Bleeding brake fluid???'s

Sevan

Founding Member
Dec 4, 2001
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What's up guys,

I want to change my brake fluid completely but have not done it before. Has anyone bled their brakes? Is it hard? What do I need to do? Any information that you guys can provide me would be great. I want to make this as easy as possible.

Thanks

:flag:
 
I found this very interesting for bleeding..

Best $25 fix for brake bleeding problems you can get...

Garden Sprayer Pressure Bake Bleeder

1 each pump type garden sprayer, 1 - 1 ½ gallon capacity (size doesn’t matter much, it just has to be cheap and small enough to be easy to work with)
6-10 feet 3/8” clear plastic tubing
1 each ¼” brass pipe tee
1 each ¼” pipe to 3/8: hose adapter
1 each pressure gauge 0-60 PSI or so – all you’ll ever need is 5- 10 PSI, so the gauge range doesn’t have to be high.
1 each large rubber stopper – this is the hard part to find. It may take some searching to find one that is a snug push fit to the inside of the filler port on the master cylinder. You can use silicone rubber to seal a brass fitting to an old master cylinder cap, but they tend to leak too much.
Home Depot or Lowes has some ¼” brass pipe stock that is continuously threaded in the electric lamp repair department, along with the brass nuts that go with it. This is better than a pipe nipple, since the nuts can be used to secure the pipe in the cap or stopper.
OR if you can’t find the threaded pipe stock,
1 each ¼” nipple, 1 ½”- 2” long

The rubber stopper needs a hole drilled in it for the ¼” pipe nipple or threaded pipe stock. After you drill the hole, use some silicone gasket sealer to seal the pipe nipple as you push it into the rubber stopper. If you used the threaded pipe stock, use the nuts to secure the stock into the stopper.

If you can’t find a suitable rubber stopper, an old master cylinder cap can be used. Drill a ½” hole in the center for the pipe fitting. Cut the brass pipe stock to about 1”- 1 ½” long, the exact length isn’t too important. Push it through the hole in the master cylinder cap and thread one nut on top of the pipe stock where it sticks though the cap. Put another nut on the other side of the cap to lock the pipe stock in place. Apply some silicone rubber gasket sealer to both sides and when it is dry, screw the ¼” pipe that sticks out of the top of the cap into the tee.

Remove the sprayer hose and wand from the garden sprayer. You may find it easier just to cut the sprayer hose off short and connect it to the 3/8” plastic tubing. The idea is that the 3/8” tubing connects to the pickup tube inside the sprayer in a reliable, leak proof fashion. Another alternative is to remove the spray nozzle from the end of the spray wand and connect the 3/8” tubing to the wand. This leaves the hand valve in place and may be useful to start/stop the flow of brake fluid.

The 3/8” plastic tubing connects to the pipe tee using a push on hose barb type adapter. The pipe tee has one port for the gauge, one for the 3/8” hose and the other to connect to the rubber stopper or master cylinder cap that you modified.

Fill the pump sprayer with a quart of brake fluid. Set the garden sprayer on the ground and screw the pump handle down tight, and pump until brake fluid fills the plastic tubing. Then put the modified stopper or master cylinder cap on the master cylinder and pump slowly to make sure that nothing leaks or pops loose. No leaks, continue pumping until you get 5-10 PSI. Put a 6”-12” length of clear plastic tubing on the bleeder ports. Then open the bleeder ports on the wheel cylinders one at a time and bleed until the bubbles are gone. I use a 2 liter soda bottle with a coat hanger to catch the fluid . DO NOT REUSE THE OLD BRAKE FLUID. Repeat the process until you have finished all 4 wheels. You will have to pump the sprayer several times to maintain the 5-10 PSI needed to do the job. When finished bleeding, loosen the pump handle to relieve the pressure, remove the stopper/modified master cylinder cap and test the pedal.

http://forums.stangnet.com/showthread.php?t=461384
 
If you have access to a MityVac hand vacuum pump, you can do this by yourself. If not, you'll need a partner to help you. Jack the car up, jack stands under all four corners, remove all 4 wheels/tires. Check to be sure you can easily loosen all the bleed screws. In older cars/calipers, they are sometimes hard to work with.

Remove master cylinder cap, and use a turkey baster to remove as much of the old fluid as you can. Be VERY careful -- brake fluid will ruin any painted surface it's spilled on. You'll need a container to put the used fluid in, and a rags/towels covering things so you don't spill drops on any painted surface you don't want ruined.

DO NOT remove fluid all the way to the bottom of the cylinder. You always want the drain/pickup point of the cylinder to be covered with fluid so you have no chance of introducing air into the system. Once you've removed as much as you safely can, top up the cylinder with the new fluid (be sure it meets your cars specs). Put the cap back on.

What you want to do is draw that new/clean fluid through all the lines and out the bleed screws. I usually start with the passenger side rear brake as it is the farthest away from the master cylinder, and there's the most amount of line between it and the cylinder. Put your wrench on the bleed screw, and put a clear rubber hose over the nipple and down into a clear container. Have your friend apply pressure to the brake pedal. Break the bleed screw open, and fluid should start running out of the valve and through the hose. His foot will be able to press the pedal to the floor as he pumps fluid out the line. Keep the valve open until he calls out "Down!" letting you know his foot is on the floor. IT'S CRITICAL that he keep his foot down until you've closed the bleed valve and holler "Closed!". If he let's up on the pedal while you've got the valve open, it can draw air into the line from the bleed valve. You don't want that. So, he hollers ready and pushes, you open the valve, he hollers down when his pedal is on the floor, he holds it there till you close the valve and holler closed, then he let's the pedal up and applies pressure at the top again. He hollers 'ready' and you open the valve again. You keep repeating the same steps over and over until you start to get the clear/clean fluid through the clear hose that's attached to the bleed screw. Once you've accomplished that, you move to the other rear brake - repeat. Then to the passenger side front, then the driver's side front. Periodically, you must stop, and go check the level of brake fluid in the master cylinder. UNDER NO CIRCUMSTANCES can you let it run dry - that means he's just pumped a bunch of air into the system - and you don't want that. If you've got a third person, they can monitor the master cylinder and add fluid to keep it from running dry as you're pumping it through.

If you have a mity vac, then instead of someone pumping the fluid through with the pedal, you simply suck it out of the bleed screws with the mity vac. It takes longer as you can't go as quickly, and you have to keep stopping to be sure the master cylinder is topped up.

Ideally, you'll have a pressurized container that screws to the top of the master cylinder, and pushes fresh fluid into the system. With that attached, and under light pressure, all you have to do is crack the bleed valve and let the fluid flow until it comes through clean. But we don't all have those pump-up tanks to dispense the fluid with.

Got it? It'd be best if you had someone that's done it before to help you through the first time. The real risks are 1) fluid on painted surfaces, and 2) air in the system. Good luck with it.
 
Actually Rick's are great for building the kind of 'pressurized container' I referred to at the end of my comments. If you're gonna be doing this often, it's WELL WORTH the time to follow his instructions and build the device. It will allow you to quickly replace your fluid by yourself. But, it's not necessary to do it in order to accomplish the bleeding. I've been bleeding them for 30 years as described above. My wife was the happiest person in the world when I got the mityvac as she got tired of pumping the pedal with me hollering "what did you say?" from under the car. :) I printed off Rick's instructions before so I can build me one. I inherited a pump-up sprayer from the people who owned our home before us - gonna put it to good use.

Oh - one more thing. Once you've opened a bottle of brake fluid - use it, and/or throw the rest away. Fluid is extremely hydroscopic (it absorbs water/moisture) and is no good once it has done so. Unsealed bottles will absorb moisture.