I went to pick up a load of fluids yesterday including a couple of litres of 5.1 brake fluid. The guy serving me turns around and tells me it's for race use only, not for road vehicles?! I asked why and he did the rabbit in headlights look. I asked if he was confusing it with Dot 5, the silicon based fluid, he glazed over and told me it's just not for road use. He's completely wrong right, I understood it to be compatible with any Dot 3/4 system and has the bonus of a higher boiling temperature?

 

My brake systems been dismantled in full around the engine bay. If I'm going to replace the fluid with Dot 5.1 what's the best way of flushing the old stuff in the lines out as it's been sitting around for ages exposed to the atmosphere especially the rear lines for example that haven't been removed? Just suck up the cost and do it with 5.1 or run a litre of Dot 4 through first?

exactly as you said...

http://www.epicbleedsolutions.com/resources/faq/difference-between-dot4-and-dot51-brake-fluid/

 

and I guess.. you might as well use the dot 4 to clean it...

I used dot 5.1 on mine just pre mot and had issues with my brakes.

 

Not likely related to the 5.1 but I flushed it all through and then used dot 4 and mine a great now after the caliper rebuild.

I use 5.1 and was told the same. I checked it out and the bottle had EUV approved and that's what matters.

exactly as you said...

http://www.epicbleedsolutions.com/resources/faq/difference-between-dot4-and-dot51-brake-fluid/

 

and I guess.. you might as well use the dot 4 to clean it...

 

Seconded.......

 

..... But I just keep to the DOT4 as I'm easily confused....:wink:

I've been told before it is more sensitive to taking in moisture, so may have a shorter life. Perhaps that's a down side, if it's true.

 

I reckon you're fine.