Brake fluid changer question

I don't have a picture, but I'm sure many of you probably know what I'm talking about. I recently got to use (for the first time) one of those hand-pump vacuum-operated thingies that sucks brake fluid out of the caliper, instead of having an "assistant" inside pumping the pedal on command. It seemed to work OK, except for the fact that there was a constant stream of small bubbles (coming from in-between the tube and the nipple it turns out).

At the end of purging each caliper, I still had to put one of my kids (the slowest runner) inside and do the old "down... up.... down..... up...." to make absolutely sure the bubbles were not coming from inside.

My question is, was I just using an el-cheapo model, or do they all do that. I must admit, it DOES turn it into a 1-man job. However, I could never be 100% confident the little bubbles were "nothing to worry about".

Thanks, in advance.


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Mike Spencer
NC Region
ITA/7 RX-7 almost In-Garage
1990 RX-7 Convertible In-Driveway

I've never used the pump style pressure bleeder, so I can't comment on that.

But I do use speedbleeders on my SRX-7 and that has simplified the bleeding process for me. With the car on jack stands and the wheels off, I can bleed all 4 points in about 15 minutes. And I wind up with a firm pedal at the end. And I can do it by myself (a necessity).

Mike--Yes, they will all do that. The seal at the hose and the bleeder is the culpirt.

A couple other techniques & comments: The one-man/one way check valve devices work well, as do the speed bleeders. Both are great when changing a component or doing a flush.

Air pressure. Make a cap for your master's reservoir that seals air tight with an air chuck in it. Hook it up to low pressure air (5lbs. or less) and go around to each bleeder and bleed away. Obviously keep an eye on the fluid level at the master.

Joe's technique for one-man bleeding. Jam a stick between the back of the steering wheel and the brake pedal. Go bleed the bleeder. Repump and bleed the next wheel. Works well.

Cheers.

I used to use the same type, vacuuming it from the caliper. Two years ago I switched to the kind that has an air tank that fits onto the cap on the resevoir, you pump up the pressure in the tank, then bleed the caliper. Works great. I forget what it's called but I see it advertised in GRM.

Costs about $40?? Well worth it.

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Jeff L
#74 ITB GTi

[This message has been edited by JLawton (edited June 23, 2004).]

it's called a Motive Power Bleeder I believe

That's it!!! Thanks Chris!

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Jeff L
#74 ITB GTi

Just completed a install of speed bleeders including a speed bleeder at the master cylinder in the single line that goes to the rear. (1985 RX-7) Speed bleed the rear to a half down hard pedal. Take the master cylinder cover off & put the hose from the master cylinder speed bleeder into the master cylinder, crack the master cylinder speed bleeder. Speed bleed the fronts & the master cylinder speed bleeder allows full pedal (rear fluid travels back into the master cylinder.) while bleeding the fronts. A one person job in a few minutes.

Have Fun http://Forum.ImprovedTouring.com/it/wink.gif
David

make sure that air isn't sneaking in through the threads on the speed bleeders, though.

Mike - FWIW, I bought one of the vacuum pumps last year when I wanted to drain & refill the system, and have found it to work just fine. Yes, you do get the little bubbles, but I figured they were just coming in around the threads on the bleeder or the seal where the bleeder hose attaches. I did find that a little teflon tape on the bleeders helped to reduce, although not eliminate, the bubbles. Also, I make sure to close the bleeder before I relieve the vacuum on the system. I've bled the brakes with only the pump before each of my last 3 track days, and made it through 4 20-minute sessions each day with no noticeable fade. I think I paid around $40 for the pump.

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Earl R
Aspiring 240SX pilot

[This message has been edited by erlrich (edited June 25, 2004).]

See http://www.bmw-m.net/TechProc/bleeder.htm for a make-your-own, making approproptiate mods. I made one and use it once in a while. For instance one of my calipers has a different size thread bleeder screw, so it is speedbleeder-less.

I generally like the speedbleeders though.

When vacuum pumping, in a pinch, you can use some vaseline at the base of the bleeder screw to seal off incoming air. I keep a little and some q-tips with my vacuum pump.

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Steve
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