911 Rod

Hmmm
So flushing every 2 years and bleeding before Driver's Ed (2 weekends/year) is sufficient?
I don't actually use my brakes much at Mosport.
Middle run group, signed off, street tires.
They should sell little bottles for the cheapos that only want to bleed a little.

r911

Ate Super Blue is $17 for a full can. The safest thing to do is recycle the old stuff and get a nice new, fresh can.

That said, even tho you are in Ont., if the can is really sealed completely the absorbtion of water vapror cannot physically be greater than the amount of water that is the air space in the can. It won't be much. At 20 oC, and at saturation (100% RH) there will be ~ 17.7 grams of water in 1 m3 of air. The air space in the can is probably about 1/4 litre. The brake fluid remaining in the can is xxx grams. So, do the math -- it is quickly obvious that only an infintesimal amt. is going into the brake fluid -- and that is not at equilibirum, instead it assumes ALL the water goes in from teh air space.

If, OTOH, the can is not sealed, then the water vapor absorbtion will approximate that of the fluid in the reservoir, which is open to the atmosphere.

So don't worry about it.

KC911

Thank you all for your input on this interesting (to me) topic. Rod 911, please do NOT follow MY advice, as several others (who know far more about these cars than I ever will) have given you their expert opinions (even though experts some times disagree). I agree whole heartedly that the track is not the place to take an unnecessary risk. That being the case, evaluate the points that have been made in this thread and use your best judgement. Logically, I think I fully understand the issues and will do the same. Thanks again everyone!

ps: I would be grand if Super Blue were available smaller, sealed containers (for bleeding) and eliminate the debate altogether

Keith

Edward

What for, so ATE has the opportunity to make less money??

I asked a clerk at Costco once why they didn't have a 10-item-or-less Express line. She answered with the question, "you mean so Costco can encourage you to buy only the few items that you actually need?" ...best answer I've had in a long time!



Edward

john70t

Couldn't the water be heated/boiled out using a stainless pan? (for a daily beater)

wholberg

I never use old brake fluid either. I bite the bullet and buy several small containers so that when I bleed the brakes I can just throw away any unused remainder. I would just top off the reservoir if I were just going to drive it locally and I intended to bleed the system within the next month or so. I definitely would not do it for a track run. I would open a new container and just flush the entire system.

KC911

What size do you refer to when you say 'small containers', and which brand? AFAIK, ATE Super Blue only comes in 1 litre cans. If you're referring to the smaller containers that the typical auto parts stores might carry...from my experience, they have much lower WBP (wet boiling points) than ATE, so I'm not sure that's any better than 6 month old ATE. And I wholeheartedly agree that a flush of the whole system is best prior to a track event. Thanks again everyone!

Keith

g-50cab

This is one reason why I like the small Motul 600 cans. Small enough to flush the system, small enough to use the whole can - not big enough where I am tempted to close and reuse at a later date. In the whole scheme of things - why cut corners on something that can potentially so important.

And Keith - check out the wet and dry boiling points of motul 600 - nice numbers compared to ATE.

KC911

I will Jeremy, thanks! What's the size of the Motul 600 cans, and where do you get yours from? I'm due for a flush/change, so this thread is timely...

Keith

ps: Since I've got a 1 litre can of ATE on hand, is it OK to mix fluids? i.e. Do the flush/change with ATE (to use it up), and then bleed later with Motul, etc.?

r911

Yeh, bite that $17 bullet.

Motul is hard to find many places -- when I finally found a place in town here that could _order_ the Ate, I thought I was buying a French Burgundy or something. Motul was out of the question...

KC911

OK, I'm convinced....I'm really NOT that cheap

g-50cab

$14.95 per 1/2 litre -

http://www.raceshopper.com/motul_brake_fluid.shtml

Some motorcycle race shops carry it - 594f dry boiling point 421f wet

KC911

Thanks Jeremy! And Randy, I just checked Pelican, and they have, ATE Gold for 13.00 and ATE Blue for 13.75. I guess I'll just wash my car with the unused brake fluid from now on

Keith

g-50cab

Oh - and I usually keep a litre of ATE blue on hand so I know when I flush the entire system out - pump the resevior -

Steve Weiner-Rennsport Systems

Hi Keith:

I didn't test a whole range of "aged" fluids in their respective containers, nor did I compare fluid in the reservoir compared to what cam out of the calipers since I was demo'ing this instrument for a short time.

Based on what I've seen in normal coloration changes between the reservoir and what came out of the bleeders, temperature changes exacerbate the absorption rates here. REALLY ignored fluid looks the same (dark brown) whether its in the reserver or in the calipers,....

One should take careful note about the brake fluid recirculating systems that Nextel Cup cars use to push the fluid from the MC to the calipers and back at each pump of the pedal. Its pretty damned ingenious to contain fluid temps in the calipers and allow it to cool off a bit,.....

Just MHO;..........Changing/flushing the brake system at least twice a year for street-only cars and before every track event simply constitutes good preventative maintenance and its a minor cost compared to fuel, oil & tires. For folks on a limited budget I'd suggest getting a few friends together and making a case buy on the fluid of choice to reduce costs here.