I believe the original spec for brake fluid is DOT 3. DOT 4 is 100% compatible and has a higher boiling point. (So I use DOT 4.) DOT 5 is silicone based and it is advised you not mix it with DOT 3 or DOT 4. If in doubt, extract some brake fluid from the reservoir. Mix that with some DOT 3 or DOT 4 in a clear container. It should be obvious if they mix or not.

Again, 'normal' coolant is fine. It is also advised one not mix types as they can form sludge or gel. Other than color I'm not sure how to differentiate the types... see: Understanding Different Types of Antifreeze

 

I believe the original spec for brake fluid is DOT 3. DOT 4 is 100% compatible and has a higher boiling point. (So I use DOT 4.) DOT 5 is silicone based and it is advised you not mix it with DOT 3 or DOT 4. If in doubt, extract some brake fluid from the reservoir. Mix that with some DOT 3 or DOT 4 in a clear container. It should be obvious if they mix or not.

Again, 'normal' coolant is fine. It is also advised one not mix types as they can form sludge or gel. Other than color I'm not sure how to differentiate the types... see: Understanding Different Types of Antifreeze

Thank you, I will use Dot 4. As matter of fact I saw on the Valvoline bottle written DOT 3/4 fluid.

 

..DOT4 is good enough for a 80ies Alfa Romeo , the older ones 60 /70 used ATE BLUE which was /still is DOT 3

What I observed is, that some cars that used to use DOT3. will show up damages in the rubber /seal area, when using DOT4 the seals look like ****ake mushrooms... DOT 4 is more agressive to the OLD rubber parts. But a 1984 Spider should already use the newer style rubber parts...

 

..DOT4 is good enough for a 80ies Alfa Romeo , the older ones 60 /70 used ATE BLUE which was /still is DOT 3

What I observed is, that some cars that used to use DOT3. will show up damages in the rubber /seal area, when using DOT4 the seals look like ****ake mushrooms... DOT 4 is more agressive to the OLD rubber parts. But a 1984 Spider should already use the newer style rubber parts...

Thank you. I will use DOT 4.

 

Changing fluid is fairly simple. If you don't have a pressure power bleeder it is a two person job. Use a syringe to suck out most of the fluid in the reservoir. Add new, fresh fluid then have your trusted assistant work the pedal as you go around and open the bleed screw (attach a rubber hose aimed into a container). You say, "pedal down", your assistant confirms, "pedal down" then you open the bleed screw. When fluid stops coming out close the bleeder and say, "pedal up" and your assistant confirms, "pedal up". Start with the brake furthest from the master cylinder and repeat until the fluid comes out clean. Usually the old fluid will be dark &/or cloudy so the change will be noticeable. Refill the reservoir and do the next furthest brake and so on. Never let the reservoir run empty or you'll have to start all over as that can allow air to get in the system. Tip: place a piece of wood (short length of 2X4 for example) under the brake pedal. This limits the pedal travel but keeps the master cylinder seals from travelling into uncharted territory. This prevent the seals from getting damaged. Not an issue with the clutch master cylinder as the pedal there routinely goes full stroke. Don't forget to remove the piece of wood before driving the car...

 

Thank you. I was familiar with both ways of changing brake fluid, but i haven’t done it for the clutch cylinders. So it looks it is the same way.