Changing Dot 4 to 5?
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Joined: Sep 2009
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From: SE Michigan
Reason why good?
But beyond that, Harley designs its systems and sets out its requirements and there are bad warnings about not using the right brake fluid. Given that, whats the payoff from switching?
Much more knowledgeable people will chime in with technical reasons, but with all the great ways to tinker with your bike, even if you could get away with it, I just dont see any payoff from doing it.
But beyond that, Harley designs its systems and sets out its requirements and there are bad warnings about not using the right brake fluid. Given that, whats the payoff from switching?
Much more knowledgeable people will chime in with technical reasons, but with all the great ways to tinker with your bike, even if you could get away with it, I just dont see any payoff from doing it.
Last edited by Keithhu; Apr 12, 2012 at 07:36 PM.
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From: earth
Yes you can, you have to completly purge the system, thoroughly clean everything, and replace all orings, gaskets, and rubber seals. The only reason to do it is to have a paint safe fluid. Whole lotta work for not much return.
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DOT 5 will net you a few more degrees of boiling point (a bit higher temp is needed to make it boil) over DOT 4... but DOT 5 is slightly "compressible" as it is silicone based vs polyethylene glycol based as is DOT 3, DOT 4 and DOT 5.1.
All in all, you could do the switch over if you REALLY wanted to, but is highly advised against since the entire brake system was designed to be bathed in polyethylene glycol and not engineered to be subjected to silicone based juice.
All in all, you could do the switch over if you REALLY wanted to, but is highly advised against since the entire brake system was designed to be bathed in polyethylene glycol and not engineered to be subjected to silicone based juice.
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Tourer
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From:
If you don't get all the dot 4 out it will gel with the dot 5 and you will end up having to rebuild your caliper,master cylinder and have to replace your line. If you do change it make sure you change the master cylinder cover to dot 5. If your bike goes in for service at a dealer it could happen all over again.
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From: ID Ho
DONT DO IT YOU WILL DIE!!!
The pay off is DOT 5 doesnt eat paint, the reason behind the change to DOT4 is that 5 will airate in the ABS pump. No ABS go for it.
You need to flush the whole system with an alchohol type brake cleaner, I did the rear on my 07 SG with no problems, sucked all the 4 out through the caliper bleeder, filled the master with alcohol and sucked through several times then filled with DOT 5 and sucked 2 or 3 masters full through then finished up bleeding the system. Did the same thing on a car that had DOT3 in it only all I did then was pulled 5 through until it came out purple at each bleeder, didnt flush the system otherwise. Drove that 4500 lb car another 10 years with no brake issues!
The pay off is DOT 5 doesnt eat paint, the reason behind the change to DOT4 is that 5 will airate in the ABS pump. No ABS go for it.
You need to flush the whole system with an alchohol type brake cleaner, I did the rear on my 07 SG with no problems, sucked all the 4 out through the caliper bleeder, filled the master with alcohol and sucked through several times then filled with DOT 5 and sucked 2 or 3 masters full through then finished up bleeding the system. Did the same thing on a car that had DOT3 in it only all I did then was pulled 5 through until it came out purple at each bleeder, didnt flush the system otherwise. Drove that 4500 lb car another 10 years with no brake issues!