AX Brake Fluid: Choices and Recommendations...

[CitroJim]

Today I find Daffodil's brake fluid is looking very manky and needs to be changed. It's dark brown and looks more like well-worn LHM rather than standard brake fluid

Being an LHM man at heart I'm finding the whole (new to me) subject of brake fluid types a bit confusing and muddled..

Should I use DOT3, DOT4 or go for DOT5?

I understand DOT5 is a silicone based fluid and will not mix with the other DOTs although there is variety of DOT5 that will

I believe DOT5 cannot be used with ABS systems but that's not an issue because Daffodil does not have ABS

Question is, for a lightly used car should I go for DOT5 with the advantage of it being non-hygroscopic and if so, how do I flush all the old fluid out before filling with DOT5 to ensure there will be no adverse reactions?

Or should I stick to using DOT4 or even look for DOT3?

Grateful your thoughts Thanks!

[white exec]

Be careful about actual silicone brake fluid, Jim, as its lubricating qualities are very limited.
The stuff was enthusiastically marketed a good while ago (by Namrick, Brighton, alongside their stainless steel nuts and bolts), as the ideal solution for classic cars. Unfortunately, many owners had to remove it when some types of master, slave and servo cylinders started to judder and creak.

I think DOT4 is what you should use, but check. The AX mechanic's booklet will have the spec.

[Paul-R]

IIRC Dot 5.1 is the next progression in DOT non-silicone fluids. Having said that, DOT 4 is probably sufficient.

[xantia_v6]

Stick with DOT4. But keep it off of your hands and paintwork, it is not nearly as user-friendly as LHM.

[white exec]

Thanks, Paul. That got me reading up on the DOT categories (Wikipedia, Brake Fluid).

[CitroJim]

Thanks all DOT4 it will be