I recently got some air in my rear brake line and after bleeding and changeing the fluid to dot 4 castrol it feels.....like it should be alittle tighter on the brake lever. thing is i changed the lever as i was doing it to the black billet harley one from the stock lever so dont really have anything to compaire to......I thought maybe theres a better brake fluid because im 99.9% sure theres no air in there now..... can you guys tell me what fluid you are running so i can get the right stuff?

 

Just got the Fat one services and Dot 4 is what the dealer used, flushed the lines right though so its all new fluid,Front and back, the pessure comes on a lot sooner both front and back, made a lot of noticable difference. ( Just noticed some riders on the forum have Dot 5, my dealer in Manchester used Dot 4, may be a model thing, I'd your the local dealer a call .

Ride safe

Reddog
Manchester UK

 

DOT 3 / DOT 4 are glycol based (can be mixed without a problem)
DOT 5 is Silicone based ( CAN NOT BE MIXED WITH DOT 3/4 )

if it came with DOT 5 the system MUST be flushed before using DOT 4, otherwise it will gel up the lines(you'll have to replace them).

 

HD's used to come with DOT5 from the factory, but now come with DOT4. I am not sure whether 5 is better than 4, but I do know not to mix them. Your XB will be DOT4, so you are good to go. Maybe ride for a while and do another bleed to purge any air remaining.

 

if you over fill the reservoir it will feel mushy

 

thats probably it then cause mines right to the top.......i think i will see now if theres any more air to bleed and take some fluid back out...... thanks for the tip

 

Dot 5 is not water soluble so it will last longer than DOT 3 or 4. My 2002 runs DOT 5 as does the wife's 2005.

 

I run DOT 5 out of habbit. It's what I used on all my dirt bikes. I just put new front lines on and used it. Until I have a reason to totally flush the rear I'll just stick with 4.

 

By 2006 all H-D's went to Dot 4. I used to like the Dot 5 silicone stuff only for the fact that it wouldn't damage paint and didn't draw moisture. Under a microscope (i've read) Dot 5 is full of tiny air bubbles. It's just part of it's make up-they never rise to the top. This accounts for the spongy feel when using dot 5. All new H-D's are Dot 4 and have a MUCH more solid feel, than the Dot 5 days. Reservoir level should be 1/4" from the top per the service manual (reservoir level has no effect on feel at the lever what so ever) it would have to be empty or completely full (not allowing for fluid relief port return and the pistons in the caliper would probably stick out)for this to happen. My 2cents-Glenn.

 

well mine did