40 mm
Mounting Size	Φ37.5 / 81.5 / 2×Φ10.5 mm
Thread Options	1/2-20 UNF · M10×1.0 · 3/8-24 UNF
Internal Reference	CM246
Position	Rear
Brake Type	Drum Brake

OE Cross Reference Coverage Table

Source	Number
OEN	M1646
OE	5472973
Ford OE	C7VY-2140-A
Ford OE	C8AZ-2140-C
Ford OE	C9AZ-2140-A
Dorman	M71245

Supplementary Description
These OE and aftermarket references appear across restoration parts catalogs, warehouse distributor databases, and classic Ford-Mercury-Lincoln inventory systems. When matching stock or confirming compatibility, any of the numbers above can be used to locate or verify this part. Buyers sourcing against Dorman M71245 or the C-series Ford OE numbers will find this a direct match on bore diameter and mounting dimensions.

Target Buyer Matching Table

Buyer Type	Fit & Advantage
Private Label Brands	OEM/ODM available — custom packaging and branding supported
Wholesale Distributors	Multi-OE cross-reference makes catalog matching straightforward
Classic Car Parts Retailers	One SKU covers 14 vehicle variants across three American brands
Cost-Focused Importers	Competitive alternative to Dorman M71245 and OE-priced stock

 

What Is a Brake Wheel Cylinder?
The brake wheel cylinder is a small but critical part inside a rear drum brake system. When you press the brake pedal, brake fluid travels through the lines and pushes into this cylinder. The cylinder then extends outward, pressing the brake shoes against the drum to slow the vehicle down.
This part — XUI1997A — is built for a specific group of American full-size cars from the late 1960s and early 1970s. These vehicles ran drum brakes at the rear as standard, and keeping those brakes working properly depends entirely on a functioning wheel cylinder.
A leaking or worn cylinder shows up as: fluid spots behind the rear wheels, a brake pedal that sinks lower than usual, or the car pulling to one side when braking. It's a safety-critical part, and a direct-fit replacement like this one keeps the repair simple and clean.

Thread Configuration Note
The XUI1997A platform is produced with thread configurations matching the OE references listed above — covering 1/2-20 UNF, M10×1.0, and 3/8-24 UNF. Different model years and body styles across this Ford-Mercury-Lincoln group used varying brake line fittings at the factory. Stocking against multiple OE numbers becomes simpler when the thread specs are already mapped to the original fitment data.

Classic car restoration remains an active market in North America, Australia, and parts of Europe. Ford and Lincoln platforms from this era — Galaxie, Continental, Marquis — have dedicated owner communities and specialist shops that need a consistent, affordable source for these exact components. Demand for these SKUs is niche but steady, and they're rarely well-served by mass-market suppliers. That gap is where catalog-focused distributors tend to hold margin.

Q: Is this a direct replacement for Dorman M71245?
Yes — same bore diameter, same mounting dimensions, direct swap.

Q: Is this for the rear brake assembly?
Yes. This wheel cylinder is designed for the rear drum brake assembly used on the listed applications. Always verify against your specific vehicle's brake configuration before ordering.

Q: Why do the OE references show different thread sizes?
Different model years and body types in this platform group used different brake line fittings at the factory. The XUI1997A is produced to match those OE thread specs — 1/2-20 UNF, M10×1.0, and 3/8-24 UNF — as documented in the original fitment references.