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I've changed the brake pads on the front of my S80, 1999, and took it out for a test drive to make sure all is well, and the brake pedal still goes all the way to the floor! I checked the brake fluid reservoir and it appears to be full, what gives? Thanks guys!
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A simple question, but may be note worthy -- is there any fluid on your garage floor and how is the level in the reservoir?
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n0v8or,
It kind of feels like there is an iflated balloon between the pedal and the floor, I also pushed the caliper in with a C clamp as I've done many other times with other vehicles. I did not remove the caliper or the rotor and the old pads had a little over an eighth of an inch left. I thought I was being pretty preventative, but this has got me just a little concerned. It is my wifes car and I don't feel comfortable with her driving it now. A friend of mine says that the new pads need to be broken in and it will take about fifty miles for the chemicals and stuff they treat them with to break in, he doesn't think it's a problem, but just needs to be driven for a little while. Again, when I get in it for the first time and pump the brakes, they pump up real tight like usual and then I drive for a few miles and have to pump them up again so to speak! I truly appreciate ALL the advice here!
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posted by
someone claiming to be n0v8or
on
Sun May 22 05:46 CST 2005 [ RELATED]
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I have seen cases where pushing in the piston too quickly and/or without removing the reservoir cap damaged seals in either the master cylinder or ABS unit. The good news is that if you can hold a firm pedal for 30-60 seconds with constant firm pressure (after pump up), you probably don't have such a leak.
After more than 25 pad changes in my "career" to date, I have never touched the rotors on any vehicle, or had a case where the outer edge ridge or rotor grooves caused excess pedal travel to the extent you describe. I've replaced the front pads twice on my S80, and rear pads once.
Here is a test to see if your problem is caused by a air or the pads being positioned too far from the disc after being pushed back by the rotor:
(1) Engine at idle so power assist works.
(2) Obtain up a firm pedal and hold for 15 seconds.
(3) Release the pedal, turn off the engine, and go do something else for a half hour or so. Don't move the vehicle.
(4) Repeat step (1), then see if you have excess pedal travel again. If yes, you likely have a hydraulic problem (dealer or pro recommended).
If no pumping required for a firm pedal at step (4), here's the next test:
With car in neutral and hand brake applied, jack up each front wheel and rotate the tire 10 full turns or so by habd. This permits rotor runout to push back the pads. Now check pedal travel.
I've also seen cases where the "ears" of the new pads were binding in the guides due to burrs created by the stamping tool, causing one or more pads to be jammed at an angle. This reduces effective pad area in contact with the rotor. I always sand the burrs off the ears and grease the guides with hi-temp silicone grease. You can visually check for this.
I think I have some intructions somewhere for "brdding" new pads.
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I would like to thank each of you that were so kind to help me with my dilemma! This board is truly a place of refuge for many including myself. I have a friend that lives nearby that is an auto tech. He is difficult to get ahold of, but by chance I was able to get him to test drive my car after we both went to church today. He said it was the new pads that needed to be broken in and proceeded to perform the 8 step exercise that was mentioned here first to me. By the way, he had no knowledge of the advice I was getting here, I just wanted to see what his opinion was, and it matched up perfectly to the kind help I was getting on this board! He also gave me a gentle lecture on using aftermarket parts and told me that within a week the brakes should be working perfectly and that I in fact did a good job changing them. Once again, thanks to all who replied to my cry for help!
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posted by
someone claiming to be n0v8or
on
Sun May 22 05:48 CST 2005 [ RELATED]
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"bedding", not "brdding"
Here they are:
Bedding Metallic or Carbon/Metallic Pads - (NEVER DRAG the brakes)
Note: Never “Bed” pads on rotors which have not first been “Seasoned.” Always allow a substantial coast down zone when bedding pads that will allow you to safely drive the car to a stop in the event of fade.
1. Perform four repeated light to medium stops, from 65 to 10 mph, to bring the rotors to temperature.
2. Perform two heavy stops, back to back, at a point just pending wheel lock, from 65 mph to about 5 mph.
3. Drive for five to ten minutes to create cooling airflow, without using the brakes if at all possible.
4. Perform three light stops in succession.
5. Perform eight heavy stops, back to back, at a point just pending wheel lock, from 65 mph to about 5 mph.
6. Drive for ten minutes to create cooling airflow, without using the brakes if at all possible.
Metallic brake pads need high temperatures to keep the pad “Bedded”. If you drive the car for a period of time without using the brakes extensively, you may need to “Bed” the pads again. This is not a problem. Simply repeat the procedure.
When switching from Performance Friction Carbon Metallic pads to semi-metallic brake pads (something we do not recommend), you will need to wear through the layer of carbon that the PFC pads have deposited in the rotor surface. The new pads won’t grip well at all, until this layer of carbon is removed.
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You did not give us a lot to work with,IE new disk or not? This should be no more than the second set of shoes on the disk. After that you need a new disk. The ridges(inner and outer) on the old disk keeps the shoes from bedding in until the pads wear to the shape of the ridges. If the brakes pump up while stopped and the pedal gets firm, you're probably OK. I just did this job and I rode the brake while keeping the car going for no more than 15 seconds, followed by a long cool down period (longer than 5 minutes). My brakes are seating and pedal travel is close to normal now. You may get some groaning while the pads are wearing in.
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posted by
someone claiming to be n0v8or
on
Sat May 21 13:26 CST 2005 [ RELATED]
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"Still" implies that the pedal went to the floor before you replaced the pads. If so, a pad replacement won't solve the problem. Most likely, there is either air in the hydraulic system, or the master cylinder or ABS unit has an internal leak.
If this is a new problem you did not have before the pad replacement, did you open any caliper bleed screws during the process?
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n0v8or,
This wasn't a problem before, the brakes were fine, I just needed to replace the pads and I don't know what the deal is, no leaks, didn't open the bleeder. The pedal never went to the floor before, if I pump it a few times it will tighten up, but then after leaving it sit for a while, it will go to the floor again when I first hit the pedal? I'm stumped, anything to check out and how to do it will really help! Thanks in advance!
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posted by
someone claiming to be n0v8or
on
Sun May 22 01:57 CST 2005 [ RELATED]
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I see I took your earlier message too literally.
Try this test:
With the engine running, pump as necessary to obtain a firm pedal. Now hold that pressure on the pedal for about 60 seconds, and see if the pedal slowly moves toward the floor. If it does, there is an internal leak (assuming the reservoir chamber stays full). If not, there may be air in the system.
Some questions:
As you pump it, does the pedal feel like there ia an inflated baloon between it and your foot?
How did you retract the caliper piston to install the new pads?
Did you remove the caliper or rotor?
Approximately how much friction material was left on the old pads; more or less than 1/8"?
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More thoughts on your brake problem. First, the aforementioned ridges tend to move the pad away from the disk (particularly while driving) further than normal, cocking it a bit. This is normal and will require extra pedal travel to move the pads in until they conform to the disc. Unfortunatelly, the use of the parts of the master brake cylinder which normally don't get used can be bad news, particularly if the fluid had not been changed every two years as Volvo recommends. The moisture which brake fluid naturally collects can cause rust at the limits of pedal travel, and could be part of the problem. Let us know how the test suggested by NOv8or comes out.
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I just did the brakes on my S80 and had the same problem. I replaced the pads and rotors with genuine volvo parts and the pedal would go to the floor and would not build back up. Turns out I put the wire like spring that mounts on the outside of the caliper on backwards (the tabs were pushing on the wrong side of the caliper). I switched the spring around on both wheels and the brakes were good as new.
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