Question on Brake fluid from Dot 3 to newer formula like in a new car.

Author Topic: Question on Brake fluid from Dot 3 to newer formula like in a new car.  (Read 1093 times)

Offline Kevin71

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I want to change the brake fluid to from the old dot 3 to newer stuff that doesn't eat up the paint and doesn't absorb moisture.  I live in Fl.  Do you just have to drain the system and all the calipers.  I have all wheel disc.  Or do you have to run some cleaner thru the system.  Maybe it's just to much trouble.  But thought I would aleast explore the idea.  I mean would residue of the old fluid in the system  cause a problem.  Should I drain then fill and bleed a bunch to get out all the old stuff.  Any ideas?




Offline 67vertman

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Re: Question on Brake fluid from Dot 3 to newer formula like in a new car.
« Reply #1 on: December 29, 2013 - 08:52:15 PM »
I did this swap when I went with my 4 wheel disk.  I drained all the fluid from the brake reservoir, lines and clippers.  Then I left the system open for a little while to air it out (evaporate).  Then I refilled my system and bleed the brakes.  I ran about half an extra bottle through the system.  It has been one year with no issues.  Some sites say you need to run denatured alcohol through the system, others don’t.   



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Offline Katfish

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Re: Question on Brake fluid from Dot 3 to newer formula like in a new car.
« Reply #2 on: December 29, 2013 - 09:23:31 PM »
I'm switching over and asked Eburg about this, he replied there is no reason to flush with alcohol.
Just drain the old stuff out and bleed all 4 corners until it runs purple and it's good to go.

Offline Chryco Psycho

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Re: Question on Brake fluid from Dot 3 to newer formula like in a new car.
« Reply #3 on: December 29, 2013 - 09:52:17 PM »
I would remove the cailper Turn it upside down & drain all of the old fluid possible out of the system just in case DOT5 in not heavier then the DOT3 fluid

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Offline anlauto

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Re: Question on Brake fluid from Dot 3 to newer formula like in a new car.
« Reply #4 on: December 29, 2013 - 10:38:13 PM »
Once you feel you got all the old stuff out, you could fill the master with brake cleaner and pump that through the entire system.  :dunno:

I use Dot 5 in all my restos :2thumbs:
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Offline Kevin71

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Re: Question on Brake fluid from Dot 3 to newer formula like in a new car.
« Reply #5 on: December 30, 2013 - 10:13:25 AM »
Thanks.  I am going to put a set of wilwood 6 piston on the front and thought it would be a good time to change the whole system.  I have the ssbc on the fronts now and have never worked well but they came on the car so I don't know what kind of shape they are in.  They probably need rebuilding.  Anyway thanks alot.

Offline Cuda Cody

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Re: Question on Brake fluid from Dot 3 to newer formula like in a new car.
« Reply #6 on: December 30, 2013 - 10:28:04 AM »
FYI, do not use DOT 5 with ABS.
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Offline Kevin71

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Re: Question on Brake fluid from Dot 3 to newer formula like in a new car.
« Reply #7 on: December 31, 2013 - 02:02:57 AM »
No don't have no ABS just big with light touch.