Another Brake Fluid Question for the Experts

[Eric]

I'm going to be replacing my brakes w/ SSBC calipers and I'm replacing the aged rubber lines w/ the braided ones. I was thinking of switching to silicone fluid but was unsure of the best way to thoroughly flush the system. I'd like to get the old fluid out of the system before the new calipers and lines go on. Like most old ragtops this car gets 2k max miles a year.

1. Since I'm not replacing the master cylinder and the frame lines, is the switch a bad idea?
2. Should I flush the system w/ silicone before I take the old calipers off?
3. How do I know when it's flushed, knowing that it's probably impossible to fully flush?

 

[fastglass95]

Brake Fluid??

I to drive my 1980 only about 1,000 - 2,000 miles per year and decided to stay with normal brake fluid.
I have had very good results and see no need to switch to silicone (save it for implants!)

I do use Valvoline SynBlend DOT4 fluid, which is not silicone but just good quality normal fluid with a higher wet boiling point than DOT3 fluids

Just invest in a cheap "Mity-Vac" vacum pump and bleed your brakes every year or two, flush them when installing new calipers. To flush, I just vacum through about 2 quarts of fresh fluid till everything runs clean.

Bleeding brakes (or flushing) is not that bad of a job to do!

This is just my experience and opinion, but I don't see the need for silicone in my cars, too many things can go wrong when using it!

Let us know how the SSBC calipers work out.

 

[80convertible]

I agree you don't need silicone. It was designed for racing and not street use. As it is hydrophobic, it will not absorb water thus causing it to pool in certain spots and begin corrosion process. Using good Dot 4 fluid with regular brake fluid changes is best medicine and also cost less. a

Regards,

Jim

 

[DDLS3]

I got to agree with both of the previous posts. Silicone fluid is not the cure all it's billed to be. If there is any, even a trace of DOT 3 left when you re-fill with silicone your headed for trouble, it will cause the fluid to turn to jelly. Expert I ain't, but I listen well, and I've heard the stories. SS re-fitted calipers is a big step in the right direction.

 

[72 Bluz]

Stop it, you guys...

Just when I thought I had this "brake fluid concept" under control, 71Shark hits me in the head with his torque wrench. More to ponder, thanks 71.

Did find out that the previous owner upgraded Xena to stainless. I'm exporing brakes this weekend.

Feeble minds want to know...
72 Bluz

 

[Hib Halverson]

For anything other than show cars or cars that are stored for very long periods of time DO NOT use silicone brake fluid. At high tempertures it compresses slightly and degrades brake pedal feel.

For normal street use a great choice if Vavoline's synthetic brake fluid. It's a DOT4 fluid and works really well in high-performance street applications.

For all-out racing, I suggest Motul DOT5.1 or Motul 600.

To flush a C3, you want to flush the system before you bolt on the new calipers. Sacrifice a couple of pints of cheap DOT3 fluid and run them through the existing system until the fluid runs clear at each caliper bleeder.

Then, install the new calipers and brake hoses.

Finally, fill the master cylinder with the Vavoline or Motul and bleed until you get that fluid at each caliper bleeder.

Don't forget to bleed the master cylinder. Some have bleeders. The ones that don't require you to "crack" the fittings coming out of the cylinder to bleed.

Typically, C2/3 disc brake bleeding goes easier if you have the back of the car jacked up real high.

Generally, if you start with a dry system, the only way to get all the air out is a pressure bleed.

In the past I've always recommended people NOT use vacuum bleeding with C2/3 disc brakes because the OE piston seal design allows air to flow backwards past the seal. The new SSB calipers might allow that depending on the seal design SSB uses.

 

[Eric]

In the past I've always recommended people NOT use vacuum bleeding with C2/3 disc brakes because the OE piston seal design allows air to flow backwards past the seal. The new SSB calipers might allow that depending on the seal design SSB uses.

With that in mind, has anyone ever used the speed bleeders? I've seen them advertised in the catalogs as allowing fluid out but no air in.

 

[mytoy]

no problems

My 78 L 82 set around alot , I had problems with the brakes I put the silicone fluid in about three years ago haven;t had any problems since, I have been very satisfield with the results