Piaggio 877528 Water Pump Cover – Beverly, Carnaby, MP3, X7, X Evo, Vespa GTS and GTV, Aprilia and Gilera

The Piaggio 877528 water pump cover is the die-cast aluminum casing that encloses the water pump impeller and houses the three connections of the cooling circuit. It is the original Piaggio spare part for all liquid-cooled Quasar and Leader 125-310 4T engines: a single code covering Beverly, Carnaby, MP3, X7, X8, X9, X10, X Evo, Vespa GTS and GTV, Aprilia Atlantic and Sport City, Gilera Nexus and Scarabeo Light.

✓ Strengths

• Original Piaggio spare part: the part is stamped with the casting reference 846734, the other number under which this cover appears in the catalog (observed from product photos)
• Raw die-cast aluminum, like the original equipment part: dissipates heat and does not deform with thermal cycles (observed from product photos)
• Three fittings already assembled: two directly integrated into the aluminum casting and the third in brass, screwed in — it arrives complete, no need to transfer anything from the old one (observed from product photos)
• Internal volute and sealing surface already machined, with three bushed screw seats (observed from product photos)
• This is the part replaced when fluid leaks from the engine: internal corrosion of the cover is one of the two most common causes, along with pump seal failure
• A single code for 39 model families across five brands, from 2005 to 2027: practically the entire liquid-cooled production of the group

Technical specifications

The features indicated as observed from the photographs derive from direct examination of the part in stock. Catalog data may be updated by Piaggio without prior notice.

Vehicle compatibility

This code covers 39 model families and 164 versions across five Piaggio Group brands, from 2005 to 2027.

Compatibility list from official Piaggio spare parts catalog: 5 brands, 39 families, 164 versions, detailed version by version in the product's technical sheet. Also covers Vespa GTS and GTV currently in production. If your model does not appear in the table, contact us for more information before ordering: we will check the catalog for you.

If your scooter is leaking coolant from the pump area, this is the first part to check. It costs little compared to the damage it prevents: an engine running without coolant will destroy the cylinder head and cylinder in a few kilometers. We ship in 24/48 hours from Cercola. If you also want the gasket or pump overhaul kit for your model, contact us for more information: we will combine them in the same order.

Who it's perfect for

• Anyone who finds coolant under the scooter or pink/green stains on the engine casing
• Anyone who has a corroded or punctured cover from the inside: this happens when the fluid is not replaced and loses its anti-corrosive properties
• Anyone doing a water pump overhaul kit and also wants to replace the cover with a new one
• Anyone who has broken a fitting while removing hoses hardened by age — here the three fittings come already assembled
• Workshops working on Quasar and Leader engines: a single code for 39 families is a part to keep on the shelf

Frequently asked questions

Is the gasket included?
No, it's a separate spare part, and it should always be replaced. Reassembling the new cover with the old gasket is the number one cause of "I changed it and it's still leaking." Contact us for more information with your model and year, and we'll tell you the correct code.

Are the fittings already there?
Yes, all three: two are integrated into the aluminum casting, the third is in brass and is already screwed in place (observed from product photos). You don't need to remove anything from the old cover.

I'm losing fluid: is changing the cover enough?
It depends on where it's leaking from. If it's dripping from the sealing surface, often yes (cover + gasket). If it's coming out of the small bleed hole under the pump, the mechanical seal has failed and a pump overhaul kit is needed. If there's play on the impeller shaft, it's the bearing. Disassemble and check before ordering only the cover.

My parts dealer gave me code 846734: is it the same?
Yes. 846734 is stamped on the part itself (observed from product photos): it's the same water pump cover as code 877528. It's normal to find both numbers depending on the exploded view consulted.

Is it the same part for a 2010 Vespa GTS 300 and a 2026 GTS 310?
Yes. The Piaggio Group has maintained the same water pump architecture on liquid-cooled Quasar and Leader engines for twenty years. That's why this code covers 164 versions: the scooter around it changes, not the pump.

What tightening torque should I use?
These are small screws in aluminum on aluminum: tighten them criss-cross and gently. Tightening them by feel is the most common way to deform the surface and end up with a worse leak than before. If you don't have a torque wrench, have the tightening done at a workshop.

Do I need to do anything after installation?
Yes: refill the fluid and bleed the air. On these engines, a bubble in the circuit will cause the temperature to rise even with the expansion tank at the correct level. Run the engine with the tank open until it stops gurgling, then refill.