air in brake lines

[dgjks6]

So, my DIY woes continue, but today I actually fixed something. When I was at the dealer yesterday they noticed that the right front brake lines into the caliper were loose because there was brake fluid on the caliper. They said it had been going on a while because some of the paint on the caliper was starting to peel up. They tightened them for me and recommended a brake fluid change because the brake fluid was dirty. One of the few things that I am skilled at is brakes. The first time the dealer wanted $800 to do the rotors and pads on my 1998 grans prix I quickly learned how to do it myself. I don't usually change the entire fluid out except on my BMW as recommended because when I change the brakes and rotors I always remove some fluid from the reservoir and bleed the lines. I have never seen air in a brake line in my life. The way I do it is I attach a hose to the bleeder valve and use a family member to pump the brakes as I open and close it.

So fast forward to the 996. When I got it, it stopped well, but not as well as my BMW. When I got it the brake fluid was low and I topped it up wondering why it was low. After the trip to the dealer I figured out why it was low and did not worry. Today I changed the brake fluid. On the right side I saw an air bubble go through the hose during the bleeding process. It did not surprise me too much because if the line was loose on that side I figured air could get back in. But...when I did the left side I also saw an air bubble come through the tube.

After I was done I tested the brakes. It now stops as well as the BMW. It amazed me, one little air bubble in each side makes a difference. Now for the question. Where did the air come from. Is my theory right that if there is a leak on the right caliper a little air could get in? Can that air get from the right side to the left?

As an aside, did you know you can not lay the tires flat on the concrete to clean them or you will scratch them? I found this out the hard way. Next project, DIY wheel refinishing.

[JFP in PA]

So, my DIY woes continue, but today I actually fixed something. When I was at the dealer yesterday they noticed that the right front brake lines into the caliper were loose because there was brake fluid on the caliper. They said it had been going on a while because some of the paint on the caliper was starting to peel up. They tightened them for me and recommended a brake fluid change because the brake fluid was dirty. One of the few things that I am skilled at is brakes. The first time the dealer wanted $800 to do the rotors and pads on my 1998 grans prix I quickly learned how to do it myself. I don't usually change the entire fluid out except on my BMW as recommended because when I change the brakes and rotors I always remove some fluid from the reservoir and bleed the lines. I have never seen air in a brake line in my life. The way I do it is I attach a hose to the bleeder valve and use a family member to pump the brakes as I open and close it.

So fast forward to the 996. When I got it, it stopped well, but not as well as my BMW. When I got it the brake fluid was low and I topped it up wondering why it was low. After the trip to the dealer I figured out why it was low and did not worry. Today I changed the brake fluid. On the right side I saw an air bubble go through the hose during the bleeding process. It did not surprise me too much because if the line was loose on that side I figured air could get back in. But...when I did the left side I also saw an air bubble come through the tube.

After I was done I tested the brakes. It now stops as well as the BMW. It amazed me, one little air bubble in each side makes a difference. Now for the question. Where did the air come from. Is my theory right that if there is a leak on the right caliper a little air could get in? Can that air get from the right side to the left?

As an aside, did you know you can not lay the tires flat on the concrete to clean them or you will scratch them? I found this out the hard way. Next project, DIY wheel refinishing.

First of all, normal maintenance on your 996 is to do a compete brake and clutch hydraulic system flush with new fluid at least every two years, which entails replacing all the fluid. This is critical to get all the absorbed moisture out before it starts to corrode some of the expensive bits like your ABS and PSM valves and controls.

If you had a loose line or connection, I am not at all surprised you found a bit of air in the system. When you release the brake pedal, a loose fitting will pull air into the system. Over time, this can amount to quite a few large bubbles in the system.

And you are not the first to discover that the spokes on some of these wheels protrude out past the tires, we see it all the time.