454Big

If you change from DOT 3 to DOT 5, what I will do next spring, how can you be sure that all the DOT 3 fluid is out of your system?

Can the brake system be flushed with any "helper fluid" to prevent moisture build up or do I have to dismantle all the parts and clean them seperately?

How the hell to clean the lines????
I already have stainless steel lines from VB/P and stainless calipers, but I have no idea currently how to remove the old fluid forever......

Please help with your ideas and knowledge!
Thanks!

Monty

Flush it out with Denatured Alcohol. It will help remove the the old DOT 3 fluid as well as any moisture.

mrvette

I juust take the lines loose at the calipers and master cylinder.... and blow them out with air....done job.... rebuild the master cylinder, and blow it out, I use water to wash it out, then blow dry, then bake in oven at 250F for about an hour....cool slowly, reassemble....
same cleanout for stainless calipers.....
now if this has all been recently rebuilt in good condition, you may be lazy and just open up all bleeders, remove lines from master cylinder, and blow system out, remove lines from calipers and drain/blow in reverse to get all fluids out.....work fluid out of master cylinder completely, blow it all out, then go ahead and refill as normally when system is reassembled....

IF you are going to rebuild calipers, use Vette Brakes/products O ring pistons kit, toss the springs behind them, and you are set....

GENE

lyonsh

I'd use denatured alcohol, and THEN blow them dry.

But why do you want to change to DOT5 (silicone) in the first place? If you bleed your brakes every couple of years like you're supposed to, DOT3 is just fine. OTOH, the myth about never having to bleed with DOT5 is just that - a myth. Even with DOT5 your system WILL get moisture in it (assuming you actually drive your car), and you'll need to bleed every 2 years anyway. Further, the moisture won't mix with the DOT5, but will "coagulate" in high spots, leading to rusting if left in there. And you have to be very careful filling up/bleeding with DOT5 because it tends to cavitate, which can make for mushy brake pedals.

In sum, DOT5 is an expensive PITA that doesn't solve the problem you're putting it in there for. Just my 2 x 10^-8 megabucks, of course. :cheers:

PatG

There is a distribution block/switch attached to the frame right off of the master cylinder. I have never had this off of my car to inspect it. Is there valving in this block? Should the lines from the block be removed and cleaned individually or can you blow air both directions through it?

PatG


[Modified by PatG, 1:59 PM 12/16/2001]

69bblock3x2

As others have stated use denatured alcohol to flush out the old fluid. I would caution you about blowing out the lines with air unless your compresser is set up with an air dryer / water separator. Compressed air is loaded with moisture.

John

454Big

OK, I got a first insight.

Any other recommendations?

(I have to mention that the car is purposed for being a show car only, not a daily or even permanent driver. I covered about 150 miles with this one the last 3 years...... :bb shame.....)

LT1driver

Stay with Dot 3 or 4

454Big

Why stay with DOT 3 or 4 ???

I still am not finished in my decision - have all three DOT´s here around....

mrvette

Dot5, is only slightly more soft on the pedal feel...and well worth that small sacrifice for no rust/sludge in the brake system.....dot3-4 are hydroscopic as hell, they absorb moisture, and right through the hoses, m/cyl cover, or caliper seals....there is NO downside to DOT5 fluid....period....
OH on a good rebuild, use the O ring pistons from Vette Brakes or some such...and toss the piston springs in the trash....

GENE

shoptek

Mrvette,
What is the advantage of tossing the springs out when rebuilding the calipers?

I did my fronts with the o-ring kit, and used the springs, but I'll be doing the rears soon.

Just curious----want to do it right.

mrvette

shop, on that spring toss, I guess upon looking at the poopieuation you compare it to other systems what do not use springs behind caliper pistons at all, and they are even more 'sensitive--cheaply built'....than ours....and since we are the only type brake/car system I know of that uses springs....I just decided they were not necessary....all they do is give a bit more pedal for the distance the pads may have to move to ensure contact with an out of lateral spec rotor....now it's not a cure for a rotor with an 1/8 th inch of warp....but it's fine with normal wear patterns...and not so sensitive as the -8 mil spec for our sharks....

leaving the springs out works well with either type piston/seal...but is more recommended for the Vette Brakes type O ring pistons...NONE stock...
I"ve run both types with dot5 and had no troubles....and no moisture collection either...

GENE