ENGINE COOLING SYSTEM

Question 1

Types of common thermostat

Answer 1

1. Wax pellet thermostat
2. Bellows type

Question 2

Wax pellets thermostat

Answer 2

How it works: Uses a wax that expands when heated to push open the valve
Opens at set temp (like 82°C or 88°C) to let coolant flow
Reliable, simple, found in most cars and trucks

Question 3

Bellow types thermostat

Answer 3

this is a more specialized version of the wax-pellet thermostat. It’s often found in older vehicles, some heavy-duty applications, and certain performance engines.

Bellows Mechanism: This type uses a metal bellows (a flexible, expandable chamber) filled with a gas or liquid inside.
When the engine heats up, the fluid or gas inside the bellows expands, pushing a piston that opens the thermostat to allow coolant to flow.
The bellows are connected to a valve that regulates the flow of coolant, just like the wax-pellet version.