17 votes
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Cleaning brake fluid (general tips)

Standard automotive brake fluid (DOT 3,4 and 5.1) are made from polyethylene glycol (PEG). PEG is soluble in water, methanol, ethanol, acetonitrile, benzene, and dichloromethane, and is insoluble in ...
Fred Wilson's user avatar
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13 votes

Brake flush vs. Replacing the brake fluid

There is no difference between the two. To replace it, you have to flush out the old brake fluid with new fluid. See this answer on how to bleed brake lines for more details.
Zaid's user avatar
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11 votes
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How can I dispose of the waste products I get from working on my car more effectively?

tl;dr: You are doing a better job than most, and as a result reducing your chemical footprint further will largely require being more proactive about safe chemical disposal than most people are ...
Max Goodridge's user avatar
11 votes
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What actually happens when there is no brake fluid in the brake fluid reservoir?

Not having brake fluid in your car won't destroy the brakes, but whatever you hit when the brakes don't work just might. :) The brakes in basically every passenger car since the 50's are ...
cdunn's user avatar
  • 9,316
9 votes

What are all the different types of fluid in a car and a short summary of their use?

Depending on the car model and the technology used, not all fluids I mention here do exist. Here is list of all that I know of: fuel (some cars use two typed of fuel, e.g., petrol and gas, so they ...
masgo's user avatar
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9 votes
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What is the difference between DOT4 and DOT5 brake fluid?

For everyone's edification, here are the dry/wet boiling point specifications for the different brake fluids: Dry boiling point Wet boiling point DOT 3 205 °C (401 °F) 140 °C (...
Pᴀᴜʟsᴛᴇʀ2's user avatar
9 votes
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What to do if you don't know if you have DOT 3 or DOT in your brake lines?

Dot 3 and Dot 4 are mixable, you can use whatever you want. Just do not put Dot 5 into it, thats a whole different thing and not mixable with Dot 3 or Dot 4.
Martin's user avatar
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8 votes

What is the difference between DOT4 and DOT5 brake fluid?

The biggest advantage to DOT5 brake fluid is that it is hydrophobic meaning it doesn't like water. This is in contrast to DOT 3, 4, 5.1 which are hygroscopic which means it will absorb water even just ...
vini_i's user avatar
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8 votes
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Brake fade and spongy brakes at high speeds

Based on what you have posted, changing the brake fluid is not going to solve the problem. It's just going to provide a clean new fluid to boil when your brakes stick. If I read what you said ...
cdunn's user avatar
  • 9,316
8 votes
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Did I toast my caliper?

Any sort of brake fluid leak is a serious issue which needs to be fixed for several reasons. Any fluid leak means that air is also getting into the system which will accumulate and degrade braking ...
Chris Johns's user avatar
  • 1,596
8 votes

Is it sufficient to cycle out brake fluid as opposed to "replacing" or "flushing" it?

There's one slight problem with your theory. The fluid which goes out to the brake cylinders/calipers stays out there. It will never come back to the master cylinder. You have to do something to ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
8 votes
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Brake fluid heat

Short answer: It gets REALLY hot - like, way over 100C (decimal). And, as @SolarMike's answer states, the water that the fluid absorbs from the atmosphere likes to vaporize under those conditions. ...
3Dave's user avatar
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6 votes
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What are all the different types of fluid in a car and a short summary of their use?

There are quite a lot of different fluids inside a modern car. I tried to group them by purpose. Hydraulic Fluids General use: Hydraulic fluids are used to transfer power from one point to another ...
user5626466's user avatar
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6 votes

Clutch sticking, wait until engine's warm

It sounds like your clutch master cylinder is initially letting fluid past the piston seals. Pumping the clutch pedal sounds like it gets the piston sealing again so that the clutch starts to work. I ...
HandyHowie's user avatar
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6 votes

Brakes don't work

If your brake pedal went to the floor it means that there was not enough hydraulic pressure to apply the brake. If they were working fine before and never felt squishy then your master cylinder has ...
rviertel's user avatar
  • 1,169
6 votes

Can I put DOT 4 brake fluid into DOT 3 brake?

You can absolutely use DOT4 in place of DOT3 brake fluid. The only thing you'll need to do is completely purge the system of the old DOT3 fluid to take advantage of the DOT4 features (higher boiling ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
6 votes
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Brake Fluid Bleeding Procedure

The ONLY way I've ever seen/heard/done to manually bleed the brakes is exactly like what the workshop manual is stating. You need to do it in the order presented or you'll be defeating your purpose. ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
6 votes
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How does the brake fluid return to reservoir in Disc Brakes after brake pedal is released?

In the caliper, the seal is designed so when you press the brake pedal and fluid enters, the seal twists sideways. When you release the brake pedal, the force of the seal pushes the piston and thus ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
5 votes
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Motorcycle front brake lever too close to grip

It seems as though the plunger in the master cylinder isn't retracting after use Occasionally when motorcycles are stored you can run into this problem. Older brake fluid along with a bit of ...
DucatiKiller's user avatar
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5 votes
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Changing fluids (power steering and rear differential): when and why

When buying a used car it's usually a good idea to change all fluids, just so you know exactly when they were changed, and can start your own fresh service history. This may be part of the reason why ...
MooseLucifer's user avatar
  • 6,037
5 votes

Is failing to change brake fluid a life safety issue?

YES. A big Y-E-S. It's a huge safety issue. See, braking fluid absorbs(even attracts) water over time, not so much over usage, if at all. Brake fluid gets really hot, even more under sustained braking ...
Bart's user avatar
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5 votes
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Brake caliper leak while pushing piston back

If your caliper has any brake fluid coming out of it, it's time to rebuild/replace the caliper. There should be absolutely no fluid loss anywhere in your braking system. If it is leaking at the ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
4 votes

Mixing DOT 4 with DOT 4 synthetic

DOT 3, 4 AND 5.1 can be mixed. They are compatible. None of them are compatible with DOT 5 that's silicone-based. I just bought some Motul DOT 5.1 and it says on the front label: "NON-SILICONE base ...
Houckster's user avatar
4 votes

Brake pedal soft after changing pads

A number of things could have happened: You let air into the system, either by pushing the piston out too far or by un-doing the bleed nipple. The system has developed a leak. You could have either ...
Newbie Noob's user avatar
  • 2,781
4 votes

When should brake fluid be changed in a Honda 2016 CRV?

Most cars have brake fluid changes every 2 years. It may be occasionally the case that car manufacturers experiment with longer intervals, finding them to be unsuitable and reverting back to the ...
juhist's user avatar
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4 votes

Brake fluid heat

If there is a small amount of water in the brake fluid in the caliper and the brakes are used severely for an extended period the heating can cause the water to change to vapour. The issue is that ...
Solar Mike's user avatar
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4 votes
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99 Honda Odyssey had brake fluid flushed 4700 miles (27 months) ago. Does it need to be replaced again?

Brake fluid replacement is not determined by the amount miles on the vehicle, but by the amount of time. That's because it is hygroscopic, which means it absorbs water. It does this through the rubber ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
3 votes

Does brake fluid require topping-up as brake pads wear out?

Er, not so much. I'm assuming we're talking Motorcycle here, right? What if there is a slight leak in the brake lines somewhere? You'd be losing fluid and that would NOT be a good indicator of ...
zipzit's user avatar
  • 6,559
3 votes
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Specifics about changing a brake caliper on 2000 Toyota Camry

What hardware if any should be replaced every time the brake line comes off the caliper? I know there's a brass washer for the banjo bolt, but what is the criteria for replacing it? New/re-furbished ...
race fever's user avatar
  • 3,363
3 votes

Clutch sticking, wait until engine's warm

I agree with @HandyHowie in that it sounds like your clutch master cylinder is on the way out. Something to check before you go this route, though, is the hydraulic fluid level for the clutch. Looking ...
Pᴀᴜʟsᴛᴇʀ2's user avatar

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