Hi,

I have a doubt and I would like to know the answer. I would like to know if any DOT 5 brake fluid is good for the brakes of a Harley. My question is: is different the DOT 5 that is used in the cars and the DOT 5 that is used in bikes? Can I use any kind of this break fluid in my bike.

Thanks a lot for your inputs.

 

Any DOT 5 brake fluid is the same DOT 5 brake fluid. For cars and for bikes, it is the same brake fluid. If your Harley came with DOT 5 brake fluid then you should continue to use DOT 5 brake fluid in it.

 

Be aware that there is also DOT 5.1, so check very closely that you have DOT 5 for your Harley. These may have similar names, but they do not mix! Someone in the DOT should be drummed out for naming these two.

 

I always though dot5 was silicone. Have to check

Silicone is great almost no issues, except for one thing. It will absorb air. and shouldn't mix it with dot 3-4

If there is much change in temp overnight or altitude like in the mountains the atmospheer pressure changes and will allow air to go into and out of the brake system.

Racers don't have this problem cause they change out the fluid every race.

down on the Gulf coast might have to bleed it now and then. Overpasses are the highest hills.

 

Thanks to all for your inputs. Now I know that I can but DOT 5 in any automotive shop and that I don't have to buy the 5.1.

Thanks a lot, love this forum

 

This Wikipedia entry describes the different fluids. Your comment is interesting Old Gunny. I know DOT5 doesn't absorb water and shouldn't be mixed with the others - I discovered that the hard way with my own bike!

Javieret, happy to help, from the UK via the USA!

 

DOT 5 does not absorb water...but water will gather in the system and stay there. DOT 5 is more compressible that 3 or 4 also. HD has shifted from 4 to 5 and back again in the hydraulic clutch units. If you completely flush the system, you can replace either with the other if desired.