Brake Fluid?

[papajoe]

Do I have to use silicone brake fluid in the 1979 Vette?
I wouldn't think so....

 

[crause]

The vette shop that rebuilt mine said that you need to use a high quality (name brand) DOT 3. He also said that the system should be flushed every three years. Has anybody else heard this?

Andy

 

[brusso]

I don't think that silicone brake fluid was around in 79, so I would think that the Corvette shop was right. You should flush out your brake fluid, I just don't know what is the periodicity.

 

[eants]

This brings up a question that I have, what is the best, most recommended way of changing the brake fluid in my vette? I have seen some devices that can be connected to each caliber and fluid is forced up into the master cylinder. The theory here is to force all air upwards and into the master cylinder. Has anyone used this pump-type tool? Where can I pick one up? Can it be rented?

Thanks in advance

 

[Culprit]

eants, it's a vaccum pump. Instead of forcing the new fluid in through the calipers, what you're doing is sucking all the old fluid out. As you do this, the fluid level in the master cylinder drops, and you keep refilling it with the new fluid until all the old fluid has been sucked out and the new fluid has filled the system.

Air in the system at the calipers is bad enough, but forcing air up into your master cylinder is even worse.

Semper Fidelis,
Culprit

 

[JohnZ]

This brings up a question that I have, what is the best, most recommended way of changing the brake fluid in my vette? I have seen some devices that can be connected to each caliber and fluid is forced up into the master cylinder. The theory here is to force all air upwards and into the master cylinder. Has anyone used this pump-type tool? Where can I pick one up? Can it be rented?

Thanks in advance

That's the "Phoenix Injector" tool - have never used one; I use this instead - takes all the grief out of C2/C3 brake bleeding:

www.motiveproducts.com

 

[KOPBET]

I would presume that you would still need to bleed the brakes, then drive the car and engage the ABS system to cycle new fluid into the ABS reservoir, and bleed again in order to get rid of ALL of the old fluid?

Is this still the case with this product?

Do I have to use silicone brake fluid in the 1979 Vette?
I wouldn't think so....

You cannot mix glycol based and silicone based fluids for obvious reasons therefore the entire sysem would have to be purged and dried before adding silicone based or DOT5 brake fluid.

In other words, no.

 

[Roy]

A Note About Dot 5 Brake Fluid

If you are running a stock Vette as a street vehicle, do not, I repeat do not use Dot 5 brake fluid. Dot 5 was designed for high temp race applications where the fluid is changed after each race. The "good news-bad news" about Dot 5 brake fluid is ironic if not redundant - it doesn't absord moisture and it doesn't absorb moisture.

Think about it. Dot 3 and 4 brake fluids are hydroscopic and absorb moisture, that's why an annual brake fluid change is recommended. Is the hydroscopic action a bad thing? No, brake fluid was designed to absorb and suspend moisture to prevent the moisture from collecting and destroying critical brake parts. Besides, changing the brake fluid is a required maintenance item that is easily performed.

Dot 5 brake fluid on the other hand will not absorb much moisture so the fluid itself retains it's integrity and operating performance. The bad news is that the brake lines, calipers and fluid still heat up and cool down, causing condensation to form in the brake lines and calipers. Where does this moisture go if it is not absorbed into the brake fluid ... to the lowest point in your brake system - your calipers. While the Dot 5 fluid will retain it's integrity, the water that pockets in your calipers will cause corrosion, pitting of the caliper and piston and will boil when hot.

So if you plan to use Dot 5 brake fluid and you have replaced all master cylinder and caliper seals as well as rubber brake hoses with silicone compatible parts and you are willing to change the fluid about once a month instead of once a year (does Dot 5 fluid really cost $5 a pint?) just to operate your Vette in non-race conditions, then Dot 5 may be the perfect choice.

 

[papajoe]

Brake Fluid

Thanks for the good info