High temperature stability. Resists corrosion and oxidation. Maintains high boiling point. Lubricates rubber and metal parts. Easily mixes with other DOT 3 brake fluids.
It would be convenient if this formula was available in other bottle sizes.
Affordable. Available in 3 sizes. Protects metal components from corrosion. Works to shield brakes from common issues that stem from every day usage. Lasts longer than the average brake fluid. Works with disk, drum, and ABS brake systems.
Double-check to ensure that the bottle is securely sealed as soon as it arrives.
Available in 32oz. and 1 gallon sizes. Extra-high boiling point. Affordable. Made for disc, drum, and ABS brake systems.
It’s a simple solution that doesn’t do anything that its competition doesn’t.
Prevents brake system corrosion. Protects against brake failure due to vapor lock. Intended for disc or drum brake systems.
STP is a little on the pricy side, but it is a premium brake formula drivers have trusted for decades.
Handles high boiling point before giving out which is a plus in hilly areas. Lasts a lot longer than other brake fluids. Works on a wide variety of brakes.
Some reviewers thought the packaging could be a bit better.
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Despite the introduction of more modern versions, DOT 3 remains the country’s most popular brake fluid. There’s a common misconception that the newer DOT 4 and DOT 5 are more advanced, but that’s not entirely accurate, and there are good reasons you might be better off sticking with DOT 3.
Hydraulic systems, like the one used for the brakes in your vehicle, need fluid to generate pressure. Water isn’t a good choice because it causes rust and boils too easily. Your brakes can hit over 350°F with ordinary road use, and as much as 1,000°F under heavy loads like racing. Petroleum-based oils are often used in machinery, but brake fluid uses a combination of solvents, lubricants (often synthetic), and corrosion inhibitors. These components also make sure the brake fluid doesn’t freeze.
DOT system: The DOT (US Department of Transportation) system of numbering brake fluid started with DOT 1 and DOT 2, but both are now obsolete. That makes DOT 3 the “baseline” product, but there are also DOT 4, DOT 5, and DOT 5.1. What are the differences?
Mostly it’s about boiling point, and DOT standards quote two: dry boiling point (when new), and wet (degraded) boiling point. The latter is when the brake fluid has absorbed 3.7% water, which takes about two years. In effect, it lowers the boiling point and thus reduces efficiency. The following numbers are minimums in order to comply with the stated category:
DOT 3 remains the great all-rounder, but other formulations can take higher temperatures. Some modern antilock braking (ABS) systems get very hot, so DOT 3 isn’t always recommended. The same goes for racing vehicles. Often, but not always, these use DOT 4. (Note that some manufacturers’ DOT 3 specifications are higher. If you’re regularly making long trips with lots of braking, or you like to take your classic car to track days, these are a good idea.)
DOT 5 is silicone-based, so it doesn’t absorb water and can take higher temperatures as a result. It also doesn’t degrade as quickly. However, it does foam and can create air bubbles, which reduce effectiveness. Most vehicle manufacturers don’t recommend it, so it’s largely used in military vehicles. The fact that it doesn’t absorb water means it won’t corrode braking systems if the vehicle sits unused for long periods.
DOT 5.1 is chemically similar to DOT 4, and it can be mixed with it. It’s not silicon-based, but it performs like DOT 5. However, at many times the price of DOT 3, it isn’t popular, and in most cases, it doesn’t offer sufficient benefits to be worth the extra money.
You want to buy DOT 3 brake fluid because that’s what the manufacturer says to put in your car or truck, but which one? To be fair, there are a lot of similarities, and it isn’t easy to choose between them. The good news is it’s pretty hard to go wrong as long as you follow a few precautions.
Most modern DOT 3 brake fluids use synthetic lubricants rather than traditional mineral oil, but there are exceptions (some Rolls-Royce models, for example). Wherever possible, use what the manufacturer recommends, and don’t be tempted to use DOT 4 because you think it might improve performance. Some vehicles (typically Australian, but also Asian) use a different form of rubber than American manufacturers, and a few brake fluid formulations can attack the compound. Not a good idea! Mostly you’ll be fine, but you don’t want yours to be the exception, so double-check.
Although it’s important to choose the right type of DOT 3 brake fluid, that doesn’t mean you’re restricted to the original equipment manufacturer, such as Toyota, Ford, Honda, or Chrysler. Although the difference might not be huge, these are often a few dollars more expensive, and products from the major lubricant brands are as good or better.
You may also see an SAE rating (typically J1703), which means it conforms to or exceeds the standards set by the International Society of Automotive Engineers as well as the DOT.
Check that the brake fluid is compatible with your braking system: drums, discs, or ABS. Most work fine with the first two but not always with the latter.
Service life is often quoted as two years, but it is three for some brands. That means it’s probably more resilient to the effects of water absorption and doesn’t break down as quickly.
Brake fluid bleeder: ARES Brake Fluid Pressure Bleeder
It’s vital that there are no leaks and that the pressure is constant throughout your braking system. In auto shops, they use a compressor-powered tool, but these aren’t cheap. This affordable manual pump is ideal for the home mechanic. It works on disc or drum brakes and makes it an easy one-person job.
Hand protection: Gloveworks Heavy-Duty Gloves
If DOT 3 brake fluid can eat through auto paint, imagine what it can do to your hands. Nitrile offers better protection than latex against oils and solvents, and these gloves are extra thick for better tear and puncture resistance. They also have a textured surface for a secure grip on your tools.
When we put together a product review, we usually like to give an indication of budget, mid-range, and expensive options. With DOT 3 brake fluids, there isn’t really enough variety for us to do that.
If you buy a cheap DOT 3 brake fluid, you can get a gallon for around $20. You’ll pay $15 to $25 for a quart from a premium brand, but most vehicles only need a quart. In two years’ time, the cheap gallon stuff will have degraded — all brake fluids do — so it’s a false economy.
The bottom line is to make sure it’s the right type of brake fluid for your vehicle and buy the best. The difference isn’t enough to buy you a pizza!
If you buy a pre-owned vehicle, there’s a good chance you won’t know when the brake fluid was last changed. If it’s a car you’ve had for years, maybe you don’t remember whether it was done last year or the year before. Here are a few indicators that a change is due:
A. Unfortunately, there’s no one answer. It depends on the vehicle and the maker. Some manufacturers say every 20,000 miles, others every 40,000 miles. Some say two years, some three, and some just say “periodically”! The only safe course is to go with the period set down in your owner’s manual. If you can’t find the information, go for the shorter period: every two years. Brake fluid isn’t expensive, and it’s better to be safe than sorry.
A. It’s not absolutely necessary — you could just top up your brake fluid reservoir and bleed the brakes to get rid of any air — but it’s the perfect opportunity while you’ve got the car in the air and the wheels off. It will also make sure your whole braking system is in prime condition.
A. One recommendation is to pour it into a tray of kitty litter, let it evaporate, and then throw out the residue. We strongly disagree with that method. Brake fluid contains dangerous chemicals (including heavy metals) that should never go into ordinary trash or where there’s any chance of it getting into drains or waterways. Many auto parts stores will take it (in a separate container from other vehicle fluids), or you can contact your local waste authority for hazardous waste recycling locations.
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