Flushing/changing brake fluid

[njsteve]

Flushing is a wonderful thing. Your brakes will thanks you.

I usually use a hand-vacuum syphon and pull out 90% of the fluid from the master cylinder with the tube so it sucks up all the rusty gunk that has accumulated at the bottom of the reservoir. Don't pull all the fluid out otherwise you'll have to bleed the master cylinder again.

Then fill it with fresh stuff and go from there.

If you don't think you need to change brake fluid, look at this photo which is of the internal piston in my 73 after 40 years with the same brake fluid.

[Bill Pritchard]

I don't think you will find any one overwhelming consensus of opinion on this subject. If Mercedes recommended to flush brake fluid every year, I would say they were concerned as much about flushing cash from your wallet as fluid from your brake system [img]<<GRAEMLIN_URL>>/rolleyes.gif[/img]

I know the only time I have ever used silicone (DOT-5) brake fluid in a car is on the Hemi Challenger I restored back in the 1980's. The brake pedal always had a very different 'feel' to it in that car, as compared with a car with DOT-3 fluid. Over the years since, I have read about many other people who had similar results.

[SS427]

Dot 5 does in fact does have a different feel in the pedal and almost always feels a little mushy. It is also prone to 'seepage' due to the difference in viscosity. However, I feel the benefits of silicone not harming paint and not holding moisture far outweighs the cons and have used it on all my restored cars since the 80's with only one complaint.

[jasonL78]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SS427</div><div class="ubbcode-body">Dot 5 does in fact does have a different feel in the pedal and almost always feels a little mushy. It is also prone to 'seepage' due to the difference in viscosity. However, I feel the benefits of silicone not harming paint and not holding moisture far outweighs the cons and have used it on all my restored cars since the 80's with only one complaint. </div></div>

I second Dot 5. From what I am told Dot 5 can't be mixed with Dot 3 or 4. So the best time to change over would be when everything is new. You will never get all the fluid out of the calipers when trying to change over. The only thing I would say is a problem is Dot 5 consistancy is a lot thinner. Sometimes your fittings won't seal 100%. If any piting is in your flared fittings say caliper or master your will get some leakage. Again Dot 5 don't eat paint either. Pro's and cons for both.

Just my 2 cents....

[earntaz]

What is with the Chinese post???!@#$

[earntaz]

What is with the Chinese post???!@#$

Am I the only one that can see these two post??

[firstgenaddict]

Silicone is a smaller molecule.... thus will seep where others will not.
I have found that with double flare stainless lines I have had to &quot;burnish&quot; or &quot;lap&quot; the flares by inserting the fitting together and hand snugging the nut then spinning the line in the fitting, then snugging a little more and spinning again, then after tightening I have had no problems, this seems to seat the flare.

[BJCHEV396]

I've never had a problem flushing out DOT 3 brake fluid and replacing with silicone.Use gas line antifreeze for the flush and then fill with silicone.Has worked on a '66 Corvette,'68 Camaro and a '70 Nova.