Sunday, July 8, 2012

Bleeding the Brakes...and my insanity.

So it is Sunday.  I spent all of the morning and into the early part of this afternoon at work.  All I could daydream about was coming home and doing a little bit of relaxing in the garage while I attempt to "bleed" the brake lines of air bubbles.  Well, long story short, it was nothing at all like relaxation, unless one finds relaxation in the intense humidity of a South Carolina summer and swimming in Dot 5 silicone brake fluid.  Here is how I blundered my way through it.


Act I

I thought I would be clever and do a "solo" job on bleeding the brakes.  I read a technique published by "Gindi" on on how to do this without the use of any special tools.  Please note that this only works when installing new fluid throughout the lines.  One should never reuse used brake fluid.

I went to Lowes and bought a 6' long piece of clear tubing from the plumbing section.  I think it had an inner diameter of 1/4".  I actually brought in one of my spare brake lines to test it.  You connect one end of the tube onto the bleeder screw furthest from the master cylinder.  In my case, it was the rear passenger wheel.  Open up the bleeder screw and set the opposite end of the tube back into the master cylinder reservoir.  Slowly pump the brakes and watch the fluid slide through.  Keep an eye on the cylinder reservior making sure it never goes dry.  Watch for air bubbles in the tube coming out of the bleeder screw.  Once the air bubbles no longer come out and you see nothing but brake fluid in the tube, tighten the bleeder screw and proceed to the next furtherst bleeder screw.  All the while, the new brake fluid continues to empty back into the master cylinder reservoir. 

Easy peasy, especially with the tub off of the chassis.  I had a clear view of all four bleeder screws.

The set-up:  one end of the tube connected to the open bleeder screw
(in between the "s" tube to the inside of the tire)
and the other end of the tube in the master cylinder reservoir.

A close-up shot of tube on the bleeder screw.  At this point, it is clear brake fluid without any air bubbles.
Thank you to Gindi for the advice on how to do this by myself and poo-poo to the old man at Lowes that said I was a fool for trying it.  Well, I may be a fool, but it is because of other things.  Remember, this "trick" should only be done when installing all new brake fluid.  DO NOT DO IT WITH OLD, USED FLUID.  Over time, brake fluid likes to collect water molecules, so the brake system needs to be flushed every few years or so.  I went with the Dot 5 silicone because it supposedly resists the water molecules longer (so longer time between flushing) and it seems to be gentler on painted parts if it spills.

OK, so according to this blog, everything went smoothly.  Well, ha-ha, the joke is on me.  It did not go according to my plan.  Here is where I went wrong and hopefully the next dumb joker that attempts this (which will be me, I am sure) will read these notes and avoid this one major pitfall:



Act II

I would have bet (if I were a betting man) hefty sums of money that I had already confirmed and re-confirmed the tightening of all of the tube connections.  Evidently, I hadn't because as I was slowly pumping my brakes, I saw puddle after puddle after puddle expanding on my garage floor!  I was furious.  (ask my wife when she popped out to ask a question!)  Everywhere I looked there was dripping brake fluid.  I seriously thought that I had made sure that I had tightened the brake lines some time ago.  Even before I began to pour the fluid into the reservoir I thought to myself that I should re-check the connections.  I talked myself out of it because I was that confident that I had already done it.  Sabatoage maybe?

So, for an hour or so I crawled around in the puddles of fluid with my slippery wrenches trying to tighten all of the connections.  The worse one was at the base of the master cylinder, itself.  I had to remove the heat shield AND the steering column to adequately get to that one!

Knock on wood, I think it is done leaking.  I have kitty litter spread across the floor soaking it up right now.

Now, this isn't the end all be all of all definitive tests, but the brake pedal offered a pretty stiff resistance when pressed and I couldn't roll the jeep manually.  Now that doesn't say anything for the stopping power of a moving jeep at 45 MPH, but it does say something that if it is broken down and somebody is pushing me, I can stop it from rolling away!

1 comment:

  1. I think that calls for a celebration! I think it is not a bad idea to try bleeding and changing your brake fluids on your own. A little DIY would not hurt your vehicle, and reading your post, I think you did a pretty good job despite the leaks. But a help of a professional mechanic would not hurt either. You can probably ask some suggestions on the procedure of bleeding and changing brake fluids.