Re-doing my drum brake system. What is the best choice for brake fluid nowadays?

[Big Bad Dad]

Yes, I did a search, but most of the brake fluid threads are old. I'm going thru the brakes on my 67 R/T. I just took everything apart, and while there is less than 10K miles on it since I did the brakes before, it has also been over 25 years. There has been some condensation in wheel cylinders. I plan to replace all wheel cylinders and rubber hoses. The master cylinder was replaced about 12 years ago, so I have not decided on it yet. May pull it apart and take a look. Anyway, what do you guys think is the best brake fluid to use now? My cars mostly sit a lot, but I am hoping to drive them more now that I am retired and have time.
I have always used DOT 3, but wonder if one of the newer fluids would work better for me as far as not having moisture problems.
Thanks
edit: This is the original 11" manual drum brakes.

 

[zyzzyx]

If not racing the car, do the work and put in 100% Silicone fluid. No more moisture and gummy junk
in the wheel cylinders. Silicone doesn't have an affinity for moisture.

 

[dadsbee]

Flush everything out totally and put in Dot 5 and never worried about your paint again...

 

[HALIFAXHOPS]

Hey if it had dot 3 in it and and I mean any of the rubber had dot there in it don't go dot 5 Not comparable at all. It will swell the crap out of the rubber. Seriously. @mobileparts Ask me how I know and the insurance company

Hate to say this google it

 

[71RRHI]

I just got done rebuilding front and rear brakes on my 67 500. I used DOT 5 silicone from Napa. Works great, but is a little pricey.

 

[zyzzyx]

I put Silicone in all of my motorcycles and never had a problem. Clean, clean, clean!

 

[dadsbee]

Says he's going to replace the wheel cylinders and rubber hoses Ray... As long as he flushes the master and lines not an issue.

 

[HALIFAXHOPS]

Seriously anything organic rubber. Still imbeded in ther. I thought it was BS also. Found out not in a good way

 

[snakeoil24]

Halifax your right on about this

 

[Big Bad Dad]

Seriously anything organic rubber. Still imbeded in ther. I thought it was BS also. Found out not in a good way

Even if flushing? What about rebuilding the cylinders with a kit to replace the rubbers? I wonder if rebuild kits are still sold for master cylinders? Hmmm... Rock Auto?

 

[Aron Gleason]

Hey if it had dot 3 in it and and I mean any of the rubber had dot there in it don't go dot 5 Not comparable at all. It will swell the crap out of the rubber. Seriously. @mobileparts Ask me how I know and the insurance company

Hate to say this google it

I've been told Dot 5 isn't good for older cars. I use Dot 4, and leave Dot 5 for the newer cars.

 

[Geoff 2]

If you are going to keep the car for many years, have your existing wheel cyls & M/c either brass or s/steel lined. No more rust problems.

 

[Kern Dog]

I've been told Dot 5 isn't good for older cars. I use Dot 4.

I've read your dodgy advice on other topics.
Dot 5 it is.

 

[YY1]

9 years with DOT 5 in my 73 after replacing the MC, calipers, hoses, wheel cylinders, and brake-kleening and blowing out the rear lines.

Slightly more pedal travel but that could be because I also switched power boosters and didn't mess with the actuator rod.

...and my MC is still black, like I painted it 9 years ago.

 

[HALIFAXHOPS]

9 years with DOT 5 in my 73 after replacing the MC, calipers, hoses, wheel cylinders, and brake-kleening and blowing out the rear lines.

Slightly more pedal travel but that could be because I also switched power boosters and didn't mess with the actuator rod.

...and my MC is still black, like I painted it 9 years ago.

So all new rubber then?

 

[YY1]

So all new rubber then?

\I can't remember if I changed out the hose between the rear line and the axle, but likely did.

 

[HALIFAXHOPS]

Makes sense. One thing good on dot 5 is it does not eat the paint. I went 4 wheel disk on my dart using jeep rear brakes. Changed all the lines, rebuilt the front calipers. Definately has its positives.

 

[Canadian1968]

Question about this topic. What is it that reacts ? Is it something in the dot 3 that reacts with silicone in the dot5

 

[zyzzyx]

Dot 3 or 4. Does'nt play well. Silicone is more or less inert.

 

[dadsbee]

Only "example" I have. This is a brake reservoir cover that was running DOT3 for 40 years and someone thought a quick top up with power steering fluid wouldn't hurt anything... maybe something the "enlargement" folks want to look into!