Brake fluid

[T.O.Craig]

Howdy again,
I can't find anything in the instructions of what type brake fluid to use. I have dot 4 Motul high temp fluid that I use on motorcycles.What do you think?

 

[BobTurner]

Do not use automotive brake fluid - too corrosive. Use Mil-spec hydraulic fluid. I don't have the numbers handy but there is the 'standard' one, and the recommended one with a higher flash point.

 

[DaleB]

Royco 782 is a good choice, I have a quart sitting in my garage which is probably about enough for two lifetimes. The more research you do the more options you'll find... some guys use ATF, I think. But MIL-PRF-5606H or MIL-PRF-83282 hydraulic fluids are the safe choices. Spruce has a good selection, as do other places.

The only universal no-no seems to be most automotive brake fluid.

 

[Auburntsts]

+1 for Royco 782

 

[F1Boss]

Mobil 1 ATF (available anywhere)

I use this stuff. The specs on the container suggest it complies with MIL-PRF-83282...

http://www.qclubricants.com/royco/royco_782.htm

https://mobiloil.com/en/automatic-transmission-fluid/synthetic-atf

You can buy it locally (anywhere) with no hazmat charges. I really like this aspect.

I'm gonna GUESS Dot 5 brake fluid might work (silicon based - the seals will thank you). I have heard that high altitude exposure allows the air in the Dot 5 to expand...but I have not had that experience (I use it in my motorcycle clutch system; had it to 10500MSL with no issues).

Carry on!
Mark

 

[RV3bpilot]

Royco 782 is the stuff to use.. I did some research on the best and safest brake fluid to use in aircraft and this is the stuff.. Can be found at http://www.skygeek.com/

 

[rapid_ascent]

I'm not sure about aircraft grade brake fluid but I know that Auto grade brake fluid is hydroscopic (absorbs water) so you can't keep open containers for use later. Water in the fluid will boil and cause braking problems. Others that are more knowledgeable in this area can comment.

 

[gyoung]

Royco 782 is the stuff to use.. I did some research on the best and safest brake fluid to use in aircraft and this is the stuff.. Can be found at http://www.skygeek.com/

+1 MIL...83282 is the stuff to use. Aeroshell markets it as Fluid 31. It can be mixed with 5606 which is what you'll find at most GA repair shops.

 

[jjconstant]

I know it seems passe to use the factory but:

http://vansaircraft.com/cgi-bin/store.cgi?ident=1460966615-132-612&browse=am&product=b-fluid

and when you look it up here

http://www.qclubricants.com/royco/royco_782.htm

it conforms to mil 83282

 

[T.O.Craig]

Love this "Brain Trust". Thanks to all for your help....