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2015 Optima EX
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70 Posts
Discussion Starter · #1 ·
I just replaced the two front calipers on my Optima, and I have a hugely squishy pedal. I bled the two front lines, and when I do, the driver side comes out yellowish and flows smoothly, no air bubbles.

Let me go back a little bit. The reason why I am changing the calipers is that the passenger side front seized up and was causing an annoying sound, which is why I was changing them. Got a good deal on some Raybestos calipers so decided to change both fronts.

So when I did the caliper that was stuck, as soon as I removed the brake line off the back of the caliper, the piston shot out of the caliper and a ton of fluid leaked all over the **** place. Now I am trying to bleed the line, and at some points in the process, foamy, yellowish fluid comes out. At other times it doesn't look like anything is coming out. Then again at other times it looks like a clear fluid is coming out with air bubbles.

I had the wife inside the car, and would turn the bleeder valve a quarter turn, and have her press the pedal. I then closed the valve and had her release the pedal, then went through the process over again. I did it for quite some time and couldn't get any yellowish liquid out. The bottle I was using (connected to the bleeder valve with a vinyl line) was about 1/3 full when I started, and now its about 3/4 full. Some of that came from the driver side.

I am at a loss, if I should continue to bleed that side or try something else. I am open to suggestions. All the parts came off and installed easily, that was a huge plus. If only they worked. I don't want to have it towed to a shop if at all possible.
 

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2011 Kia Optima
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4,511 Posts
Need to bleed all the calipers in sequence:
RR
LF
LR
RF
You can have someone pump then open/close bleeder, or can use a hose attached to the bleeder running into discarded brake fluid, and just push pedal down repeatedly, but don't run out of fluid in the reservoir. Naturally close bleeder before removing hose.

Unusual that the piston would come out when hose removed, actually have never see/heard of that before. If the piston was loose in the bore, make certain you check the brake hose as at times they become compromised as the internal structure breaks down and after using the brakes, the breakage won't let the fluid return to the master cylinder, the pads stay against the rotor and acts like a stuck caliper.
 

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2015 Optima EX
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70 Posts
Discussion Starter · #3 ·
Hi Turbonut! Thanks for the reply. Let me give a little more history. I had a squeeky front passenger wheel. Basically it came down to the rotor was so rusted on the edges that the metal mounting piece that holds the pads in place was rubbing on this rust at a certain point as the wheel rotated. Well, as I had the caliper open to access the area where the squeek was coming from, the kid started up the car and kept his foot on the brake after it was started, and well, it fully extended the caliper cylinder. I could not for the life of me get it to retract, so I decided to replace the calipers and rotors while I had it apart. Mind you this car only has 40k miles on it. I did both sides by the way.

Driver side was no issues at all, a tiny bit of fluid came out during the quick change of the caliper, but not much. The passenger side was another story. Like I said, as soon as I released the brake line screw from the caliper, it shot the cylinder out and blew out a ton of fluid. The cylinder launched hard enough that it rolled across the entire driveway.

The reservoir did not seem to empty out though. I kept bleeding and filling, bleeding and filling until I finally gave up. A coworker of mine has a Mityvac, not sure if thats spelled right, that he is going to let me borrow. I will go ahead and bleed all the lines as you suggested. I guess it could have gotten air back into the system with that loss of fluid. The fluid that came out of driver side was yellowish, which I guess is normal. I don't see anything floating in it or anything.

I won't be able to get to it until saturday late afternoon. I will let you know then.
 

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2011 Kia Optima
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4,511 Posts
Mighty Mac is a pain and time consuming, I use a vacuum pump, but many years ago used the hose trick as I could do the job myself, as long as the end of the hose is in the fluid so as no air comes back up the hose as the brake pedal is released. Works great and easy w/o having someone pump the brakes and/or opening/closing the bleeder each time. Nice to have someone depress the pedal while you watch the fluid to see if any bubbles are coming out of the hose, naturally must use a clear container.

Can't get my arms around the piston being blown out when the line is removed!!! One would believe that when the line is removed, the pressure would be released?? I've blown the slider pins out as when they were broken off/stuck inside the bracket, I'd use heat and the air expanded to a point the slider came out like a bullet.

When I rebuilt calipers, I'd use air to push out the piston(s), but will place a piece of wood inside the caliper to keep the piston from going out like a missile.

Good luck and need anything just yell.
 

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2015 Optima EX
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70 Posts
Discussion Starter · #6 ·
Well, finally got it going. The problem was that the Cylinder was empty, but not sure how. I didnt realize how fine the mesh basket filter in the cylinder was. I would fill it up to the lip, then attempt to bleed the brakes, not realizing that it was still draining into the master cylinder. When I finally shined a bright ass light in there, I was able to see that it was empty. Filled it up, and worked like a champ. Stupid of me.
 

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2011 Kia Optima
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4,511 Posts
Well, finally got it going. The problem was that the Cylinder was empty, but not sure how. I didnt realize how fine the mesh basket filter in the cylinder was. I would fill it up to the lip, then attempt to bleed the brakes, not realizing that it was still draining into the master cylinder. When I finally shined a bright ass light in there, I was able to see that it was empty. Filled it up, and worked like a champ. Stupid of me.
At least you're man enough to admit what it was!
Enjoy the ride.
 
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