[Trak Ratt]

I had an epiphany while flushing the SC brakes Sunday after finally installing the Carrera calipers. We (me & Black Talon) were waiting for the 944 owner to show up and tell us where he hid the ‘44s pan gasket. I was industriously pumping away on my Motive Power Bleeder when it occurred to me that there was probably a better way.

The Motive is really handy but the constant pumping is seriously lame. After thinking about it I decided to put a valve stem in the side of the bottle & use my small track air compressor to charge the bottle. Alas, the only metal one I had was unavailable, so I took off the hose and master cylinder adapter cap and hooked it directly to the little compressor. What a difference

The Motive makes power bleeding easy, the compressor makes it even faster. You do have to add fluid more often, but then you don’t waste any. A plus at the track. I guess I could use my track air bottle instead of the compressor too. Come to think about it, I may not even modify the bottle.

Note: I had not actually put any fluid in the bottle since getting it. Not totally sold on mixing fresh brake fluid with what ever is left in the bottle. Anyone have any thoughts on that

[racer]

Originally Posted by david riley

Note: I had not actually put any fluid in the bottle since getting it. Not totally sold on mixing fresh brake fluid with what ever is left in the bottle. Anyone have any thoughts on that

Not a fan of mixing, but what's a guy to do when his brake fluid drops over the course of along weekend (due to pad wear, not a leak) and need to top off the ol' system)

Additionally, if your concerned, you can always check to see what the "wet" boiling points are of various brake fluids and make sure you don't heat up your brakes to that temperature :P

[cmartin]

Good thinking David. I've used another brand bleeder that has a male fitting for an air hose on it. The only issue is to make sure your regulator goes low enough to not blow the brake system to pieces.

[Marc A]

FWIW Brake fluid is hydroscopic so I rinse out the bottle with water and blow air through the cap and into the bottle to get the line clear, then just let the bottle air dry until the next bleed.

I know that can't be done at the track, but the only fluid that I have seen (as well as the motive) is ATE gold or blue.

[Trak Ratt]

[quote="racer"]

Originally Posted by david riley

Not a fan of mixing, but what's a guy to do when his brake fluid drops over the course of along weekend (due to pad wear, not a leak) and need to top off the ol' system) :P

Actually, I leave my extra fluid in the brake fluid can, only adding what is needed to the master’s reservoir. The can has a pretty good cap seal, though I don’t keep a partial can long.

CM; Though small the track compressor has a regulator and gauge on the exhaust side.

[Jazzbass]

I've thought about doing this to my power bleeder, but never did as my logic is that going back to pump the handle gives me a chance to check on the fluid level. I can see myself getting distracted and letting the compressor blow all the fluid out of my system .

[BobNovas]

Sez Marc -

FWIW Brake fluid is hydroscopic so I rinse out the bottle with water and blow air through the cap and into the bottle to get the line clear, then just let the bottle air dry until the next bleed.

Am I being paranoid? I would never have thought to put water any where near anything to do with brake fluid for precisely the reason that brake fluid is hydroscopic.

[Trak Ratt]

The compressor has a small tank, so when it reaches 20 PSI or so, I shut it off. Eventually, I’ll have quick release fittings added. Till then I have to release the pressure on the tank to take off the master cylinder top to add more fluid anyway. That’s why I used the small compressor, less spool-up. Even so it’s still easier than “pumping”
Just an alternative method to do a tedious job we all seem to be doing a lot. The Motive web site has just the adapter with a male fitting on the end of the hose for $15.
The real “brake” through will be a system solution to do this without taking off the wheels 8)

[Jase007]

I am not sure how much fluid you are running through the Motive but having changed from ATE Blue to yellow to blue ...etc...a few times, it doesn't take much pressure and or many pump-ups to push the newer (colored) fluid through all the lines in my experience.

I like Kurt's in car pressure bleeder system. Like a small motive (two plastic containers with fluid) and you add air-pressure to a fitting (via compressor or tank).

Jase

[Vicegrip]

(Caution! One man's opinion to follow, hold nose and squint)

It seems to me that 20 sec of pumping up the Motive to 15 psi is less work that stopping, checking, releasing the pressure, adding fluid, repressurising 4 or 5 times during a flush. You can peform a 1 quart flush on one pump cycle. 15 psi is the max I use. The hoses running from the fluid tank to the MC are not pressure lines and can pop off if overpressurised.
To me the best part about using a Motive is that you can run a quart or two without stopping or risking running the fluid low and stuffing air in from the front end. Not putting fluid in the tank defeats this but does save on the clean up time but air in the MC is a royal pain in the a$$ to clear.

The tire stem on the tank is an great effort saver. If you do so, 1. drill a somewhat smaller than in a rim hole as the plastic is thinner than a rim. 2. add it right next to the fill neck where the tank plastic is thicker. Be sure that the compressor air and your lines are dry or you will spray H2O into the tank while filling. I have a bunch of little metal air valves that will fit if anyone needs one. They are for HVAC but will clamp to the thin plastic of the tank well. They seal with an O ring and bolt on tight.

Yes, you can clean the bleeder with H2O. Brake fluid mixes well with water. I wash with water and blow out with air or flush with a rinse on Brake Kleen. You can also clean with just Brake Kleen if you want. Clean it out every time! I also dry off the pump and pump it some to be sure there is no water in it as well. You can leave fluid in the tank if you plan to use it in a month or so but the hose is another mater. I found that the hose gets funky if fluid is left in it so I just clean everything up.

Or you can add 2 16 oz fluid bottles and a small camp stove to pump to your brake system and do away with all of the above. Just fill both bottles to top with fresh fluid, pump it up and blow down to half full. Done.

EDIT. Jase, I posted without seeing your post. I use a small mounted camp stove fuel bottle for pressure that weighs 2 or 3 oz total. When (if) I have some time I might start making retro fit kits for sale. They would be a self contained bolt on mod (This means you RL)and do away with the dribbling overflow tube too.