Softail Models Standard, Custom, Night Train, Deuce, Springer, Heritage, Fatboy, Deluxe, Rocker and Cross Bones.
Sponsored by:
Sponsored by:

Dot 4 and Dot 5 Brake Fluid??

Thread Tools
 
Search this Thread
 
Old Sep 8, 2008 | 10:57 PM
  #11  
07FXSTC's Avatar
07FXSTC
Tourer
Joined: Jan 2007
Posts: 351
Likes: 0
Default

From memory, my 2004 FXSTS used DOT 5. My 2007 FXSTC uses DOT 4. I guess Harley switched back. (????) I had to thank the guy at the parts counter because I was about to buy DOT 5 for the 07 when he told me it uses DOT 4. I asked why they switched "back" and he shrugged his shoulders.

By the way, I did accidently mix in the front master cylinder and then simply flushed a feew times with the DOT 4 and now use DOT 4. No rebuild required, BUT I only had itr in there for a few minutes when I realized my mistake.
 
Reply
Old Sep 9, 2008 | 12:00 AM
  #12  
philgrocks's Avatar
philgrocks
Cruiser
Joined: Apr 2007
Posts: 232
Likes: 1
From:
Default

I like the test... Best way to be sure... Take a couple of drops of the existing fluid into a cap full of the dot 5 or dot 4... If they blend you are good to go. If they separate, then keep looking.
 
Reply
Old Sep 9, 2008 | 08:45 AM
  #13  
KOBRAA2's Avatar
KOBRAA2
4th Gear
Joined: Apr 2008
Posts: 8
Likes: 0
Default DOT 4 Or DOT 5

I have an 04 Deuce that I bought a Harley multifit chrome Mastercylinder and noticed the top of new Mastercylinder says to use DOT4 and My bike took the DOT 5. I spoke with the servive dept and they had told me to use the DOT 5 since my hoses and caliper were filled with DOT 5 and the mastercylinder was new. thats possibly how come the lid says DOT 4
 
Reply
Old Sep 9, 2008 | 09:01 AM
  #14  
tlb's Avatar
tlb
Elite HDF Member
Joined: Apr 2007
Posts: 4,984
Likes: 8
Default flush or mix

I said flush the system not mix the two fluids together and ride for awhile to see if it gels. If you just wish to change from one type of fluid to another, all you need to do is flush completely. I do agree if the two are mixed and you would have more problems. Mixing is not draining, a little bit of DOT 4 left in the system, and then flushing out the little bit left over. Mixing would be having a low master cylinder and filling it with the wrong type.

Originally Posted by crazybastid83
Don't need to rebuild anything? Have you ever seen a brake system when dot 4 and 5 is mixed?
 
Reply
Old Sep 9, 2008 | 09:44 AM
  #15  
oldgeezer's Avatar
oldgeezer
Grand HDF Member
Joined: Dec 2004
Posts: 4,513
Likes: 4
From: Midland, TX
Default

2006 was supposed to be the DOT 4 changeover year for Softails.
 
Reply
Old Sep 9, 2008 | 01:00 PM
  #16  
ptibowie's Avatar
ptibowie
Advanced
Joined: Jun 2008
Posts: 68
Likes: 1
From: sgdfvs
Default

My guess is that someone replaced the resevoir cover. Since parts most times cover multiple years of bikes it probably just had the wrong thing written on the cover for your bike. It could be right for another bike that it fits.
 
Reply
Old Sep 9, 2008 | 08:32 PM
  #17  
Chaos's Avatar
Chaos
Tourer
Joined: Aug 2008
Posts: 373
Likes: 0
From: N. Kentucky
Default

Originally Posted by crazybastid83
If you switch to dot 5 from dot 4, you have to rebuild your master cylinder and calipers as well as replace brake lines. Dot 4 and Dot 5 do not mix, your o rings will turn to jelly causing brake failure.
Ya I can second that for sure. And third and forth. The powers that be at work (who obviously were never mechanics) got the bright idea to switch from 3 to 5 in our fleet in spite of our protests. OMG what a nightmare that caused for the next 2 years. I've never done so much brake work in my life. Well, somebody finally got a clue and the Dot 5 went away. Miracles of miracles, so did the brake work.
 
Reply
Old Sep 9, 2008 | 10:53 PM
  #18  
WARG's Avatar
WARG
Elite HDF Member
Joined: Jan 2006
Posts: 4,357
Likes: 11
From: The Lone Star State
Default

Mine takes DOT 4 and it's a 2006, but this may have been the first year of the change. I wish I had DOT 5, but don't really want to go through all the hassle of disassembling calipers, etc.
 
Reply
HD Forum Stories

The Best of Harley-Davidson for Lifelong Riders

story-0

7 Times Harley-Davidson Chucked Tradition Out the Window

 Verdad Gallardo
story-1

7 Surprising Harley-Davidson Products that Are Not Motorcycles

 Verdad Gallardo
story-2

8 Best Harley-Davidson Motorcycles Ever

 Pouria Savadkouei
story-3

10 Worst Harley-Davidson Motorcycles Ever

 Pouria Savadkouei
story-4

Killer Custom's Jail Break Is The Breakout That Refused to Blend In

 Verdad Gallardo
story-5

Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?

 Verdad Gallardo
story-6

Harley-Davidson Reveals Super Cool Cafe Racer Concept

 Verdad Gallardo
story-7

Engraved Rebellion: Inside Bundnerbike's Glam Rock II

 Verdad Gallardo
story-8

10 Motorcycles You Should Never Buy

 Joe Kucinski
story-9

10 Things Harley-Davidson Needs to Fix in 2026

 Verdad Gallardo
Old Sep 10, 2008 | 08:44 AM
  #19  
Chaos's Avatar
Chaos
Tourer
Joined: Aug 2008
Posts: 373
Likes: 0
From: N. Kentucky
Default

Originally Posted by WARG
Mine takes DOT 4 and it's a 2006, but this may have been the first year of the change. I wish I had DOT 5, but don't really want to go through all the hassle of disassembling calipers, etc.
Just my opinion, but I wouldn't do it. Yeah, you can, but it is difficult at best to get ALL of the residue from the old fluid out even when you rebuild everything and if you don't, it turns into a kind of nasty lumpy goo over time, kind of the consistency of spoiled milk chunks. (Im thinking of 3 to 5, not 4 to 5- I assume that would do something smilar) Not sure what the advantage would be. I guess the idea behind Dot 5 is not drawing moisture from the air? Dunno.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
ThrusterK
Touring Models
17
Aug 10, 2019 05:36 PM
fxdx1985
Dyna Glide Models
12
Feb 24, 2017 11:02 AM
K&L cycles
General Harley Davidson Chat
6
Mar 14, 2014 10:12 AM
Weed's Ironscoot
General Harley Davidson Chat
20
May 6, 2010 12:06 PM
Taterdog
Touring Models
32
Mar 29, 2010 06:00 AM




All times are GMT -5. The time now is 01:45 PM.

story-0
7 Times Harley-Davidson Chucked Tradition Out the Window

Slideshow: Harley-Davidson built its reputation on nostalgia, but every so often, the company took a hard left turn into the future.

By Verdad Gallardo | 2026-05-20 11:18:19


VIEW MORE
story-1
7 Surprising Harley-Davidson Products that Are Not Motorcycles

Slideshow: The bar-and-shield logo shows up on far more than motorcycles, some of the company's most unexpected products have nothing to do with riding.

By Verdad Gallardo | 2026-04-29 16:50:35


VIEW MORE
story-2
8 Best Harley-Davidson Motorcycles Ever

Slideshow: Not every Harley gets it right, but these are the ones that genuinely earned their reputation.

By Pouria Savadkouei | 2026-04-15 14:23:21


VIEW MORE
story-3
10 Worst Harley-Davidson Motorcycles Ever

Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.

By Pouria Savadkouei | 2026-04-01 20:01:09


VIEW MORE
story-4
Killer Custom's Jail Break Is The Breakout That Refused to Blend In

Slideshow: Killer Custom's "Jail Breaker" build focuses more on stance and visual aggression than mechanical overhaul.

By Verdad Gallardo | 2026-03-18 19:20:32


VIEW MORE
story-5
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?

Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.

By Verdad Gallardo | 2026-03-07 16:15:30


VIEW MORE
story-6
Harley-Davidson Reveals Super Cool Cafe Racer Concept

Slideshow: Harley-Davidson's new RMCR concept revives the café racer formula with modern hardware-and it may be exactly the reset the company needs.

By Verdad Gallardo | 2026-03-04 12:23:37


VIEW MORE
story-7
Engraved Rebellion: Inside Bundnerbike's Glam Rock II

Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.

By Verdad Gallardo | 2026-02-24 18:19:44


VIEW MORE
story-8
10 Motorcycles You Should Never Buy

Slideshow: There is no shortage of great motorcycles to buy, but we would avoid these ten.

By Joe Kucinski | 2026-02-19 14:50:51


VIEW MORE
story-9
10 Things Harley-Davidson Needs to Fix in 2026

Slideshow: Harley-Davidson's challenges aren't abstract; they show up in dropping shipments, shrinking dealer traffic, and strategic decisions that aren't yet translating into growth.

By Verdad Gallardo | 2026-01-13 18:33:17


VIEW MORE