hi guys
i want to change my brake fluid from the old to silicone fluid.
i have a new master cylinder and rear wheel cylinders.
i have power front disc brakes on my 69 camaro.
i am going to purge/clean out the brake system as good as i can, but....
1]how well do i have to clean out the old fluid from the system? will the two fluids react with each other?
2]is the assembly fluid used in the new master when it was put together from the factory need to be cleaned out before adding the silicone fluid?
3]what about the porportioning valve?[the block thing under the master]does that have to be taken off and flushed/blown out?
4]also the front brake calipers.....taken apart and flushed/blown out?

what is the best way to do this job?
thanks guys

------------------
69 Camaro RS/SS 350.
GM 2.02 angle plug heads.
223 dur/480 lift hyd cam.
69 z/28 alum high rise.
69 z/28 780 vac sec holly carb.
4 bolt mains,steel crank,forged flat top pistons.
Turbo 350 2800 stall with shift kit.
3:73 12 bolt posi.
functional cowl induction & ZL2 hood

You'll find almost everyone telling you NOT to use silicone brake fluid....unless the car will be stored in a museum.

A better idea is a high quality DOT 4 synthetic like Valvoline Syntec.

Les at Lone Star Brake and Clutch in Austin, the top brake shop in town, recommends against silicon fluid and in their warranty paperwork it says "the use of silicon brake fluid voids all warranties".

I asked them about this and they claim that silicon damages rubber parts in the brake system which causes malfunctions and leaks.

Give them a call at 512-385-4262 if you have further questions.

I went through three complete sets of stainless calipers on my Corvette. I would drive only a few miles and the pedal would soften up. Bleed the brakes and everything would be OK for a couple of days then it would soften up again. Changed all four calipers twice more and same problem. Flushed the system with DOT3 and no problems in several years. Also I kept seeing a red film show up on to of the fluid in the master cylinder. This too stopped with DOT3. I think it was dissolved rubber from the caliper's piston seals.

does the dot 4 valvoline syntec synthetic eat the paint??

if so ,how do you get around the paint eating issue?

DOT 4 fluid doesn't eat paint. It's all I use.

Jody

do you have to flush the system good if you use dot 4 or is it compatible with the old stuff? is the old stuff dot 3?

this silicone fluid i have is dot 5.
i thought silicone was a rubber persevative???
i heard that there was problems with some of the original old silicone fluid.
any more thoughts you guys????
how about you david pozzi?

[This message has been edited by z/27 camaro (edited 04-12-2002).]

I would not use Silicone fluid. I'm not saying it absolutely won't work. But the pedal may be spongy, your brakes may not work right when used hard, like when you are going really fast and are REALLY depending on the brakes to save your butt.

I have had two friends use it, and one wrecked his 69 Z/28 JL8 due to brake failure, the other was a Porsche 911, he had NO CONFIDENCE in his brakes after putting it in. His local Mechanic "expert" said it was the best, so they tried it. The pedal was spongy, not firm like before.

I finally made my Porsche friend call Tilton Engineering and the guy there convinced him to put Castrol LMA in it (he wasn't believing me) and there was no more problem.

As to the paint problem, just be careful with the brake fluid. I think Synthetic is great, but will damage the paint too.
Having an accident due to brake loss can REALLY damage the paint! http://www.belray.com/consumer/Q&A%20pages/q&abf.html
David

------------------
Check my web page for First Gen Camaro suspension info:
David's Motorsports page (http://ourworld.compuserve.com/homepages/David_Pozzi/)
First Gen Suspension Page (http://ourworld.compuserve.com/homepages/David_Pozzi/first_gen_suspension.htm)
67 RS 327 original owner. 69 Camaro Vintage Racer, 65 Lola T-70 Chev SB Can-Am Vintage Racer

[This message has been edited by davidpozzi (edited 04-12-2002).]

DOT 3 and DOT 4 are 100% compatible. And both eat paint eventually (if left on...just be careful not to wash the car with the stuff).

Its just that DOT 4 has a higher boiling point so will remain more effective longer than DOT 3.

Stick with DOT4 (I use Castrol LMA in all my cars); just bleed/flush it every two years. Silicone fluid is more trouble than it's worth, unless you're going to let your car sit for ten years.

------------------
JohnZ
CRG
'69 Z28 Fathom Green