62 brake bleed

[John F.]

I plan to replace the three rubber flexible lines and replace all four wheel cylinders, and then run denatured alcohol thru the lines and blow out with air. Should you run alcohol thru the master cylinder as well? I don't plan on replacing the steel lines. Is one quart of alcohol enough? (to run thru the system). Any help is appreciated!

[Mike M.]

Re: 62 brake bleed

yes, i'd fill the master cylinder with the solvent of choice, then pump the brakes to dispense the solvent in the master cylinder into a container adjacent to the master cylinder.mike

[Duke W.]

Re: 62 brake bleed

I recommend you disassemble the MC and clean everything with denatured alcohol, then dry everything and reassemble with brake fluid. If you can still buy a rebuild kit... I assume you are going to use DOT 3 or 4. Any trace of the alcohol should be removed everywhere in the system before you refill and bleed.

You can siphon alcohol through the brake pipes and blow them dry. How much? I don't know, but I'd buy a gallon. Denatured alcohol is a handy solvent to have around. It dissolves latex paint and many adhesives.

Duke

[John F.]

Re: 62 brake bleed

I plan on using DOT 5 since everyone on this site recommends it.

[Duke W.]

Re: 62 brake bleed

New wheel cylinders are assembled with conventional fluid, so you should disassemble them, clean everything with denatured alcohol and reassemble them with silicone fluid. Same with the MC.

Also flush the new hoses out since the ends are usually swaged on using brake fluid as a lubricant.

Your chance of a successful conversion with no problems downstream greatly increases if you start with everything squeaky clean and dry. You should endeavor to remove every last molecule of conventional fluid and dentured alcohol cleaning solvent before you add the silicone fluid.

The additional steps above are not that much more work, and they can make a difference in the long run.

Understand that DOT 3/4 fluid and denatured alcohol are not miscible/compatible with DOT 5 silicone fluid and can cause adverse reactions in the system.

Duke

[John F.]

Re: 62 brake bleed

I wasn't planning on rebuilding the MC. Can I just flush it with the alcohol? As well as all the lines, blow air thru, then install new wheel cylinders, and bleed.

[Duke W.]

Re: 62 brake bleed

Unless you're in the habit of flushing the brake system every couple of years, there is likely a healthy amount of sludge, dirt, and debris in the system, notwithstanding the residual gylcol fluid, which is NOT compatible with DOT 5, but it's your car...

My recommendation for the MC is in a previous post. You can ask as many times as you want, but my answer doesn't change.

Short answer: START WITH EVERYTHING CLEAN, DRY AND WITHOUT ONE REMAINING MOLECULE OF GLYCOL FLUID, THEN ASSEMBLE ALL HYDRAULIC COMPONENTS WITH DOT 5 AND GO FROM THERE.

Duke