Piaggio B004742 Radiator Water Return Hose in Rubber – Porter Petrol, LPG, Methane and Diesel D120

The original Piaggio radiator water return hose, code B004742, is the rubber hose that returns coolant to the Porter's cooling system. It is S-shaped, with smooth ends to be secured with standard screw clamps (observed from product photographs), and has the production code stamped on its body. In the Porter, the radiator is at the front and the engine at the rear: the circuit is long, the hoses operate hot and stiffen with age — it is one of the parts that cracks first.

✓ Strengths

• Original Piaggio Group spare part, code B004742 — the shape is standard, not a universal hose to be cut to size
• Valid for the entire Porter range: petrol, LPG, methane, Maxxi, and D120 diesel, from 1992 to 2015
• Pre-formed S-curve: it slides in without forcing and without kinks, which are the hidden cause of half of all overheating issues
• Installation with screw clamps, standard ones: no quick connector, no special tools
• The twin delivery hose is the B004741: it is advisable to change them together
• New product, shipped by an official Piaggio and Aprilia dealer

Technical features

Vehicle compatibility

List taken from the official Piaggio Group spare parts catalog. If your trim level is not listed, please send us the chassis number: we will verify the exact code in the official catalog before you order.

Who it's perfect for

For those with a working Porter who have seen the temperature warning light come on, or found a green stain under the vehicle in the morning. A leaking hose is a minor repair that, if ignored, can turn into a head gasket issue: the engine overheats, the fluid level drops, and the cost increases by an order of magnitude. It is also the right replacement for those performing a thorough service on a twenty-year-old Porter and want to replace the entire water circuit with original parts instead of universal hoses and random clamps.

Frequently Asked Questions

How do I know if the hose needs changing?
When the engine is cold, squeeze it by hand: if it is hard and brittle, or conversely soft and spongy, it's worn out. Look for cracks on the curves and white or green stains near the clamps, which indicate even a minimal leak.

Is it suitable for both petrol and diesel?
Yes. The official catalog indicates this code for petrol, LPG, and methane Porters — standard and Maxxi — and for D120 diesel, standard and Maxxi.

Do I also need the delivery hose?
Not mandatory, but it's the twin: it's called B004741 and ages alongside this one. If the vehicle is many years old, changing them in pairs avoids having to do the job again in six months.

Are clamps included?
No, the price is for the hose only. They are standard screw clamps, available everywhere.

Does the shipment originate from Italy?
Yes. We ship from Cercola, in the province of Naples, with tracked courier service.