I'm going to make a pressure bleeder out of a super soaker!

[DYL]

So I kind of want a pressure bleeder, but I am leery of putting brake fluid in it, since it can damage paint. I don't need much fancy hosing to dispense the fluid, I just need to pressurize the system. I also have an old super soaker in the garage. It is a very simple model: screw on plastic bottle, tubing, pump.

Preliminary design: hacked off barrel, pressure gauge in tank, new/extended tubing, PVC end cap for reservoir, tire stem valve on cap for depressurization. NPT or other barbed hose fittings for the connections. Rope to hold down trigger when needed.

This is why the super soaker is the superior option:
-the trigger allows me to hold pressure even with the cap off, allowing quicker refilling
-the pump is unlikely to be able to reach dangerous pressures
-I have it already
-compact

Possible complications:
-strange tubing size
-not enough pressure (but I think it goes up to 60 psi, which is actually too much)
-tank too small → excessive pressure drop (my greatest concern)

This is kind of a slow project, but I have already ordered a Schrader (tire stem style) valve with NPT fitting and a pressure gauge. The price of those 2 parts is about $9.

[bmwdirtracer]

So I kind of want a pressure bleeder, but I am leery of putting brake fluid in it, since it can damage paint. I don't need much fancy hosing to dispense the fluid, I just need to pressurize the system. I also have an old super soaker in the garage. It is a very simple model: screw on plastic bottle, tubing, pump.

Preliminary design: hacked off barrel, pressure gauge in tank, new/extended tubing, PVC end cap for reservoir, tire stem valve on cap for depressurization. NPT or other barbed hose fittings for the connections. Rope to hold down trigger when needed.

This is why the super soaker is the superior option:
-the trigger allows me to hold pressure even with the cap off, allowing quicker refilling
-the pump is unlikely to be able to reach dangerous pressures
-I have it already
-compact

Possible complications:
-strange tubing size
-not enough pressure (but I think it goes up to 60 psi, which is actually too much)
-tank too small → excessive pressure drop (my greatest concern)

This is kind of a slow project, but I have already ordered a Schrader (tire stem style) valve with NPT fitting and a pressure gauge. The price of those 2 parts is about $9.

I wouldn't let it near my car -- but, hey, if you invite some friends over, you can supersoak them with brake fluid....

[MarcoZandrini]

Get a vacuum unit to bleed the brakes. There's no way to introduce air into the system, and you can use it remove power steering fluid, brake fluid, etc.

[midevilish]

Lol

[jmo69]

Just buy the BavAuto unit, when it's on special you get a catch bottle with it. I've got one and love it, now I used my Mityvac just to drain the reservoir.

[bmwdirtracer]

my secret recipe: Pressure bleeder on one end, vacuum bleeder on the other.

There's really no reason to reinvent this wheel.....the currently available systems are inexpensive, and work very well.

[DYL]

I admit I could buy one, but I want to do this for fun. I have a supersoaker that is already messed up, so I'd use that one.

If you look at the videos DIY pressure bleeder, you'd notice that the motive and bavauto bleeders are essentially pesticide sprayers with some extra stuff attached. You could theoretically pour some brake fluid into a sprayer and attach a cap to the hose, and pump it up...

If the supersoaker doesn't work, I'd probably get a sprayer. Only problem is that it would be bulky. I don't need capacity because I would not have brake fluid in it.

[jmo69]

The nicest thing about the BavAuto unit is the coupler on the proper size reservoir cap and the air release valve on the pump. I understand the desire to build your own, I have 2 devices for filling transmissions and difs made from PVC pipe and airline fittings. Much easier than hand pumps.

[DYL]

I've planned my own pressure release: a Schrader valve in the cap. It will also serve as a way to independently check the pressure. A fitting would be nice so that I don't have to worry about twisting tubes. I will have to see what diameter tubing I'll be using.

I'd like to hear more about that transmission filler you made. Only problem is, it's a pain to clean out fluid/oil. My harbor freight hand pump did 2 transmissions and 2 diffs before it started leaking and I got tired of cleaning it. Rapidly pumping diff fluid kills them.

[DYL]

Finally got some time to work on this thing. Inside the supersoaker, it is really just a bunch of tubing and fittings, along with a blow molded bottle, shaped to look vaguely gun-like:

It uses 1/4" tubing with .170 ID. I got 6 feet of it and put it where the nozzle used to come out (it broke already, so I trimmed it a bit). Drilled for a pressure gauge and the fittings. The threads for the gauge leaked, so I put on some Teflon tape. This is what it looks like so far:

I am using the Help! cap recommended by other DIY guides (nearly all the amazon reviews reference homemade pressure bleeders for E36, etc.) Put in some RTV because those cheapskates didn't include a gasket, and actually put a groove into it that would have prevented a good seal. Drilled into it for a hose barb and Schrader valve.

[bmwdirtracer]

I'll only say that I have tried to create a smoke machine - twice. That's because a smoke machine costs $1000-2500, (Then I bought a smoke machine)

I'm a racer, and a professional BMW tech, and I've worked in a specialist custom metal shop, for years; so I'm not bad at creating things. But one thing I've learned during my custom work: it almost never pays to reinvent something for which there's already a very good and inexpensive solution.

There are $50 or $60 pressure bleeders, with guage, screw on caps, and ease of use, with little or no chance of blowing brake fluid all over your expensive paint. And you've spent hours and hours creating a child's toy with springs and triggers and plastics that have never been tested against brake fluid, an exceptionally destructive fluid.

Duck Fat.

[DYL]

That's why it'll be running dry. No fluid will be in it. I'll probably get a commercial one some day, but it's been a lot of fun making this

[DavidD123]

Pretty cool! Neat idea and I applaud you in continuing with it. One concern I have is the seals in the super soaker might not like brake fluid as they were never intended for this application.

Good luck! Keep us updated!

[DYL]

I have absolutely no faith in the super soaker's brake fluid resistance, or even its ability to dispense fluid without bubbles. That's why it will only have air inside it. The air will pressurize the reservoir, and fluid will need to be periodically refilled. I can remove the cap without losing pressure by releasing the trigger.

[DYL]

Note: trigger is a good idea, in theory, but terrible in practice. A sudden release of pressure from the hoses tends to splash fluid around. RTV doesn't react well to brake fluid, and started to come off of the cap. The Help! cap has a slot in it, so fluid started coming out. Good thing I only gave it a little burst of air.