The BEST way to bleed brakes

A little background before I begin because I'm sure that this will cause a stir and that's not my intent. I used to teach braking systems and ABS diagnosis for 4 years. There is a lot of different consensus on how to bleed brakes-pump and hold, vacuum, reverse bleeding, power bleeding. None of them I have read are incorrect however, there is possibility of causing other problems with the system by doing it some of these different ways. Most people don't have a power bleeder at home and with the newer ABS systems, these are not the best method anyway. Besides, usually power bleeders are filled with brake fluid that can be months old and most likely already contaminated and "wet". Vacuum bleeding is an excellent way, but again, most people don't own or have access to a good vacuum machine. A Mityvac is NOT a good vacuum machine although if you are competent with it, you can do vacuum bleeding, but it's not necessary to even use it in this method.

 

NOTE: Working on brakes should not be attempted unless you feel that you are competent in understanding the following instructions.

 

We've all been taught the "Pump it up, Hold it, Tell me when it's on the floor, OK, Pump it up again, Hold it again, tell me when it's on the floor", etc. method, and while this does, in fact, work for bleeding the system, it can cause problems that are not immediately apparent. This method pushes your master cylinder into zones that it's not used to being and can cause issues with the seals and cups inside because of corrosion and wear. Sooner or later down the road, and it doesn't always happen, but your master cylinder can fail from grit and corrosion that was loosened when you did your bleed. At that point, you are purchasing an expensive piece, having to do the labor, and then having to do the whole damn thing all over again.

 

So with that being said, here is the best way to bleed your brakes:

 

When bleeding your brakes, remember this: Gravity is your friend, unlike around our waistlines (I can attest to THAT fact unfortunately). It's very simple to bleed your brakes, remove the air, and never invade your master cylinder where it shouldn't be invaded.

 

I have taught this method for over 30 years and have never had a single issue with a system that is in good working order. If there are problems with your vehicle in the ABS controller, proportioning valve, lines, or calipers, then the vehicle needs to be repaired before attempting this method. This will NOT make up for worn parts such as pads, rotors, calipers, master cylinder, booster, etc.

 

Gravity bleeding is easily done by a single person, but the only downside is that it takes a bit longer to do and you MUST pay attention to your master cylinder and fluid level. Here's how:

 

Clean the outside of your master cylinder thoroughly around the cap area to make sure no dirt can enter when you remove the cap. Open your master cylinder and remove as much old fluid as you can from the reservoir. Remove the floating screen (if it's a Subaru) so you can reach all the way inside. I use a turkey baster that I have mounted/glued a piece of curved brake line in the tip so I can reach around through the side slots and get as much fluid out of the bottom reservoir as possible. Make sure you have wet rags around in case you spill some fluid when you are sucking it out. Wipe any spilled fluid up immediately with a wet rag and rinse the rag. Once you have it as empty as possible, fill it with the new fluid of your choice and reinstall the cap. ONLY use a NEW bottle-never one that's been sitting around half full, even if it's only a few months old, and put the cap back on between fills of the master cylinder. Make sure you have enough NEW fluid to completely flush your system-a 32 oz. bottle/can is a good size.

 

NOTE: NEVER USE DOT 5 SILICONE FLUID-IT IS NOT TO BE USED FOR ABS SYSTEMS. (If you have questions about this, PM me and I'll explain exactly why it doesn't work.)

 

Jack up the car at all 4 corners and place it on stands (if you have a hoist, even easier). Remove the wheels and break loose each of the bleeder screws and then check them to make sure that they are open and not rusted shut. If they are, use a piece of wire or drill bit to open the center and side holes and then reinsert back into your calipers or wheel cylinders.

 

NOTE: If you have bleeders that you think are going to break off, there are several methods you can use to loosen them. If you have access to an oxy/acetylene (cutting/welding, not a propane) torch, you can heat the caliper JUST right around the screw, red, not flowing metal red, but just red, and quench them with water. (DO NOT DO THIS WITH ALUMINUM CALIPERS). This will make them come loose easily. If you don't have a torch, soak them in PB for a day before you try to remove them. Find a socket that fits the bleeder but doesn't bottom all the way to the caliper. Put the socket on the screw over the nipple and tap the flat end of the socket lightly several times with a hammer (NOT A BFH-a small hammer) and then try to loosen it. It may take several times of trying and tapping, but be patient. This helps the PB penetrate and also loosens the threads with the shock. (You CAN do THIS with aluminum calipers). Once you have them loose, see above about making sure they are open.

 

Find some clear hose that will fit snugly on the nipple of the bleeder screw long enough to reach from the bleeder down into a container on the floor. Go-kart/atv/dirt bike fuel hose works perfectly. Put the hose over the bleeder screw nipple and place the open end into the container (clear container with graduations it is IDEAL so you can see how much fluid is coming through-a Ratio-Rite cup is perfect) and open the bleeder screw taking care to make sure that the hose stays pointed in the cup. It will take a minute but you will see fluid building up above the bleeder in the hose (only on the rear as the bleeder screws point straight up-the fronts flow quickly without a buildup in the hose) and then it will start to drip into the container. Remove the master cylinder cap and "LET 'ER DRIP" for a while-usually 10 minutes is a good number to use as a beginning but it may take as long as 15. You MUST maintain a constant vigil at your master cylinder to keep it full as it will slowly go down. DO NOT LET IT GET DOWN TO EVEN HALF FULL-JUST PAY ATTENTION AND KEEP THE DAMN THING FULL...LOL. Keep adding the fluid and once you see about 6 oz. in the clear container, then close the bleeder and move to the left rear. Refill the master cylinder and do exactly the same thing and look for about 6 oz. Move to the right front-6 oz., and the left front-6 oz.

 

Use just clean water to clean up any mess that you may have made and use a wet rag to wipe down the calipers to make sure that there is no fluid that leaked onto the paint (if they are painted). Put your floating screen back inside of the master cylinder, refill a final time, and install your master cylinder cap.

 

NOTE: Make SURE to install the master cylinder cap before completing the next step.

 

Leave the car on the stands and start it and gently push your brake pedal several times. You'll find that the pedal is engaged sooner and firmer.

 

In approximately an hour, this method will completely flush your entire system and replace all of the fluid with new. Reinstall the wheels, lower the car, check the lug nuts for torque, and then test drive the car. Check the master cylinder a final time after your test drive.

 

Enjoy ! ! !

 

I posted this in the 4th Gen by mistake. Better to have it in two places than no places, I suppose...LOL. Sorry about that.

Any pics of this process? I know it sounds simple enough buy some people are more visual learners (me)

. Anyways, if not, great right up!!

Not really much to show in photos. Please PM me and I can help walk you through it. It's just a matter of getting the car up, wheels off, and then working the bleeder screws after you drain and refill the master cylinder. You can even just let it drip into a bucket without the hose if you want but if you have painted calipers or brackets, you'll want to use at least some kind of hose. I do drum brakes that way-just let it run down the backing plate and drip...LOL.

We've all been taught the "Pump it up, Hold it, Tell me when it's on the floor, OK, Pump it up again, Hold it again, tell me when it's on the floor"

Whoever tells people that is completely wrong for the reason you mentioned already: you can destroy your MC. I know this because I destroyed the MC on my old car and had to replace it... which was an even bigger pain because then I had to bench bleed the MC using some custom bent brake lines.

 

Anyway, I was taught that if you use the pump method, you have to crack the bleeder screw SLOWLY and BARELY while the assistant is holding the pedal down and let out a squirt of brake fluid. The trick is to let a squirt out and immediately shut it again. And then tell your assistant to release. The pedal should never be floored.

 

That method worked okay for me but I stopped because 1) if your wrench slips, your pedal gets floored and 2) it requires an assistant. I've since then gone to using a Motive pressure bleeder.

The "pump it" method has been taught for many years, even in service manuals. I never was a fan of it, even when I learned it back in 1974, and that was before ABS systems where even the smallest speck of dirt could foul an ABS controller. The method you were taught (to never let the pedal hit the floor) is actually the correct one but unfortunately, it's difficult to modulate for many people and even if you do control it closely, the results are exactly what you went through. The master cylinder still pushes through territory it hasn't been through before, and can dislodge corrosion and/or rust, which can ruin the seals and cups.

 

As I stated, none of the methods are "wrong", depending on who you ask, but I'm not a fan of pressure bleeders and I even own one, including a vacuum bleeder that hooks to an air compressor and generates vacuum to pull fluid through. The problem with pressure bleeders and vacuum bleeders is that they can dislodge any speck that happens to be stuck to the inside of a brake line and force it into the ABS controller or proportioning valve, which can cause a light, which EVERYONE hates. It only takes a spec of .005 micron to foul many of the ABS controllers out today.

 

I know people that use pressure bleeders, swear by them, and would never change. My personal feeling is that they were developed to make it faster and also make it a one man operation which is a good thing. They were also first developed way before the complexities of today's systems. By using only the weight of the fluid and gravity, there is almost no chance of knocking anything loose or pulling it out of the bottom of the reservoir and forcing it down into the lines.

 

Brake fluid does not recirculate within the system so the fluid itself doesn't move much other than the floor pedal is pushed to cause the pressure which activates the pistons in the calipers producing force which induces the friction between the pads and rotors and slows the vehicle. (I know, long sentence, but it was done on purpose...LOL).

 

At least with your Motive bleeder, you use it, clean it, and then put fresh brake fluid in it every time you use it. Most pressure bleeders in service facilities, including dealerships, have NEVER been cleaned and someone pours a gallon of fluid in them and then it may take 6 months to use enough of it to need refilling, which is exactly what happens and the old fluid isn't removed.

Not really much to show in photos. Please PM me and I can help walk you through it. It's just a matter of getting the car up, wheels off, and then working the bleeder screws after you drain and refill the master cylinder. You can even just let it drip into a bucket without the hose if you want but if you have painted calipers or brackets, you'll want to use at least some kind of hose. I do drum brakes that way-just let it run down the backing plate and drip...LOL.

 

Alright no biggie, your write up is pretty descriptive as is. I just mainly wanted to see how you connected the tubing to the nipple and the bleeder screw. Thanks for this info though, I might PM you to pick your brain a little

Ill be trying this Sunday, thanks for the write up!!!

I've done a similar trick on Honda's back in the day (put it on 4 jackstands and just let it drip out). I usually had to follow up with a 2 person pump bleed to get any remaining air out. My reasoning was there are higher points in the brake system than the bleeder valve so the air will stay there unless something physically pushes it to the bleeder.

 

The guy who usually helps me puts his other foot under the pedal so he never fully floors the pedal completely during bleeding. You could probably throw a piece of wood or something different back there to accomplish the same thing. I've heard that's it possible to introduce air by flooring the brake pedal during bleeding but the idea of dislodging debris makes sense.

I posted this method on a couple of other forums and several people asked about the reasons to not use DOT5 Silicone brake fluid with ABS systems. I answered one of them and thought I would copy and paste it in here for everyone that may have the same questions.

 

Silicone brake fluid is much thicker which means much slower to move through the system when you push the pedal down, and has a compressibility factor which will make an ABS controller think that you are trying to pump the pedal. This causes the controller to pulse erratically and COULD cause a crash. Silicone brake fluid also gives a spongier feeling pedal (again, due to the compressibility) and as it heats up, important chemicals can evaporate off, leaving the pedal even more spongy and again, COULD cause a crash.

 

Poly glycol based fluids (DOT3, DOT4, DOT5.1) are a thinner fluid that provides a solid compression without any springiness because of the composition of the fluid. The ABS system relies on wheel speeds and pedal pressure and adjusts the pulsation to the wheels that need it. These fluids allow that to happen in milliseconds as the pressure is consistent and solid.

 

Traction control also relies on the ABS system and allows the ABS system to systematically apply brakes to the spinning wheel to equalize the speeds so that both wheels pull the same. Silicone fluid will cause this to be erratic which can actually cause damage to a differential because of the wheel speeds changing all over the place.

 

 

http://www.gomog.com/allmorgan/brakefluid.html A good article about the differences of brake fluids

 

 

http://collision.alldata.com/online2...ot_3_or_41.htm Read the final line in this post.

 

I hope this helps. Please feel free to PM me.

 

Thanks,

 

John

I've used one of these many times... Worth its weight in gold, in my opinion. [ame=http://www.amazon.com/Mityvac-MV8000-Automotive-Test-Bleeding/dp/B00265M9SS/ref=sr_1_1?ie=UTF8&qid=1365997575&sr=8-1&keywords=brake+bleeder]Mityvac MV8000 Automotive Test and Bleeding Kit : Amazon.com : Automotive[/ame]

How would you do this with brembo's? I only have them on the front but I guess You'd do the inside first then the outside blender?

How would you do this with brembo's? I only have them on the front but I guess You'd do the inside first then the outside blender?

 

I've done Wilwood calipers and I opened the outside bleeder screw first for about 5 minutes as it's the furthest away and allows fluid to come all the way into, through, and out of the caliper.

I've done Wilwood calipers and I opened the outside bleeder screw first for about 5 minutes as it's the furthest away and allows fluid to come all the way into, through, and out of the caliper.

 

Interesting, I did them by the hold pump and hold method before starting with the inside bill give it a shot once I bleed them again.

I'm doing it right now, so far so good. But yes it takes awhile for the 6 ounces!!

 

Thanks for posting this.

 

On the rear right now, over to the rear left next.

"Remove the wheels and break loose each of the bleeder screws and then check them to make sure that they are open and not rusted shut. If they are, use a piece of wire or drill bit to open the center and side holes and then reinsert back into your calipers or wheel cylinders."

 

Stupid question here, I assume you are cracking each bleeder screw to ensure they will in fact open, then closing them and doing one corner at a time with the drain process?

 

Thanks.

"Remove the wheels and break loose each of the bleeder screws and then check them to make sure that they are open and not rusted shut. If they are, use a piece of wire or drill bit to open the center and side holes and then reinsert back into your calipers or wheel cylinders."

 

Stupid question here, I assume you are cracking each bleeder screw to ensure they will in fact open, then closing them and doing one corner at a time with the drain process?

 

Thanks.

 

Not stupid at all. Answer to your question. Yes. Open each one to make sure that the fluid comes out of them. If you have the rubber cap on them, chances are very good that you'll be fine but if not, then they can clog with rust and crap so that's when you would have to open them up.

 

Once you know they will all pass fluid, then go from corner to corner although I've opened all 4 of them before if I had new long hard lines to fill because it's a little faster.

So you start with all 4 open, drip for 10-15 min then while all four are open you start with the rear driver side? OR you start at the right rear then LR>RF>LF?

No, you only have one open at a time. You only open them so you can verify that fluid will drain from each one.

What is your issue with mityvac units?

 

But another way to break bleeders loose is to actually tighten them slightly and they will break free.

No, you only have one open at a time. You only open them so you can verify that fluid will drain from each one.

 

Got it so up in the stands, start at RR>LR>RF>LF

I just came across this. Great write up. You say go kart fuel line works perfectly, but I was wondering if you knew what size that is? I found some clear line on a siphon pump from autozone. I was hoping that would work but I haven't tried it yet.

I just came across this. Great write up. You say go kart fuel line works perfectly, but I was wondering if you knew what size that is? I found some clear line on a siphon pump from autozone. I was hoping that would work but I haven't tried it yet.

 

Thanks much for the kind words. 1/4" is the size you want. You can also get 1/4" vinyl tubing at Lowe's, Menards, etc. and that works well too and is generally cheaper.

What is your issue with mityvac units?

 

With mine, I would get a lot of bubbles in the vac hose that i assumed was air being pulled thru the bleeder threads into the caliper and out of the bleeder. I was never sure if it was that or just a bad vac hose seal on the bleeder but I never fully trusted it. I trust my Motiv power bleeder completely.

Edited September 15, 2013 by DosRenshos

Another silly question or three. Do you leave the cap on the master cylinder why the wheel is bleeding?

Also, is it normal for brake fluid to Leak out of the threads of the bleeder screw when it's open?

Lastly, should I close the bleed screw before adding more fluid?

Edited September 27, 2014 by thesavo

Another silly question or three. Do you leave the cap on the master cylinder why the wheel is bleeding?

Also, is it normal for brake fluid to Leak out of the threads of the bleeder screw when it's open?

Lastly, should I close the bleed screw before adding more fluid?

 

1. I have it off as I am usually adding to it to make sure it doesnt run dry

2. It sounds like you have the threads too loose

3. Doesnt matter. Just make sure it never runs dry.