Brake fluid questions ?
Thread Starter
Team Owner
Joined: Jan 2004
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From: Boston MA
St. Jude Donor '06-'07-'08,'12-'13
Brake fluid questions ?
Can you mix DOT 3 and 4 ?
How do you completly flush system saftely?
Does brand new brake fluid go bad whaen it sits in a brand new sealed container for a long period of time ?
Thanks
How do you completly flush system saftely?
Does brand new brake fluid go bad whaen it sits in a brand new sealed container for a long period of time ?
Thanks
Melting Slicks
Joined: Jan 2002
Posts: 2,708
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From: Billings MT
Dot 3 and Dot 4 will mix, but GM does not recommend it except in an emergency type situation. They definitely say if the vehicle uses the new Dot 4 DO NOT change it back to Dot3 . There is no actual shelf life for brake fluid if the container is sealed. If it has been sitting in the garage in freezing and hot weather for 10 years I would probably recommend you go buy new instead of using it. To flush the brake system completely and be sure is easiest with a power brake bleeder, but can be done the old fashioned manual way. It just takes longer.
Bob
Bob
Race Director
Joined: Sep 1999
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From: CONCORD NC
brake fluid is hygroscopic, meaning it really absorbes water, which kills it's boiling point. Not really a problem for a street car, but kills its high temp stability at the track.
You can flush the system easily in the old fashioned way, by bleeding. You only need to purge the ABS unit if you get air in it, as normal bleeding will push the old fluid out, just cant get air bubbles out.
As above, since the only issue with fluid is absorbing water, and UNOPENED sealed container will last a long time. If you open it, use a little, and put the lid back on, it will not be as good when you re-open it.
Again, for street use, this isn't a big deal.
You can flush the system easily in the old fashioned way, by bleeding. You only need to purge the ABS unit if you get air in it, as normal bleeding will push the old fluid out, just cant get air bubbles out.
As above, since the only issue with fluid is absorbing water, and UNOPENED sealed container will last a long time. If you open it, use a little, and put the lid back on, it will not be as good when you re-open it.
Again, for street use, this isn't a big deal.
Race Director
Joined: Aug 2005
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From: Hudson WI
NCM Sinkhole Donor
I thought I would save money once and bought a gallon of brake fluid. Never buy a gallon of brake fluid (for home use), as stated earlier, brake fluid atttracts moisture, so less is more.
Race Director
Joined: Mar 2005
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From: Austin Texas
What about the Castrol GTLUMA brake fluid that states on the label "exceeds all DOT 3 and DOT 4 SPECS"? The label further states; "recommended for ---- hydraulic drum and disc braking systems and hydraulic clutches requiring DOT 3 or DOT 4.
I'm using it in the brake and the clutch. A 12 oz can fills both master cylinders after a "turkey baster" change.
I'm using it in the brake and the clutch. A 12 oz can fills both master cylinders after a "turkey baster" change.
Team Owner
Joined: Sep 2003
Posts: 43,084
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From: Raleigh / Rolesville NC
Originally Posted by haljensen
What about the Castrol GTLUMA brake fluid that states on the label "exceeds all DOT 3 and DOT 4 SPECS"? The label further states; "recommended for ---- hydraulic drum and disc braking systems and hydraulic clutches requiring DOT 3 or DOT 4.
I'm using it in the brake and the clutch. A 12 oz can fills both master cylinders after a "turkey baster" change.
I'm using it in the brake and the clutch. A 12 oz can fills both master cylinders after a "turkey baster" change.
I use a 50cc Syringe to suck out the old fluid from the MC. Less messy then the turkey baster.
Once a bottle of brake fluid is opened, use it and toss the remainder. in 2 or 3 days that last remaining 1/4 bottle will be contamiated.
Melting Slicks
Joined: Nov 2004
Posts: 3,064
Likes: 6
From: Pinellas Park Florida
Originally Posted by davidfarmer
brake fluid is hygroscopic, meaning it really absorbes water, which kills it's boiling point. Not really a problem for a street car, but kills its high temp stability at the track.
You can flush the system easily in the old fashioned way, by bleeding. You only need to purge the ABS unit if you get air in it, as normal bleeding will push the old fluid out, just cant get air bubbles out.
As above, since the only issue with fluid is absorbing water, and UNOPENED sealed container will last a long time. If you open it, use a little, and put the lid back on, it will not be as good when you re-open it.
Again, for street use, this isn't a big deal.
You can flush the system easily in the old fashioned way, by bleeding. You only need to purge the ABS unit if you get air in it, as normal bleeding will push the old fluid out, just cant get air bubbles out.
As above, since the only issue with fluid is absorbing water, and UNOPENED sealed container will last a long time. If you open it, use a little, and put the lid back on, it will not be as good when you re-open it.
Again, for street use, this isn't a big deal.
How do you purge the ABS unit? Is this a problem with GEm's ABS system?
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From: Raleigh / Rolesville NC
I use a Motive power bleeder with 10-12 psi of pressure. That is enough to push the new brake fluid though the ABS system.
or just pump the brake peddle severl times to get the pressuer up, then hold the peddle down( have neighborhood kid do this) as you bleed each caliper, that also is enough to open the ABS.
a Tech II is not needed, vacuum pumps are not that great either.
or just pump the brake peddle severl times to get the pressuer up, then hold the peddle down( have neighborhood kid do this) as you bleed each caliper, that also is enough to open the ABS.
a Tech II is not needed, vacuum pumps are not that great either.
Melting Slicks
Joined: Nov 2004
Posts: 3,064
Likes: 6
From: Pinellas Park Florida
Originally Posted by AU N EGL
I use a Motive power bleeder with 10-12 psi of pressure. That is enough to push the new brake fluid though the ABS system.
or just pump the brake peddle severl times to get the pressuer up, then hold the peddle down( have neighborhood kid do this) as you bleed each caliper, that also is enough to open the ABS.
a Tech II is not needed, vacuum pumps are not that great either.
or just pump the brake peddle severl times to get the pressuer up, then hold the peddle down( have neighborhood kid do this) as you bleed each caliper, that also is enough to open the ABS.
a Tech II is not needed, vacuum pumps are not that great either.
Race Director
Joined: Dec 2005
Posts: 11,298
Likes: 957
From: Carlsbad Ca
Vacuum systems will cavitate air from around the threads of the bleeder screws. You will have to bleed the calipers the old fashion way once the M/C is primed. The vacuum Will pull the fluid fast though and that can help with bleeding.
Always do it in this order: Right rear,left rear,right front,left front.
Always do it in this order: Right rear,left rear,right front,left front.
Last edited by NORTY; Mar 6, 2006 at 11:29 AM.
