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I meant to write this up a while ago... Well, here it is now. Here's how I made a cheap simple vacuum brake bleeder that uses intake manifold vacuum to suck brake fluid:

Parts:

- A long piece of 3/8" hose. It needs to be strong enough not to collapse under about 10 psi of vacuum. I cut a 20' piece from a 50' pneumatic tool hose I bought for something like 8 dollars at Big Lots.

- A big jar with a metal lid. I used a 2-quart jar that I bought (filled with ridiculously bad dill pickles) for 99 cents from Big Lots.

- A shower flow diverter. I got lucky and found a cheap plastic one for 3 dollars at Big Lots. (Notice a pattern? )

- A short (1 or 2 inches) 1/2" galvanized steel pipe nipple. Several dozen cents at the hardware store.

- A 3/16" brass hose splicer. 1/4" would probably do too. Another several dozen cents at the hardware store.

- A brass 1/2" FIP to 3/8" male hose barb fitting. About a dollar from the same hardware store.

- Optional: a 3/8" hose splicer. I didn't use one but it could make it easier to use.

- A few feet of clear 3/16" vinyl tubing. Another buck or two from the hardware store.

- Miscellaneous stuff: solder, flux, a torch, zipties, hose clamps, Teflon tape.

Assembly:

- Empty the jar of any contents. Wash it out and dry it out.

- Cut two holes in the lid of the jar, not too close to the edges. One hole should be just big enough to fit the 1/2" nipple through (ideally you'd have to thread the nipple in) and the other should be just big enough to fit the hose splicer in.

- Put the two fittings in, and solder them into place. I used Goop at first, but the brake fluid actually ate through the Goop. Soldering seems like the sensible way to go and is easy to do. Just make sure not to burn the edges of the gasket that's built into the underside of the jar lid. The easiest way is to pour some flux around the base where the fitting attaches to the lid, then wind some wire solder around it a few times, and then apply heat with a propane torch at the top of the fitting. The heat will flow down the fitting until it activates the flux and melts the solder. If you did it right, it'll nicely tin the fitting and the lid.

- Let the lid cool before you touch it.

- Cut a length of vinyl tubing as long as the jar is tall, and attach it to the underside of the 5/16" fitting. Use a ziptie or hose clamp if necessary to hold the tubing in place.

- Put the lid on the jar.

- Thread the flow diverter onto the 1/2" pipe nipple sticking out of the top of the lid. Use Teflon tape to seal the threads.

- Thread the 1/2" FIP to 3/8" hose barb fitting onto one of the diverter valve's outlets. Again, use Teflon tape.

- Attach the remainder of the vinyl tubing to the top of the 5/16" fitting and attach the 3/8" hose to the 3/8" barb. Use zipties or hose clamps if necessary.

Usage:

- Attach the 3/8" hose to the intake manifold. I unplug my brake booster hose from the manifold and put the 3/8" hose in its place. If you use a 3/8" hose splicer you could unplug the brake booster hose from the booster instead of the manifold and attach there if you wanted.

- Turn the diverter valve's handle so that the jar is open to atmosphere (i.e. the "flow" is "directed" towards the end that has nothing attached).

- Start the engine. It may be helpful to raise idle speed by wedging the throttle open with a quarter or something.

- Seal the threads of the bleeder screw on whatever you're bleeding. If you have a speed bleeder in there it should already have sealed threads. If not, remove the bleeder screw, clean the threads off, properly apply Teflon tape to them, and reinstall the bleeder. You should only have to do this once.

- Fit a closed-end or flare nut wrench over the end of the bleeder and then attach the 5/16" hose.

- Turn the diverter valve fully in the other direction, allowing the engine to depressurize the jar. The engine may stumble for a few seconds when you do this. Wait a few seconds for the jar to depressurize.

- Remove the brake master cylinder cap. If desired, pull out as much fluid as you can with a turkey baster or syringe and replace with new fluid. In any case, fill the reservoir up to the top.

- Loosen the bleeder screw. As soon as you get it open air and fluid should start flowing out into the jar. Make sure the fluid level in the master cylinder never falls below the low mark.

- Once you're satisfied with that bleeder, tighten the bleeder screw back down, switch the diverter valve (you'll hear the vacuum release to atmosphere), and remove the vinyl hose from the bleeder.

- Repeat with any other portions of the system you may need to bleed.

You might be able to get away without the whole diverter valve setup, but it does allow you more control over the vacuum. If you have speed bleeders you can use the diverter valve to start and stop bleeding. And, you can allow the engine to depressurize the jar before opening the bleeder screw.

You might want to reset your ECU after you're done with this, since the temporary vacuum leak might adversely affect its fuel trims.

[edited to correct the vinyl tube size]

Woah, nice write up.

What is a shower flow diverter?

Oh, and Big Lots = the best.

It's a little valve that you normally stick between your showerhead and the pipe in the wall that allows you to also connect a handheld shower head:

Wow, here's a cheap one:

http://www.acehardwareoutlet.com/produc ... id=4104220

Nice Vikash.

Thanks.

It makes brake fluid service so easy.

The only part of the process that I could imagine possibly having ill effects might be the fact that the engine consumes some brake fluid fumes. I don't think it'll be a problem, though; in fact, it might clean the heads out a little!

Oh, and I left this out in the first post, but be sure not to let fluid level in the jar get too high. You don't need your engine consuming ingesting brake fluid.

coool!! got any pics?

This is AWESOME!!

Josh - Well, I lent the one I made to my brother so it's hundreds of miles away. I'll see if I can draw a little diagram though.

boostjunkie - Thanks! It was funny when I came up with it. I had originally just built one that used a refrigerator compressor, but I was trying to think of a vacuum source someone was more likely to just have lying around. I glanced down at the manifold pressure gauge on my center console at it said my engine was pulling 20 inches of vacuum.

I was worried at first that manifold vacuum wouldn't be strong enough, but it worked well for me. Like I said, it helped to increase idle speed.

vrg3 wrote:Josh - Well, I lent the one I made to my brother so it's hundreds of miles away. I'll see if I can draw a little diagram though.

boostjunkie - Thanks! It was funny when I came up with it. I had originally just built one that used a refrigerator compressor, but I was trying to think of a vacuum source someone was more likely to just have lying around. I glanced down at the manifold pressure gauge on my center console at it said my engine was pulling 20 inches of vacuum.

I was worried at first that manifold vacuum wouldn't be strong enough, but it worked well for me. Like I said, it helped to increase idle speed.

It's not that far from me

I'm always amazed by your ingenuity. I would never have thought to use the engine as a vaccum source! Not to mention using the brake booster for brake bleeding. GENIUS!

Hey, yeah, I didn't make that connection in my head -- we're using the brake booster fitting for brake bleeding!

If you want to drop by my parents' house and take some pictures, feel free . The unit is actually probably right on the garage floor next to the Supra which is on jackstands with its transmission out. Feel free to borrow it if you want too.

The Supra on jackstands with the transmission out?

How would that be useful?

We had to leave the car halfway through a clutch replacement.

Oh, and let me clarify -- Jason, by "borrow it" I meant borrow the bleeder, not the Supra.

I just made another one of these today since it was easier than trying to find someone to help me bleed the brakes on the Mazda 626 I was working on... I realized that I made an error above. The vinyl tubing should be 3/16" inner diameter. The tubing I was using had a 5/16" outer diameter, which was why I got confused.

heh petridish and I were talking about this. He was saying something about there'd still be old fluild left in the abs module. He also said the dealer can hook up something that'll hold the piston open or something to let the fluid out of the abs module. Is there anyway for us to do this?

About the dealer-specific tool thing, I think that applies to later versions of Subaru ABS. The Select Monitor can talk to the ABS computer and tell it to do stuff. I believe the term is sequence control. That's not true for our cars, though.

Bleeding with ABS depends on your ABS system, I think... recall there are three types:

http://bbs.legacycentral.org/viewtopic. ... 3&start=10

The regular Nippon one, which is the most common, has a pair of bleeder valves on it to use to bleed it. The FSM says that to bleed the brakes on a car with the regular Nippon system, you bleed the rear bleeder on the ABS unit, then the front right caliper, then the rear left caliper, then the front bleeder on the ABS unit, then the front left caliper, and finally the right rear caliper.

I don't know for sure whether or not that gets all the old fluid out of all the nooks and crannies of the ABS unit, but I know that when I installed an ABS unit that had sat for untold lengths of time on a junkyard's shelf, and then sat in my garage for a few months, I bled in that order. Then, when I activated ABS for the first time, I checked my fluid and it was just as gin-clear as it was before. I dunno.

I couldn't find any explanation in the FSM about dealing with ABS systems that don't have the bleeder valves.

If I were just changing brake fluid, I'd do a complete bleeding at all the calipers, then go out and activate ABS a few times, and then do bleed 'em again. Repeat if desired.

I suppose we could whip together a little thing to plug into the ABS unit under the hood and cycle its motor and solenoids, but it hardly seems worth it...

Here's a few pics of one of the VRG3 Vacuum Bleeders:

photodump again? bleh

I use your Gallery for most of my stuff Hardy. I just want to keep my Gallery for pictures pertaining to Subarina.

Thanks for posting those up, Matt... hopefully people can get a better idea of how it goes together.

Can't you own multiple galleries on THAWA's site?

I have one of the commercial pump-style bleeders that also allow one-man brake bleeding. One caveat: several of my friends who are auto-X and SCCA junkies have said that bleeding this way is nice, but should be followed by a round of manual bleeding at the calipers, with a pedal-pushing helper. They say that old brake fluid can hide during the vacuum process, since the caliper pistons are not moving. Basically the new fluid short circuits past old fluid and out the bleeder.

That actually makes sense to me, but probably only important if you are racing or have really bad old fluid.