brake flush

[Guest 38cadillacjack]

working on brakes on my 37 chevy and 38 lasalle .what should i flush with?thinking of changing to dot 5. thanks

[Owen_Dyneto]

I flushed with denatured (rendered undrinkable and thus not taxed) ethanol before converting to DOT5. I suppose isopropanol would work as well and is easier to find. Acetone would be another alternative though more of a fire hazard than the others. Nevertheless, take precautions regarding open sources of igntion or hot surfaces. I followed with a prolonged dry air blast to evaporate any remaining alcohol.

[Guest 38cadillacjack]

thank you sir ,the alcohol was what i was thinking,due to easy to get and cheap.the dot 5 was suggested by another old car guy ,so i thought it would be better as it don't absorb water. thanks again,guess i'll go work on them.jack

[buick man]

There are give and take issues regarding silicone brake fluid useage. It is easy to clean your system out to prepare for silicone but the reverse is not. Also, silicone brake fluid does not like the heat as in down hill runs on the brakes or heavy brake useage. If the car will be a garage or yard statue, then silicone will keep the corrosion issue down to a purr. However, if you just bleed your brakes once a year and use DOT 4 or Racing Blue then you will have no problems with the water or the rubber seals.

[Guest 38cadillacjack]

thanks buick man,guess i'll think about both good &bad,then put one in.these cars are all original drivers,so maybe dot 4 is the way to go. sure a lot cheaper too. thanks again, jack

[Guest martylum]

Jack--- I've used silicone fluid for years in 5-6 cars but only after replacing al the wheel cylindrs and master cylinder rubber parts. Some articles I've read on brakes in old cars do not recommend flushing and refilling a Dot 3 system with silicone.

I've had no problems with rubber cup swelling as some people have reported when refilling old rubber parts. My 30 Desoto has had the same silicone system since 1990 so it can last if done well.

Martin Lum