What size is the coolant bleeder screw?
There isn’t a single universal size for coolant bleeder screws. The correct size depends on the specific vehicle, engine design, and the housing into which the screw is threaded. In practice, many bleeder screws use small metric or imperial threads, but you should confirm the exact size for your car in the manual or by inspecting the original screw.
Bleeder screws are tiny fasteners used to vent air from the cooling system and are typically located on the thermostat housing, near the radiator end tanks, or at heater core connections. Because the drainage and venting function is standardized in purpose but not in hardware across makes and models, the precise thread size and length can vary widely.
Common thread sizes you may encounter
Below is a general guide to sizes you might see. These are representative examples and not a guarantee for any specific vehicle. Always verify with official documentation or by measuring the actual part.
- Metric options commonly seen: M6x1.0, M6x1.25, M8x1.25 (thread diameter and pitch vary by housing).
- Imperial options sometimes encountered: around 1/4-20 or 1/4-28, depending on the component and era.
- Head and drive types can vary as well (e.g., small Phillips or slotted require appropriate driver size).
Because sizes differ by vehicle, these examples should be used as a starting point. Always confirm the exact specification for your model before purchasing or replacing the bleeder screw.
How to determine the exact size on your vehicle
To identify the correct bleeder screw size, use these practical steps. This guidance helps you avoid ordering the wrong part or causing leaks.
- Consult the vehicle’s service manual or the official parts diagram for the exact bleeder screw specification.
- If you have the original part, remove it carefully and measure: outer diameter of the threaded portion and the thread pitch (how many threads per millimeter or inch).
- Use a thread gauge or bring the screw to a parts store to match by thread type and size.
- Check for any torque specifications in the manual; apply the correct torque when reinstalling to prevent leaks.
- Note the screw’s head type (Phillips, flat, hex) and the length, as these can affect fitment and seating.
Correct identification is essential: using the wrong size or pitch can lead to poor sealing and coolant leaks, and in some cases may damage the housing threads.
Summary
There is no universal coolant bleeder screw size. The most reliable approach is to consult your vehicle’s manual or parts diagram, or to precisely measure the original screw’s diameter, pitch, and length. Common possibilities include small metric threads (such as M6 or M8) or rare imperial equivalents, but exact specifications vary by model. When in doubt, verify with a dealer, mechanic, or qualified parts supplier to ensure a proper fit and sealing.
What size is the bleeder screw?
The size of a bleeder screw varies, but common metric sizes are M8x1.25, M10x1.0, and M10x1.5, while common SAE sizes include 3/8-24 and 1/4-28. It's crucial to identify the specific size for your vehicle, as many different sizes are used for different models and years.
Common sizes
- Metric:
- M8x1.25
- M10x1.0
- M10x1.5
- SAE (Standard American Engineering):
- 3/8-24
- 1/4-28
How to find the correct size
- Measure the old screw: Use a measuring tool to find the correct thread size before purchasing a replacement.
- Check vehicle-specific resources: Look up the specifications for your vehicle's year, make, and model, as this will provide the most accurate information.
- Use a universal assortment kit: If you are unsure, a kit with a variety of common sizes can be helpful for finding the correct fit.
- Note the hex size: The hex size (e.g., 10mm, 3/8") for the wrench or socket to fit on the screw can also vary and should be noted. For example, some M10x1.0 bleeder screws have a 10mm hex head.
What size is a radiator bleed screw?
Product specifications
| Manufacturer | Radiator Parts |
|---|---|
| Product Dimensions | 1.5 x 0.6 x 0.6 cm; 3 g |
| Batteries included? | No |
| Batteries Required? | No |
| Item Weight | 3 g |
What size thread is 902 112?
902-112 has M10 - 1.0 inch thread.
What is a coolant bleeder screw?
What is a Coolant Bleeder Screw? The coolant bleeder screw, also known as a coolant air bleeder valve or purge valve, is often a plastic screw or valve that is designed to remove air pockets or trapped air bubbles in the engine's cooling system for optimal coolant pressure and flow.
