Brake Wheel Cylinder 22.22mm for Renault Laguna I Grandtour – XUI2821A

CM246

Technical Specifications

Parameter	Detail
Part Number	XUI2821A
Bore Diameter	22.22 mm
Mounting Size	Φ32 / 32 / 2×M6×1
Connecting Thread	M10×1.0 · M7×1
Position	Rear
Brake Type	Drum Brake

OE Cross Reference

Source	Number
Renault OE	7701042416
OE	6035390
OE	CR.633

Supplementary Description
Three references, all pointing to the same application. The 7701042416 is the primary Renault OE number for this fitment and the most commonly used reference in European parts databases. The 6035390 appears in broader aftermarket catalog systems. CR.633 is a supplier-side reference used in trade catalogs across France, Spain, and Germany.

Rear Drum Brakes on the Laguna I Grandtour — What You're Actually Replacing
The Renault Laguna I Grandtour used a mixed brake setup: disc brakes at the front, drum brakes at the rear. The wheel cylinder sits inside the rear drum assembly. When the brake pedal is pressed, hydraulic pressure forces two pistons outward from the center of the cylinder, pushing the brake shoes against the inside of the drum to slow the car down.
Over time, the cylinder's internal seals deteriorate. Brake fluid starts to seep past them, leaving traces on the backing plate or inside the wheel. When that happens, the rear brakes lose clamping force — sometimes gradually, sometimes more suddenly under hard braking. On a loaded estate car carrying passengers and luggage, that's not a minor issue.
XUI2821A is machined to the 22.22mm OE bore specification for this application. The mounting pattern — Φ32/32, 2×M6×1 — is specific to the Laguna I Grandtour. It differs from other Renault applications of the same era, which is why confirming the exact part number matters before ordering.

The Laguna I Grandtour — A Narrow Fitment With Consistent Demand
The Renault Laguna I Grandtour (K56_) is the estate body variant of the first-generation Laguna. It was produced from 1995 to 2001 and sold in significant volumes across France, the UK, Germany, Belgium, and the Netherlands. The Grandtour was the practical choice in the Laguna range — more boot space, used heavily as a family car and light load carrier.
Vehicles from this era are now over 20 years old. The ones still on the road tend to be in the hands of owners who maintain them, or in smaller fleets in Eastern Europe where older French cars remain common daily drivers. Parts availability for the Laguna I is narrower than for current platforms — most mainstream distributors have dropped these SKUs from active stock. That gap is exactly where specialist suppliers and niche catalog distributors operate.
The rear wheel cylinder on this car is not a high-frequency repair — but when it fails, finding the right part at short notice can be difficult. A shop with one in stock closes the job same day. A shop without one loses the vehicle for days while sourcing. Fleet and independent workshop buyers in markets where Laguna I cars are still serviced understand this problem well.
This is not a volume SKU in the way a Kangoo or Vivaro part would be. But it fits a sourcing gap that larger distributors have quietly stepped away from, which is why specialty aftermarket suppliers and trade catalog operators continue to carry it.

Q1: Is the mounting size on XUI2821A the same as other 22.22mm Renault wheel cylinders?
No. The Laguna I Grandtour uses a Φ32/32 mounting pattern with M6×1 bolts. Other Renault applications of the same bore — including the Kangoo — use a different mounting size. Always confirm the full part number before substituting.

Q2: Does this fit the standard Laguna I hatchback or sedan?
This part is listed for the Grandtour (K56_) estate body only. The hatchback and saloon variants may use a different rear brake configuration. Verify against your specific vehicle's OE number before ordering.

Q3: Is this supplied as a single unit or a pair?
Single cylinder per unit. Rear drum brake service is generally done in pairs — order two per axle for a complete repair.

Q4: What is the connecting thread specification?
M10×1.0 for the brake line connection and M7×1 for the secondary port. Both are standard Renault metric fittings for this era.

Q5: Are parts for the Laguna I still available from main distributors?
Mainstream catalog coverage for Laguna I has thinned considerably. This is one of the reasons specialist and trade-only suppliers remain the more reliable source for this application.