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Mixed Brake Fluid
Extreme HDF Member
Joined: Apr 2006
Posts: 10,449
Likes: 46
From: Roswell, GA
+1 on why would you do anything with DOT 4 fluid since HD didn't start using that until model year 2005 or 2006 and your bike is a 2000?
Get a Mighty Vac and flush the system with DOT 5 a couple of times to have fresh DOT 5 in the system.
Get a Mighty Vac and flush the system with DOT 5 a couple of times to have fresh DOT 5 in the system.
Stellar HDF Member
Joined: Dec 2009
Posts: 2,560
Likes: 279
From: North Cental Iowa
What he said. They didn't start using Dot 4 until 08, your bike came with Dot 5 & it is very unlikely that it has ever been changed over to Dot 4. If you want to be safe suck out what's in the master cylinder & then you can open a bleeder on a caliper just to get a little fluid out, put the fluid on some paint that you don't care about, anything doesn't have to be from the bike, Dot 4 will ruin paint. If it doesn't do anything to the painted part you've got Dot 5 in the system, that's the reason HD used Dot 5 in the first place, so if you spilled some it wouldn't ruin a paint job, it also deters rust in the system since it doesn't absorb moisture. They switched to Dot 4 when they went to ABS because the Dot 5 doesn't work as well. Bottom line is there's a 98% chance that you've got Dot 5 in your 2000.
Outstanding HDF Member
Joined: Dec 2009
Posts: 2,502
Likes: 6
From: Lapeer , Mich
if you have'nt DO NOT PUMP the brakes at all get the fluid out wipe it out with a rag if you did not get any inside you might be ok , fill it back up with dot 5 and maybe even drain that back out before pumping then fill again you may or may not be ok , how long has the dot 4 been in there, if you do it this way just be carefull if you have any problems they will show up soon , if you pumped it and mixed the two you might have to go through the system [ok yea reread the original post and yea you shoud be just fine if you put dot 5 in it cause that is what should have been it ] just forget this answer , I never woke up this morning
Last edited by 1st 96 ultra; Mar 28, 2010 at 03:01 PM.
Outstanding HDF Member
Joined: Feb 2009
Posts: 2,005
Likes: 53
From: ID Ho
Manual says to use DOT 5, and I wasn't paying attention to what I had in the master cylinder -- it is amber in color, which I assume is DOT 4. Poured about an ounce of DOT 5 in the master cylinder before realizing what I was doing. 
What now? Will bleeding very well and refilling with DOT 4 be okay?
What now? Will bleeding very well and refilling with DOT 4 be okay?
The official word is you cannot mix them or use one in a system that has had the other in it. Just flushing is NOT sufficient, you need to replace all rubber components.
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Stellar HDF Member
Joined: Dec 2009
Posts: 2,560
Likes: 279
From: North Cental Iowa
He didn't add Dot 4, he thought he had Dot 4 in it already, it shouldn't have since it's a 2000 model. He added Dot 5 which should be fine unless someone else had previously changed the system over before.
Outstanding HDF Member
Joined: Feb 2009
Posts: 2,005
Likes: 53
From: ID Ho
They didnt "go back to DOT4" in 07. DOT 3 was used prior to 1977 when they started using DOT 5, they never used DOT 4 until ABS was introduced in 05, and it was switched because DOT 5 will airate when cycled as fast as the ABS pump runs. The complete changeover was to eliminate the possibility of DOT 5 getting installed into ABS bikes at the factory.