Hi guys, bit of advice please, while i was away with work recently my dad decided that my car could do with the brakes bleeding and topping up with brake fluid, great i thought until i realised he'd put dot 4 in it and not dot 3 and mixed them together. Is this going to be a major issue does anyone know? Ive searched google and there doesn't seem to be an issue as apparently there pretty compatible but just want to make sure theres not a specific suabaru problem? 

I have heard it can eat in to your rubber seals and hoses but not sure how true that is. Maybe just more scare mongering than truth but I would drain them all again and re do it if you are concerned. I do only use 5.1 myself though. But I would say you will be fine but doubt the life of it would last as long with it being old stuff mixed with new.

Yeah take the crap out and put 5.1 in

Dot 4 is a repalcment for dot 3 which isn't widely available these days, it's made up of the same stuff if I remember correctly,

It's dot5 and 5.1 you cant mix [emoji3]

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Thanks for the reply guys, I've drained it and filled completely with dot 4 just to be safe as it seems they only sell dot 4 where i am lol, can i put dot 5 or 5.1 in with stock brakes and brake lines? 

Yes mate my brakes are all stock about to get some braided hoses though soon :) 

Happy days, cheers mate just got a bit concerned because there's quite a harsh warning on my filler cap saying to use only dot 3 lol 

Never mix dot 5 with any of the others it's silicone based and destroy everything !

The others can be used together but it's advisable to drain completely if your using more than a little bit to top off.

Th others are glycol based if I remember hence why it strips paint.

The main difference between the different dot's is the dry and wet boiling points. Dot 5.1 being the higest and best for fast & heavy repetitive braking

Whats the best way to ensure system is completely drained first? 

Undo lines from the calipers ome at a time , pump pedal, obviously have a container to catch the fluid that comes out l. Then suck out anything thats left in the reservoir with a turkey baster or suction gun. When you refill the system and bleed the brakes it will clear the resg of the old stuff out

Cheers Stanton500 

All great advice above - cant stress enough dot 5.1 good  - dot 5 bad (seals swell calipers seize etc etc ) (unless you have a race car and have specific seals suited to dot 5)