how do i bleed brakes on car?

Question

1963 impala

Answer 1

Okay, this'll be a long answer but with brakes you don't get a second chance if they fail. So here goes.

Older cars like this normally have a bleed nipple on the backing plate, which the roundish plate behind the hub and brake assemblies on each wheel.

I am guessing that you don't have a special bleeder kit so I'll tell you the old-fashioned way to do it.

You basically need two people to do this job. One to pump the brake pedal, the other to work at the bleeding itself. To do the job, you'll need a spanner that fits the brake bleeder nipple. It's called a nipple because...well, that's what it looks like. It's designed so that you can slip a length of clear plastic tubing over it to take the fluid as it bleeds out the nipple hole.

Here's how you do it: First, make sure that the brake master cylinder is full. If it isn't then top it up with new, clean fluid. Never 'recycle' old fluid. Now you will need to have good access to those nipples. That means have the car up on a hoist or at least on ramps. Worst case is jacks and solid blocks of wood (NOT stones or bricks. NE-VER!! They can suddenly crumble and if you're under the car fixing something you can get squashed...) You can crawl under the car to do this bit it's awfully awkward. In that case at least turn the front wheels left or right so you have best access to the nipples.

Find one of the brake nipples and check that the spanner fits real snug. A ring spanner is best. If the nipples are very tight you may be able to loosen them off a touch with a socket spanner but you can't use it while you're bleeding so you still need a jaw or ring spanner. Put the spanner on, then slip your length of plastic tube over the nipple and run it down into a clean glass jar, which already has some fluid in it. The end of the tube should be in the fluid.

Now your partner pumps the pedal until it firms up. (If you've got air in the lines obviously it'll need pumping up.) Then you open the nipple by unscrewing it about half a turn anti-clockwise. Fluid will start coming out and so will the air. Tell your partner (who's still got foot on brake pedal) to give you a yell when the pedal hits the floor. Partner holds pedal down and you tighten the nipple. You must tighten it up before partner lifts off the pedal or you can suck air back into the lines, depending on exactly what the setup is. So, okay, the nipple's closed. Partner pumps again, yells when it's firm, you open nipple again, bleed fluid, watch for air bubbles, and so on.

Basically it's like this. Partner pumps and says, "Okay.Pedal's up!"

You yell, "Hold it on!"

Open nipples and bleed.

Partner yells, "Pedal's down."

You yell "Hold it there," and close nipple then say, "Okay, pump it!"

And so on.

There is a school of thought that you can just pump away and you don't need to open and close the nipples. My Dad says that with these older cars slow and steady is best, like I've written.

That's about it. Check your brake master's fluid level as you go so it doesn't run dry and suck air back into the system. Otherwise, just do each of all four wheels in turn, then go around a second time just to make sure you've got all the air out. And do NOT put the pumped out fluid back into the master cylinder reservoir. It's got little air bubbles and old gunk and rusty bits in it and will not be good for your brakes.

If you proceed in this way you will at least have the brakes good enough to drive the car and maybe take it somewhere, where they can redo the bleed with the best modern equipment. But to get you going it works fine. This is how they did it in garages for years, after all.

Just one thing. Brake fluid is nasty stuff. It is highly corrosive so don't splash even a drop on your paintwork. And rub some barrier cream into your hands to protect them. If you feel burning on the skin, take a break and wash your hands with lots of soap and water. Be VERY careful not to get this stuff in your eyes. It will be agonizing and can cause serious damage and has to be washed out immediately.

Good luck and take your time.

Answer 2

One Man Bleeder review by David Zeckhausen on 2002-09-29 at 08:01:31



I don't like the concept of a 1-man bleeder 'cause it doesn't give you as good a bleed. There are several different types of devices which all claim to be "one-man bleeders" and I'll tell you what I think of each:



1. MyteVac suction pump - don't bother! The reservoir is too tiny on this device to allow it to hold enough fluid to bleed the brakes. You'll find your self emptying the reservoir every couple minutes. And it doesn't generate enough vacuum to pull out any bubbles that are clinging to the walls of rough inner castings on the caliper or bubbles that need to travel any distance downhill. This is simply a very frustrating tool to use.







2. Vacula suction device (or any venturi-based device that you hook to your air compressor). These devices are slightly better than the MyteVac, yet they still don't generate enough force to effectivly remove bubbles. Also, air leaks past the rubber boot, making it impossible to know if the stream of bubbles running down the plastic tube came from your brakes or came from the imperfect seal around your bleed screw. I use mine as an expensive vacuum cleaner to remove extra fluid from the reservoir before I bleed the brakes "properly" with a different technique.







3. SpeedBleeders. These devices are 1-way valves which permanently replace your caliper bleed screws. They claim to allow 1-person bleeding, but don't really work well for a number of reasons. I've installed about 10 sets of these and have found a failure rate of nearly 50 percent. The "1-way" valves too often aren't really 1-way and stuff gets sucked back into the caliper between pumps. Another reason I don't like them is that, if you are in the car pumping the brake pedal, there's nobody watching the plastic hose between the SpeedBleeder and the catch bottle. You don't know when the air bubbles stop coming out, you can't tell when the old, rusty brake fluid has been flushed and new, clean stuff is coming out. And worse, if the plastic hose pops off the SpeedBleeder, you will be pumping brake fluid all over the inside of your wheel well and possibly onto the side of your car. (Brake fluid eats paint!) Finally, the SpeedBleeders don't generate enough of a "jolt" on the fluid to knock loose the pesky bubbles clinging inside your calipers. You need a 2nd person cracking open that bleed screw slightly AFTER you push on the brake pedal. And that would totally eliminate the need for SpeedBleeders and you would simply be back to an old fashioned manual bleed.







4. Pressure bleeders - fluid type. These use brake fluid in a large plastic or metal container and pressurize the car's reservoir with brake fluid. The benefit is that you don't need to stop to refill the master cylinder reservoir each time it runs low. And you reduce the liklihood of getting air in the system because you ran low on fluid. The downside is that you waste a large quantity of brake fluid since, once you open a bottle, it should be used right away or discarded. Excellent for replacing fluid. Simply pressurize, then crack open the bleed screw and wait while the fluid is pushed out into your catch bottle. But, unless you also combine it with a traditional "assistant pumps the pedal while you crack the bleed screw open" bleed, then there won't be enough of a "jolt" to knock loose all the bubbles.







5. Pressure bleeder - compressed air type. This is simply a metal cap with a fitting for your air compressor. The better ones have a built-in pressure guage and an adjustable pressure regulator so you can set the pressure to 20 psi. If you go too much higher than 25 psi, you will blow the reservoir off the top of the master cylinder and I can't even begin to imagine the mess that you will have to clean up before your paint is dissolved by the fluid! (You can blow the top off with a fluid type pressure bleeder too.) The compressed air type of bleeder is my preferred choice since it is compact, easy to take with you on a trip, and doesn't waste any brake fluid. I find that I can usually do the front brakes with one fill of the master cylinder reservoir and the rear brakes on a 2nd fill, meanining the inconvienience of dropping the pressure to zero, taking it off, refilling the reservoir, and then repressurizing is really minimal. However, I do NOT consider this to be a 1-man brake bleeder because I always use an assistant to pump the brake pedal while I crack open the bleeder screw. Combining the pressure bleeder technique and the traditional bleeding with an assistant will consistantly give you the best bleed and the firmest brake pedal.

I strongly advise you to avoid the shortcut of any "1-man bleeder" system and do it right. You'll be much happier with the end result.

Hope this is helpful.
Dave Z.

Answer 3

take it to a maintenance &repairs to get it done