Hi guys, Noticed today my brake fluid needs topped up, is it ok to mix brands as long as its all Dot 3 ?? I ask this as I dont know what kind is already in it.

yes that is fine - but as you have low fluid check your pad wear (I assume no leaks)

 

also if it hasnt been changed in a couple of years I would recommend a refresh with new fluid (I myself would go with Dot 5.1 as it has higher temp tolerance than 3)

Good point about the pads, I will check them first, is it ok to change to dot 5.1 with regards to the internals of the system??

Should be fine I have 5.1 in mine and never had a problem. 

Don't even think you can get dot 3 anymore.

4 is a direct replacement, check with subaru if your unsure i think that 5 has a different chemical compsoition and could rot the lines and seals if not compatable.

5 is different that is silicone based which can affect the seals - 5.1 is different again but similar to 3 and 4 (just with higher temp tolerances) so shouldnt cause any damage to the rubber

Jay, thanks for that i assumed the two were the same as the mazda wouldn't accept either. I know what i'll be putting in mine at next change now :-)

This is the Shel stuff I use at the moment but OPIE have a wider choice of brands - which includes DOT 3 if needed

 

http://www.smithandallan.com/prodpage.aspx?id=3727

 

http://www.opieoils.co.uk/c-450-brake-fluid-clutch-fluid.aspx