big block ken

I noticed that the brake fluid is low in my '66, but I can't tell if it's standard fluid or silicone. Besides tossing it on my paint to find out the hard way, is there another way to test it? In the 80's I used silicone fluid and it was purple, but I'm not sure what's used now. Sadly, my brother recently passed away, and was the original owner of this beauty. So I don't know if he converted it when the calipers were replaced.

SonnyAK

Sorry to hear about your brother...I'm sure he'd be super happy you're taking care of the car now...

I had the same issue when I purchased my '66 and wasn't sure what was in the system. Dot 5 is silicon based and won't mix with water so take an eye dropper and remove a bit from the reservoir and then add a little water to it and shake it up...If they mix, then it's a glycol based and if not (stays seperated and beads up), then it'll be the Dot 5...

Hope this helps...Good luck with the car. I hope having it brings you great memories of your brother.

65-StingRay

I just bled my brakes yesterday and I use silicon fluid - It's purple.

65-StingRay

big block ken

Thanks Sonny. I'll try that. Joe rides with me always.

ohiovet

Silicone brake fluid is purple.
But, it can lose it's color over time.

SonnyAK

I am sure he does!! Enjoy every minute of it!

Wayne1964

If it hasn't been changed for some time bleed the whole system. I use dot 3 no problems and cheap. I change it every 3 years. Good luck.

big block ken

I mixed about an ounce of the mysterious brake fluid in a bottle of water and after shaking, it mixed in thoroughly together. No separation. So I guess I have the regular fluid. I also put some on a painted piece of metal and I'll see what it does to it over the next couple of days.

big block ken

That's a good idea, for piece of mind.

JohnZ

That test should be done with EQUAL amounts of brake fluid and water.

big block ken

Ohhhhhh. Okay. Here is a 1/2 of each mixed. Sat for about 10 minutes. Does it look like Dot 3 or 4?

65GGvert

Yes it does.

ref772

The best thing to clean up a spill of regular DOT3 brake fluid is water. The water soakes it right up. If you spill it on paint, flush it off quickly with lots of water. If its silicone fluid, you will just make a mess with water. Also, with regular fluid, you can put a little in your hand and it will get hot - absorbing the moisture out of your skin. That's why you should never use old fluid or leave the cop of the can open.

desertpilgrim

You prescribed the correct test in your question - get an eyedropper,
take a sample and put two drops on something that's painted - if it doesn't eat it, it's silicone or something other than regular brake fluid.