Bleeding Brakes

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AKhan87

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I have always done the two people method, using farthest from the brake booster then opposite, then the farthest remaining and then again opposite ends. I always follow the brake pedal to the floor while bleeding the brakes, I figured if I didn't I would loose tension and air can be introduced (not 100% sure my thought process is correct).

Originally Posted By: Lubener
If you are sure you got all the air out, you may have an issue with the master cylinder. While bleeding, you should not press the pedal all the way to the floor. Over time, a ridge wears in the bore of the master cylinder, by pressing the pedal to the floor, the piston goes over that ridged area and the piston get damaged and will start bypassing.
is this correct? if so, what kind of wear am I causing to my brake boosters? I have all my cars on the 3 year maintenance schedule as far as brake fluid is concerned.
 
When doing the 2 person method, I've always just pumped to the floor with no issues. I usually am lazy and just do the gravity feed method, just open up a bleeder and it will eventually drip out, if you keep the master cylinder full it won't go dry and no air can get into the system. My mechanic buddy usually does this too unless the system is totally dry.
 
I've always put a chunk of wood under the brake pedal to avoid traveling to far for that reason. I use a single person method with a vacuum pump now.

Supposedly, during typical use, when you only use a fraction of the master cylinder's full travel. The back end of the cylinder can have rough spots from corrosion or debris, so when you press the pedal all the way down, the seals in the master cylinder can be damaged.
 
I do the pump, hold, helper cracks bleeder, I yell for them to stop, hope they stop before the pedal hits floor, release, repeat.
 
I used the 2 person method for decades with out issues. It is how I was taught. The last 5yrs or so, I have adopted single person methods. I use a gravity bleed, because it tests the integrity of the plumbing. I use an airlock on the bleeder and hand pump the pedal. Both seem to give me a harder pedal than the 2 person method. No need for pressure or vacuum power.
 
Originally Posted By: Lubener
If you are sure you got all the air out, you may have an issue with the master cylinder. While bleeding, you should not press the pedal all the way to the floor. Over time, a ridge wears in the bore of the master cylinder, by pressing the pedal to the floor, the piston goes over that ridged area and the piston get damaged and will start bypassing.


This quote is leaving out important info. This is true IF you have a neglected brake system. There is a section of the bore that never gets used except when the pedal goes to the floor. If the fluid has not been change, corrosion builds up in this section and when you push the piston into this area, the rubber seal will get damaged and cause a loss in pressure.
 
Originally Posted By: andyd
I used the 2 person method for decades with out issues. It is how I was taught. The last 5yrs or so, I have adopted single person methods. I use a gravity bleed, because it tests the integrity of the plumbing. I use an airlock on the bleeder and hand pump the pedal. Both seem to give me a harder pedal than the 2 person method. No need for pressure or vacuum power.


How do you create the airlock? Loop the tubing above the caliper and keep the end submerged in a container of fluid?
 
Originally Posted By: 6starprez
Originally Posted By: Lubener
If you are sure you got all the air out, you may have an issue with the master cylinder. While bleeding, you should not press the pedal all the way to the floor. Over time, a ridge wears in the bore of the master cylinder, by pressing the pedal to the floor, the piston goes over that ridged area and the piston get damaged and will start bypassing.


This quote is leaving out important info. This is true IF you have a neglected brake system. There is a section of the bore that never gets used except when the pedal goes to the floor. If the fluid has not been change, corrosion builds up in this section and when you push the piston into this area, the rubber seal will get damaged and cause a loss in pressure.


Disagree. After thousands of times the brake pedal is pressed, there has to be some wear present in the master cylinder even in a maintained system.
 
So if on thousands and one time I pressed the pedal harder during a panic stop, the piston will go past the ridge and my brakes will no longer work?

If true, I would much rather have brakes fail during bleeding than on the road!!
 
So after reading this, I've gathered that the peddle should be pumped roughly 3/4 to the floor only? Am I reading this correctly?
 
Last edited:
I just paid a shop to do a complete brake flush.

$39.99 and I didn't have to lift a finger.

I do all car related work myself, except brake bleeding. I despise it.
 
Last edited:
Originally Posted By: Throt
I just paid a shop to do a complete brake flush.

$39.99 and I didn't have to lift a finger.

I do all car related work myself, except brake bleeding. I despise it.

If you have correct tool you can bleed the brake very easy and very fast, the biggest problem and time consuming with bleeding the brake is raise the car, put jack stands under it, then remove the wheels, reinstall the wheels and lower the car after done.

The cost of 1 quart brake fluid is less than $10, so you can save up to $30 each time. If you pay $80-100 for correct tool you can get back that money in no more than 4 brake services.
 
Originally Posted By: HTSS_TR
Originally Posted By: Throt
I just paid a shop to do a complete brake flush.

$39.99 and I didn't have to lift a finger.

I do all car related work myself, except brake bleeding. I despise it.

If you have correct tool you can bleed the brake very easy and very fast, the biggest problem and time consuming with bleeding the brake is raise the car, put jack stands under it, then remove the wheels, reinstall the wheels and lower the car after done.

The cost of 1 quart brake fluid is less than $10, so you can save up to $30 each time. If you pay $80-100 for correct tool you can get back that money in no more than 4 brake services.


Agreed. If I had the money for a MityVac I'd order one right now. I hate paying a shop to do it but without the proper tools to do it, I'm okay with the $40 cost.
 
Originally Posted By: Vikas
I hope you watched them do it; otherwise they replaced the fluid in the reservoir and called it a day.


Nah. I checked all the bleeders, they've been wrenched on.

Plus, I can tell there is new fluid in the lines from the increased pedal feel and easiness of braking. Just changing the fluid in the reservoir wouldn't do that.
 
I once was installing new brake lines, but had to leave house for an hour right before I was about to start bleeding. I happened to leave the bleeder screw untightened on one of the brake calipers with clear tube attached lowered into a container.

When I returned I found the container nearly full and master cylinder low on brake fluid. Gravity had bled the caliper! I repeated the same for other lines/calipers. The downside is that you have to wait.
 
Buy 2 feet of clear plastic tubing that fits snugly on the bleeder. Then I fill a 6 oz hot sauce bottle 1/2 way with BF. Submerge the end of the tubing in it. Open the bleeder,then pump the pedal 3 or 4 times by hand.. Close the bleeder and move the set up to the next brake.
 
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