Brake Fluid for new system

[1983Pinin]

Hello,

I have an 83 Spider and plan to redo the entire brake system, other than the rigid lines--new braided hose, booster, master cylinder, rebuilds on all calipers, vacuum line.
Should I consider a higher DOT brake fluid for this new system? I plan to leave the rear brake compensation valve in the system.

Thanks for any tips.

--Peter

[Odoyle]

Nothing but DOT 3 non-synthetic. NAPA sells some. Will most likely want to replace compensator valve with brand new one, will also want new bushings for linkage rod on the diff. Be careful removing brake fittings, their made of a soft alloy which can easily be stripped. PB Blaster and wire brush any visible threads is a must (in my book). 10mm flare nut wrench is handy, some vendors also use a vice grip-style nut wrench which works well.

[rridge]

All brake fluid is synthetic. The choice is between glycol and silicone bases. Each has pluses and minuses. SAE 3 glycol-based is cheap and works well if the system is bled periodically to remove moisture saturated fluid.

[Odoyle]

Obviously DOT 3 is a man made substance, but you have to make sure it is not petroleum based, which would classify it as synthetic. DOT 5 is silicon based, which can never be mixed with anything.

[maxdog]

DOT 3 And DOT 4 are both "synthetic ", and petroleum based .They are synthesised from Ethylene Glycol which in turn is made from Ethylene ; itself a petroleum derivative .DOT 4 is a glycol based fluid with a higher temperature range than DOT 3
DOT 5 is a silicone based fluid which is totally incompatible with any Glycol based fluid and many of the commonly used rubber parts of systems designed for DOT 5. NEVER use DOT 5 in a system which has seen DOT 3 or 4.
Maxdog

[maxdog]

OOPS Major mistype in my previous post
Should have said " never use DOT 5 in a system designed for DOT 3 or 4""
Maxdog