free website stats program brake light not working | Harley Davidson Forums

brake light not working

kennyw

kennyw

Active Member
hi just changed rear pads on my 2005 1200c sportyand now the brake light does not work,works off front brake lever ? ant help would be gratefully received
ken.w
 
thanks for quick replies guys,no i did not bleed brakes ? but i may have to,manuel states dot5 fluid which is purple,but i came to change front pads & the fluid is amber coloured dot 5.1 perhaps.yet clymer manuel says donot use 5.1,so can i just flush out old with dot 5 ?
 
KennyW...OUCH!!! IF you put the wrong fluid in that master cylinder. Should have put in DOT5 Purple colored Silicone based fluid (worn out fluid turns to clear amber color and can fool you). If you read the top cover or the owner/service manuals you would have known this...sorry.

DO NOT use DOT 4 or DOT 5.1 which is Amber colored Etylene Glycol based! Get a turkey baster and get as much of the fluid out of there as you can...wipe it clean with microfiber cloth (don't want lint in there), put in DOT 5 and then bleed the contaminated fluid out of there pronto. I learned about DOT5.1 on this website...

DOT rating only has to do with the boiling temp...nothing to do with the actual fluid content...Silicone was used in racing circles for many years because of it's higher boiling temp, and "inert" qualities and was the highest temp stuff you could buy. DOT5.1 was introduced with little fanfare and kinda fooled most into thinking higher boiling temp meant higher performance but failed to read the fine print that it was EG based or compatiblility issue with unique Silicone based DOT 5.

Ethylene glycol is a brake fluid intended to swell seals slightly, while Silicone is inert so seals can be made to a tighter tolerance. That is why you can end up with "sticking" or "locking" brakes...and silicone fluid has a tendency to settle out, so the good news is if you flush it out quick enough the EG based fluid will get out of there when you bleed, IF the seals have not been damaged already...

As for the brake light switch, it is likely a symptom rather than a root cause...the swelled seals may be sticking already in the master cylinder and slow to retract...you may be in for a master cylinder & caliper rebuild as well, as the sticking may only get worse from the contaminated fluid.
 
Last edited:
The DOT 5 doesn't stay purple, it turns amber after a while. DON"T mix the dot fluids, use only what is made for the system and what is in there now.

DOT Brake Fluids - Harley Davidson Community

Your problem sounds like the rear brake switch. You can jump the wires in the plug at the switch to verify this. The light should light if all else is OK.
 
thanks glider,i have put dot 5 but the fluid in already was amber coloured,so hopefully i can just bleed until all is purple again,then when i went to do front ,opened up & it was amber so i left it,i will go down to dealers sun & get more dot 5 & replace the front as well,thanks for all your help,just hope i have't a rebuild to do ,sun is out and the roads are calling
 
I wouldn't push the fluid you put into the system through the system but rather suck it out of the master cylinder and replace it with the proper fluid. When you mix fluids it turns into something like small pellets and will ruin the system if you don't get 100% of it out of the system. This is why you shouldn't push it through the system but remove it the way it went in and then purge the system thoroughly with the proper fluid.
 
thanks for all your help again guys,completly bleed out the old fluid,seems to have done the trick,brake light switch on order from jersey £18.59,the other is a bit intermitant,plus it looks a bit worse for ware,must have been from the salt & a few shower we have had ,
ride safe
 
You must log in or register to reply here.
Back
Top