National Desoto Club

What is the current thinking on flushing a braking system on a 59 and then using DOT 5 (silicone) brake fluid instead of DOT 3?

I am replacing lines, hoses, master cylinder and wheel cylinders so the flush is actually a "new" empty system.

_________________
Life is good on Bremer Pond.
59 Firesweep Sportsman

I'm about to do the exact same thing. I've never converted over after flushing......always started with all new parts including new lines. This will be the first time after doing a flush although all wheel cylinders and master will be new. I'm going to first flush with alcohol and then with the silicone brake fluid. After that will go to the new cylinders.

You'll be fine since everything will be new on your system.

_________________
1956 Fireflite 4 door Sedan
1957 Fireflite Convertible

Thanks for the reply. Working on brakes is tough duty in my book so I want to get it right the first time.

_________________
Life is good on Bremer Pond.
59 Firesweep Sportsman

In 1987 I purchased my 39 Desoto and then after approx. 3 months the dot 3 brake fluid and mater cylinder went tot he floor. I replaced with Dot 5 Silicone and have used ever since and have had this In the car for 31 years.

Rich Hartung
Desoto1939@aol.com

Not current but still relevant: http://www.desoto.org/phpbbforum/viewto ... one#p19929

Mark

Gents,

I've had generally good results from silicone fluid too- it has been in my 1952 Firedome for 35 years. The car was in storage for almost 30 years. When I took it out, the brakes had a lack of pedal reserve- that is, the pedal went almost to the floor. I've been chasing this problem for the last year or so. I finally found the root cause. At the bottom of both cups in the master cylinder was a rusty nasty goo.

Apparently, water had condensed in the master cylinder reservoir, run to the bottom where it rusted the bore of the master cylinder. While Glycol-based brake fluids will hold water in suspension relatively harmless for some period, silicone rejects it. It beads and settles to the bottom where it is almost impossible to bleed out, as the bleeds are designed for air. Here is a photo of the bore in my 52 Firedome power brake master cylinder. Gee, I hope this is limited to the master cylinder....

_________________
Brent Jacobsen
Owner of a 1952 Desoto Firedome