Brake Wheel Cylinder 23.81mm for Renault Trafic & Opel Arena Van – XUI2832A

23.81mm — Why Bore Diameter Is the First Thing to Check
XUI2832A runs a 23.81mm bore — larger than the 22.22mm cylinders used across many other French van platforms from the same era. The difference is small in absolute terms, but it matters. A larger bore generates more hydraulic force output for the same pedal input, which suits heavier commercial vehicles where rear brake loading is higher. Fitting a 22.22mm cylinder in place of a 23.81mm unit reduces rear braking force, affects the front-to-rear brake balance, and creates a safety issue that may not be immediately obvious during a test drive.
For catalog buyers, this is worth flagging in product listings. Both bore sizes appear across Renault and Opel van platforms from this period, and the risk of substitution errors is real when buyers are sourcing by vehicle model rather than by confirmed OE number.

Two Brands, One Platform Connection
The Opel Arena and Renault Trafic share more than just a wheel cylinder. The Arena was built on the second-generation Trafic platform under a joint production agreement between Renault and General Motors. Opel badged and sold the vehicle across European markets from 1997 to 2001, while Renault continued the first-generation Trafic independently through the 1980s.
The result is a parts crossover that experienced buyers recognize immediately. A distributor stocking XUI2832A for Renault Trafic customers is automatically covered for Opel Arena enquiries as well. That dual coverage is one of the more useful characteristics of this SKU from a catalog management perspective — one line item handles two brand trees without any additional stock requirement.
Workshops in Southern Europe and North Africa that service older commercial fleets regularly encounter both models. The Trafic T-series was exported heavily to those markets in the 1980s and remained in working use well into the 1990s and beyond. Arena vans followed a similar trajectory after production ended in 2001.

Q1: What bore diameter does XUI2832A use, and how does it differ from similar Renault cylinders?
23.81mm. Most other Renault and Citroën van cylinders from this era use 22.22mm. The 23.81mm bore is specific to the Trafic T-series and Arena platform. Substituting the wrong bore size affects rear braking force and is not safe.

Q2: Both connecting ports are M10×1.0 — is that correct?
Yes. Unlike many other Renault wheel cylinders that combine M10×1.0 and M7×1 ports, XUI2832A uses M10×1.0 on both connections. This is consistent with the OE specification for this platform. Confirm against the vehicle's existing fittings before ordering.

Q3: Why does Renault have four separate OE numbers for the same part?
Renault updated part numbers across the Trafic T-series production run as component suppliers changed. The fitment remained the same across those updates. All four Renault OE numbers — 7701025172, 7701025934, 7701025935, and 7701034172 — cross to the same cylinder.

Q4: Does XUI2832A cover all four Trafic T-series body codes (T1, T2, T3, T4)?
Yes. All four body code variants of the Renault Trafic Box from 1980 to 1989 are confirmed fitments for XUI2832A.

Q5: Is this the same cylinder used on the Renault Trafic second generation?
No. The second-generation Trafic (from 2001 onward) uses a different brake specification. XUI2832A covers the first-generation T-series only (1980–1989).