Brake Fluid........sorry to ask
Road Warrior
Joined: Jun 2016
Posts: 1,751
Likes: 263
From: Catalina AZ
A buddy has a Buell, it is marked incorrectly....
He was having all sorts of brake problems after changing fluids (if I remember correctly it had to do with Brembo rubber parts) .
Did some research and found out it was marked wrong.
Flushed and replaced all the rubber parts of the system and the brakes work great now.
Last edited by GRWHD; Jul 21, 2016 at 07:39 AM.
Seasoned HDF Member
Joined: Aug 2011
Posts: 11,814
Likes: 5,120
From: SW Ohio
A 2004 should be DOT 5 silicone fluid, I don't think there's anything special about a Custom that would cause it to be using anything else.
Here's how to tell if what you have is silicone (DOT 5) or glycol (DOT 3,4,5.1):
Take a drop of the brake fluid and drop it into a cup of water. If it mixes and disapears, it's glycol. If it does not mix, it's silicone.
Here's how to tell if what you have is silicone (DOT 5) or glycol (DOT 3,4,5.1):
Take a drop of the brake fluid and drop it into a cup of water. If it mixes and disapears, it's glycol. If it does not mix, it's silicone.
OP this ^ is the answer to your question. It'll take 2 minutes to figure out and it'll take 2 hours to rebuild the master cylinder and caliper(s) if you introduce silicone fluid into a glycol system or vice versa. As far as flushing lines and going from one to the other? Not me, without a complete rebuild of everything including lines. A frozen caliper because of the eventual goo isn't on my list of things I'd like to do.
Last edited by Campy Roadie; Jul 21, 2016 at 07:46 AM.
Road Captain
Joined: Jul 2010
Posts: 527
Likes: 25
When i bought my bike used, it only had 8000 miles on it. But when they were adding some chrome pieces to it, they added a chrome front master cylinder cover and bought the wrong one as far as which fluid it used. I wouldn't imagine that someone had the wrong stock one on the op's back, but stranger things have happened.
Head
Head
Grand HDF Member
Joined: Dec 2007
Posts: 4,999
Likes: 55
From: Bay Area
I flipped an 04RKC a couple years ago and it came with dot 5. I disagree where someone said dot 5 will turn a straw color, thats dot 4. Dot 4 looks more like a vegetable oil or has a yellowish tint. Dot 5 is a purpleish color when new, and turns black when dirty. Ive done a conversion before on a bike but I used an engraver and made a 4 over the 5 after replacing everything when I did the conversion. Person didnt want to buy a new cap.
Sounds like your rear is original and the front has been compromised. Youre between a rock and a hard place, knowing it is wrong and now you have to do it right.
Sounds like your rear is original and the front has been compromised. Youre between a rock and a hard place, knowing it is wrong and now you have to do it right.
HDF Community Team
Joined: Nov 2012
Posts: 6,190
Likes: 2,419
From: USA
The OP's 04 RK should have come stock with DOT 5 silicone brake fluid, afaik.
Seasoned HDF Member
Joined: Aug 2011
Posts: 11,814
Likes: 5,120
From: SW Ohio
All Dot 3/4 brake fluids are synthetic. The important difference we're talking about here is glycol based and silicone based. A completely different thing.
Last edited by Campy Roadie; Jul 21, 2016 at 08:38 AM.
Tourer
Joined: Mar 2015
Posts: 288
Likes: 25
From: Tumwater, Wa
My bike is an '04 Road King. I just looked at an old receipt from the last brake job performed at the dealer, (10 yrs. ago). Part # 99953-A Dot 4 brake fluid. That's all I've ever used.
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HDF Community Team
Joined: Nov 2012
Posts: 6,190
Likes: 2,419
From: USA
It'll work. That said, take a look at your service manual or your owners manual. You'll see DOT 5 is what is specified. Part number 99902-77.
Seasoned HDF Member
Joined: Nov 2009
Posts: 15,705
Likes: 22,718
From: Farmington ,MS
The "purplish" color doesn't last for long...not a good way to determine what is in your bike.