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PowerBleeder - Bleed your brakes the easy way **Revised**

757 Views 0 Replies 1 Participant Last post by  ajkalian
The idea for the PowerBleeder came from me having to bleed my brakes when I did a rear brake job. I wanted to replace the flexible hoses as well since they've been on the car since it was new, and I figured that since the brake lines were original to the car they were due for a change. After a couple of prototypes and some false starts, I came up with what I call a PowerBleeder. Here's how I came up with this helpful addition to my toolbox.

I had used a hand vacuum pump for bleeding brakes before, but it had some problems. If you wanted to do a complete flush, you had to empty the small containter many times. The small container tended to tip over as well. So I fabricated a home made contraption out of a canning jar, and some ABS sheets I had laying around.

In it's simplest form you can just take any Mason jar and drill a couple of holes in it an epoxy two plastic hoses. It will get the job done. It won't cost much, but it looks so cheesy. I wiggled the plastic lines and I heard a small "crack" and the epoxy didn't want to seal to the plastic tubing, and it separated. The hoses still held vacuum, and I could have glopped some more epoxy and then been careful not to jossle the tubes when I bled the lines.

So I decided to kick it up a notch and fabricate one out of ABS plastic. Much nicer looking, much less cheesy. Here's some pics of what I came up with. It worked very nicely, and with a long hose attached to the jar, I could pump the rear brakes from the front of the car, and watch the master cylinder level without having to pump, look, pump, look, well you know what I mean if you have ever done it.

As luck would have it, the pint Mason jar top, fit a Best Foods Mayonaise Quart jar, so that gave me even more capacity that I had planned on. The original ABS setup worked fine the first time around, but had some small leaks. It turns out there was no way to seal the ABS to the glass jar to create a vacuum. I tried gasket material, cork but nothing sealed it completely. It was good enough to bleed the rear brakes, but there were still bubbles in the line from the small leaks. The bubbles didn't hurt the bleeding process, since they came after the brake lines. Much to my disapointment the brake fluid attacked the ABS and the whole thing fell apart in a week. I wasn't sure if the ABS would hold up, and as it turns out it didn't. But the design was OK, the original ABS materials, not so much.

So I had to fabricate the next version out of something tougher than ABS plastic. The answer was kinda staring me right in the face. You can see that I used a jar lid to trace out the ABS originally. Well the jar lid was made of metal, and it had a rubber lip to seal the jar also. All I had to do was to fabricate something to attach to the metal top. Aluminum was my first choice. It's easy to work with, and the brake fluid wouldn't affect it. So I used the original ABS version as a template and fabricated one out of aluminum.

Now I could have just disconnected the flexible line from the hard line in the front, and do it like I did the rears, but I had a better idea. The problem with bleeding from the bleeder screw with a vacuum pump is that you suck in a lot of air along with the brake fluid. It stands to reason because you have to crack the bleeder screw just a bit, to get the fluid to come out, and the air is sucked in past the threads, and where the hose connects to the bleeder screw. It doesn't do any harm, just slows down the process, expecially if you use a hand pump. So I came up with the idea of screwing something into the bleeder screw hole, and sealing it to the brake cylinder so you could pump out the brake fluid without sucking in any air.

My idea was to cut off the end of the bleeder screw, and then adding a rubber or nylon washer to seal it to the master cylinder. So off to Lowes to get some parts. I got some rubber washers, and some steel ones as well. Then this could be screwed into the bleeder screw hole, and then attach the vacuum pump and you would esentially have a sealed system. In theory, that is. In practice it turned out to be quite a different story.

I decided to test it out on the front brakes since I already did the rear brakes. Well, to be honest the new bleeding system worked fine, but I made a real big mess.

Here's what happened. When I did the rear brakes, I noticed Toyota was smart enough to put an upside down "U" where the hard line meets the flexible line. So the brake fluid has to be pushed up and over the "U" to the brake cylinder. So all I had to do was to remove the flexible line and slip the plastic hose over the hard line, and I didn't spill any brake fluid at all.

The regular way you do bleeding is to put the hose over the bleeder screw, open it maybe 1/8 turn and start the vacuum pump, or have somebody in the car pumping the brakes while you loosen and tighten the bleeder screw. Well since my new whiz bang system requires that you remove the bleeder screw entirely, and replace it with the modified one, fluid starts to come out immediately. I knew that it would, so I put newspapers on the garage floor, and used lots of rags. But this new system required a bit more fiddling, to get everything hooked up. Remove the bleeder screw, drip, drip, drip. Start the new shortened bleeder screw, drip, drip, drip. Brake fluid on nitrile gloves, slip, slip, slip. Well fiddling time equates to dripping time. By the time I had everything in place the brake fluid was running down the tire, the hose, the newspaper, and all over me. Mr. Gravity took over the instant I cracked the bleeder screw and didn't stop for a second, and there was brake fluid everywhere. :confused:

Once I got everything hooked up, it went fine. And I was really surprised on how well the new system sealed up, and I got good vacuum, and was very surprised on how much vacuum the little hand pump could pull. In five minutes I was able to fill the quart jar 3/4" full with just the hand pump in about 6 minutes.

But I had to be honest, this needed some work. First off I had to come up with some way to remove and then replace the bleeder screw and not make so much of a mess. Did I mention that the plastic hose came off the bleeder screw when I was pumping ?? That really added to the brake fluid mess. :facepalm:

So I came up with this short length of tubing, call it a pigtail. To keep the original bleeder screw from dripping brake fluid immediately, just put this cap over the screw before you unloosen it. Duh. I also used the smaller diameter tubing for the short length. It fit's very tightly over the shortened bleeder screw, and fits easily inside the larger tubing. It makes a very good seal. I found that this was easier than trying to remove the tubing from the brass barb fitting. Once they get on, they are a bear to get off, especially with brake fluid everywhere. I took a piece of wire and twisted it around the hose where it joins the bleeder screw to secure it from coming loose and to seal it. To keep the brake fluid from draining out after you screw in the pigtail, I added a rubber cap to the end of the tubing.

So now all you have to do is to bunch up a rag under the bleeder screw on the caliper. Remove the rubber cap on the bleeder screw, then using an 8mm socket, or the closed end of a combination wrench, (not the open end) or a flare wrench. Just crack it a bit to break it free. Then replace the rubber cap to keep the brake fluid from running out all over the place, and then remove the bleeder screw.

Put your finger over the hole, (duh) take the pigtail with the shortened bleeder screw on it, and screw in the pigtail. If you're quick, you won't spill too much brake fluid. There's no need to use a flare wrench on the pigtail fitting, an open end wrench is fine, since you don't have to tighten the shortened bleeder screw very tight. Just enough to seal it. If you wrench on it too hard, you will distort the rubber washer, and introduce leaks. Here's what it looks like when the pigtail is just a bit loose. You will see air bubbles in the line, pic on the left. Just tighten it up a little bit, and the bubbles will go away, and you have an air tight seal. Pic on the right.

As an added measure, I clipped some hemostats to the tubing before I removed the cap and installed the main hose. Once you are sure everything is hooked up properly, then you can start pumping. When I did the front passenger side, I spilled just a little fluid, but when I did the driver side, I had perfected the Switch-er-Roo a bit and didn't spill hardly any brake fluid.

Be aware that if everything is sealed properly you will be able to suck a lot of brake fluid in a very short amount of time. Monitor the master cylinder carefully. It won't take too long to empty it. Ask me how I know that. I took a video of the process, and I'll have to admit it is the most boring video you will probably ever watch. The video is about 3 minutes long, and it was taken about 3 minutes into the bleeding process. Notice the level of the brake fluid in the jar behind the round pressure gauge. At the beginning of the video it is just touching the bottom of the gauge and at the end it is higher. Also notice how slowly the vacuum bleeds off on the gauge. When the dial is at the 12 o'clock position it represents 15 in. I only had to pump it once during this three minute period. Notice also that every once in a while there will be a bubble in the line, and you can see it move slowly. If you've ever done this with a hand held vacuum pump you might remember that there is a constant stream of bubbles in the line. This sealed up so well that there are virtually no air bubbles introduced anywhere in the system. At the end of the video you can see that about one inch of fluid was added to the jar.

Once you are satisfied with the amount of brake fluid flushed, depress the valve on the vacuum pump to release the pressure. Then remove the bleeder line from the pigtail, and cap the pigtail with a rubber cap. Unscrew the pigtail and re-install the stock bleeder screw and hand tighten it. The brakes at this point should be fully bled, but just to be on the safe side, attach the bleeder line to the bleeder screw. Then pump up the vacuum pump to say, 15 inches, and then just crack the bleeder screw open 1/8 turn or less. You should see some fluid and a steady stream of bubbles come out of the bleeder screw. Don't freak out, the air is coming from around the threads in the bleeder screw. After 10 seconds tighten up the bleeder screw, remove the bleeder line and tighten up the bleeder screw with a flare wrench or a closed end wrench. Top off the master cylinder and you are done.

You need to keep a close eye on the brake level in the master cylinder. I removed the filter for this bleeding process and used a wide mouth funnel that fit nicely in the master cylinder opening. If you don't pay attention, you will hear a gurgling sucking sound, and that means that you let the level go to low, and will have to get all the air out of the lines from the master cylinder. NBD, because you can suck out a pint of fluid in no time. Just watch the level carefully. When you are done, don't forget to replace the filter and cap.

This whole contraption worked very nicely but having to constantly refill the master cylinder became a hassle. Especially if you didn't watch it carefully and it got low and started sucking air. I wanted to fashion some sort of way to fill the master cylinder from a larger container and not spill brake fluid all over the place.

I got the idea of using something like a blood transfusion bag. That is something to hang upside down, maybe attach to the hood latch, and then it would slowly feed brake fluid into the master cylinder as the hand held vacuum pump sucked the brake fluid from the bleeder screw on the brake caliper. Here's what I came up with. Most everything was made from parts I had laying around the shop. There was some fabrication involved, but nothing all that complicated.

I made the main container out of an empty quart container that the brake fluid came in. I just cut the bottom off and mounted a hanger that I bent out of some scrap metal I had left over from another project. I needed something to hang it with, so a spare eye bolt did the trick. I really wanted a clear bottle, so I could see the brake fluid level as it drained, but didn't have one around. But I did have a suitable container, that turned out to be the one the Brake Fluid came in. The configuration of the hanger is such that it can be moved to virtually any container that I finally decide to use.

I wanted to be able to move the cap mechanism like the hanger to any bottle that I might want to use, so I made up a barb with a 1/8" threaded nipple to fit through the 3/8" hole that was drilled in the cap. In order to seal the cap I used rubber washers on either side of the nipple. Pipe threads are tapered and they don't make nuts for them. So I made my own. Using a regular 3/8" nut and a 1/8" pipe tap, I drilled the threads out of the nut, and re-threaded the nut with pipe threads. You have to run the pipe tap all the way through the nut so the threads aren't tapered. Then the nut will screw onto the 1/8" pipe nipple and sandwich the rubber washers between the steel washers so there isn't any leaks. A piece of plastic tubing finishes it off.

The image on the right, you can see here a brake fluid residue left on the rubber washer, transferred from the end of the bottle, so the seal should be good enough to keep the brake fluid from leaking. But I'll have plenty of rags the first go round, just in case.

It became apparent that the fitting for the master cylinder cap would be a bit different than the one for the brake fluid jar cap. It needed to clamp securely to the Master Cylinder and not leak. Rather than try to fabricate something I headed out to Pick-N-Pull and got a Master Cylinder cap that I would modify. That way I was sure that it would fit, and seal tightly.

When I got the Master Cylinder cap apart, I could see that there was plenty of meat to clamp to, but it was very confined, so I would have to come up with something smaller.

I tried to put threads on a barb fitting, but it just collapsed. The only way I could get threads on a hollow bolt was to make one. It's not easy drilling a small hole in a small diamater piece of metal without a lathe, but here's how I did it.

I decided to use a piece of brass brazing rod, since it's a bit easier to machine than steel. First I threaded the outside of the 1/4" bar with 1/4 x 20 threads. I did this first, since the drilling a hole would weaken the brass, and it would probably collapse like the barb fitting did. Once threaded, it was clamped in a V block and then spot drilled with a center drill. Once the hole was started I followed the center drill up with a 1/8" and then 5/32" drill. I didn't want to go any larger than that, for fear of weakening the walls.

To attach the drilled bolt to the barb fitting would require some silver soldering. You could use regular solder, and it would work fine. However, silver solder is much stronger and I had an acetylene torch so I went the heaver duty route.

In order to get it positioned properly in the end of the barb fitting, I drilled a shallow hole, and then started a few threads. That way I could screw the threaded bolt in to get it started, and it would be centered, and not move when I silver soldered it. Then I had to enlarge the holes in the steel and rubber washers to fit the barb fitting and the threaded bolt. A little buffing on the threaded bolt/barb to pretty it up a bit.

And here's new Master Cylinder top, all put together, and ready to use. I think I'll use a large hose clamp to gently squeeze the top on the master cylinder to make sure it doesn't leak.

And here's what the whole thing looks like hooked up and ready to go, mounted to the hood latch. I couldn't find a small on/off valve, so keeping with the medical theme I just figured clamping some hemostats to the line would work just as well.

I got the Toyota OEM rear brake lines on Saturday, but there was a mixup and I got a Clutch Bolt instead of the Banjo bolts for the rear brake caliper. So I called the local Toyota dealer, and they didn't have it in stock, and wanted $6.50 for each Banjo bolt. The Toyota parts guy suggested that I call the local Lexus dealer to see if they had the parts. Yea sure, the Lexus dealer would probably charge $20.00 for the same part, or so I figured. Well what did I have to lose, so I called the Lexus dealer, gave him the part number and he said he had it in stock. When I asked how much, he said $5.50 each.

Hmmm, I could save a couple bucks driving down the street to the Lexus dealer. Who knew. I might be shopping at my local Lexus dealer for Camry parts from now on. Plus the Lexus dealer has a nice lounge with Coffee, Donuts and bottled water. Seems not may people that buy a Lexus work on them, so there is no waiting in line at the parts counter either.

Now I've got something that makes bleeding brakes a whole lot easier than the way I used to do it.

Maybe I'll bleed my brakes with every oil change. :D

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