Hey Guys (and gals) I am going to put new brake calipers on my 78. My question is this...how can I plug the master cylinder during this process to keep it from running dry on me? Plus any pointers on the caliper job will be appreciated. Thanks

 

I have had luck with golf tees. Now would be a good time to drain and flush your system of the old fluid. Over time the fluid absorbs a lot of moisture which can cause corrosion issues in the lines and the calipers too. You can drain one leg at a time starting at the longest run, just make sure you keep fresh fluid in the M/C and let it drain until it runs clear. If you don't keep the M/C full during the process, you may have to re-prime the M/C (commonly referred to as bench bleeding).

 

Thanks for the idea. I have been working on this brake issue for about a year or more...frustrating. I do not want to make it more frustrating with a dry master cylinder in the process.

 

Another way to do it, is just keep the Master Cylinder full. Then, after removing the wheel, simply clamp the rubber brake hose with a Vise grips to stop the fluid. You can simply cut the rubber hose below the Vise grips (good time to replace them). Next do the caliper replacement & hard line. Attach the rubber hose. Put a catch pan and newspaper underneath. Then, get ready to work quickly and remove the old hose and attach the new. Be very careful to not get any brake fluid on any paint. Bleed that brake. Recheck for leaks. Keep Master Cylinder full. Do the next one.

Enjoy!

 

You do not have to touch or plug any lines at the master cylinder. And you don't need anyone to help you bleed the entire system - And you don't need to use vice grips on the front rubber hoses or use golf tees! - Read on:

I just did mine and all you have to do is each Caliper - one at a time.

1. Simply remove the line from the caliper that you are replacing.

2. Plug the line with a small tight fitting vacuum plug cap (local auto parts sell them) - just slide it over the lines flanged end - (slide the nut away from the flanged end (rears) - its that simple. (no fluid will leak out and the mc remains full and all lines are still air free). System is not compromised. They will stay air tight - not one drip.! For the fronts just get larger vaccum plugs that will tightly for over the front steel fittings that thread into the caliper.

3. Replace the caliper

4. install the caliper line back to the new caliper. Secure line nut. For fronts just thread and tighten line back into caliper.

5. Get a Mityvac vacuum tool (All parts houses sell them)

6. Attach small diameter hose to the Mityvac and slip the other end over the Caliper Bleeder. (I prefer the speed bleeders myself - check em out (Russell amongst other sells em & Ecklers etc.....or local parts houses). Or just crack the stock one open....

7. Open the bleeder valve and start pumping the Mityvac until you see solid fluid coming out to the Mitvac bottle that catches the fluid. Check the Master Cylinder fluid levels as you proceed to make sure you don't drain the MC while bleeding the calipers.

8. Proceed to next caliper - This way your system NEVER loses any fluid or lets air in while you are doing the job.

I use DOT5 fluid - since 1982 - PERFECTO!!

FLAWLESS! Enjoy!

 

Thanks a lot for the great ideas. I replaced all the soft lines last week so hesitant to put the vice grip to them. I just hope I have great hard brakes when finished.

 

Thanks for the information. The Calipers are now ready to install. I am looking forward to the job when I can get the time to get to the Auto Hobby Shop on base and get to work.