jl2 Posted January 15, 2006 Report Share Posted January 15, 2006 I changed the front brakes on my 03 S80 (new rotors, EBC green stuff pads). Brake action is good, but pedal travel now seems excessive compared to before brake change (I also bled the front brakes - no air whatsoever, pedal is not spongy, just long). I changed the brakes last year and do not remember any change in pedal travel. Any suggestions or ideas? Thanks. Link to comment Share on other sites More sharing options...
howardc64 Posted January 15, 2006 Report Share Posted January 15, 2006 I changed the front brakes on my 03 S80 (new rotors, EBC green stuff pads). Brake action is good, but pedal travel now seems excessive compared to before brake change (I also bled the front brakes - no air whatsoever, pedal is not spongy, just long). I changed the brakes last year and do not remember any change in pedal travel. Any suggestions or ideas? Thanks.I just had the same exact experience. After bleeding 4x (with no air bubbled coming out each time) I've come to believe it is the rotor's surface protectant. I used brakleen on the rotor surface prior to installation and was careful not to get grease on there. After brakleen, the rotor surface still had this coating on it that looks like clearcoat with circular grains from manufacturing.After 3 weeks, the brake pedal travel is much less and brakes grab really well. The rotor surface rust much faster now than when I first installed them. So I'm guessing it just took some time to burn off whatever that was on there.I read somewhere that sanding the rotor surface to provide a none directional grain is a good idea after the oil film is cleaned off. Can anyone confirm? I might try that next time. Link to comment Share on other sites More sharing options...
GTM2U Posted January 15, 2006 Report Share Posted January 15, 2006 I changed the front brakes on my 03 S80 (new rotors, EBC green stuff pads). Brake action is good, but pedal travel now seems excessive compared to before brake change (I also bled the front brakes - no air whatsoever, pedal is not spongy, just long). I changed the brakes last year and do not remember any change in pedal travel. Any suggestions or ideas? Thanks. Right off the top this is usually caused by not bleeding the system enough or properly. Depending on what you did do when you changed the pads may have caused a porportioning valve to bottom out and get stuck. I don't know your awareness skills so have to ask if you are getting brakes to all wheels or if you are getting any warning lights? You didn't indicate how long ago or miles driven since replacing the pads. It's possible the pads are hanging up in the caliper and you are applying pressure evenly to one pad but the other is not. I'ts also possible the caliper centering mechanism is binding and again applying pressure to only one pad. Either of these will cause excess pedal as the piston or caliper springs back from the uneven pressure. Did you open the bleeder when you prepared to put the new pads in, did you allow the resivoir to become empty when bleeding. How much grunge is in the resivoir and did you bleed to clear fluid. Do not use rapid pedal strokes when pumping for pressure or bleeding for this makes a lot of tiny bubbles which are hard to bleed out. You haven't given us enough to be more specific so you need to start with the bleeding using a hose dipped in a collector bottle so air can't suck back into the system and do all the wheels. This may take 3 complete passes to ensure the system is free of air. Let us know what you find and if nothing solves it for there could be more problems which could include the master cylr hanging up. Cheers, GTM2U Link to comment Share on other sites More sharing options...
GTM2U Posted January 16, 2006 Report Share Posted January 16, 2006 I just had the same exact experience. After bleeding 4x (with no air bubbled coming out each time) I've come to believe it is the rotor's surface protectant. I used brakleen on the rotor surface prior to installation and was careful not to get grease on there. After brakleen, the rotor surface still had this coating on it that looks like clearcoat with circular grains from manufacturing.After 3 weeks, the brake pedal travel is much less and brakes grab really well. The rotor surface rust much faster now than when I first installed them. So I'm guessing it just took some time to burn off whatever that was on there.I read somewhere that sanding the rotor surface to provide a none directional grain is a good idea after the oil film is cleaned off. Can anyone confirm? I might try that next time. Hmmm, some people can't even wash dishes properly... :-) You should have removed all of the coating from the rotors expecially if a dark anti-rust was used. This requies soaking in solvent and brushing, then rinsing with clean solvent before using Brake Kleen. If they came in a special treated paper then flooding with the cleaner and using a clean shop towel wipe it off and use a new towel for each rotor before mounting. You can't have fingerprints on the surface so again spray and wipe with clean towel. So it sounds like you got off to a bad start and there is no "next time" for it's now or you may have already spoiled a good set of rotors by making hot spots because of the coating. I always keep a spare used brake pad around for a sanding block to take the glaze off new or used rotors. 36 to 80 grit automotive sand paper is good for this, the outside of the rotor is easy but the inside will be a PIA to get a decent cross hatch with the shield in place. Still you have to domething so all you can do is work from the caliper and rough it up. If you have a 3" sanding disk for a drill or die grinder they will make short work of the deglazing cross hatch process. You will rotate the rotor while doing this so you don't get stuck in any one place. Since you have the pads out again and depending on what you find it can be simple or complicated. With badly contimanated pads you may have soak them in solvent and then use a torch or gas burner to heat unlil there is no more smoke. Might even have to do this 2-3 times to get all the crap off/out of the pad. You will need a full sheet of 80 grit paper and a flat surfact so you can then put the pad on the paper and sand them clean. Thirty second to a minute each pad should be enough but there is no substitute for this process, if you still have contamination you will have to do the soaking and heating process again before sanding. That's about the only way to get back to where you should have been in the first place. And the only way I know when a broken axle boot slings grease at the rotor. If you don't do this there is a good chance you will warp the rotors and at the very least have to be turned on a lathe when the weather warms up and more of the coating workes it's way back out of the pads. Cheers, GTM2U Link to comment Share on other sites More sharing options...
jl2 Posted January 16, 2006 Author Report Share Posted January 16, 2006 I've changed brakes many times on different cars over 25 years, including this very car last year, with no change in pedal travel. The new rotors were coated wth a light film of oil, exactly as they were last year (same brand, Brembo). No heavy films, no grease. As I usually do, I installed the new rotors after thoroughly cleaning them with brake cleaner and wiping dry with a clean shop towel. I did not see any grease or oil on any rotor surface, but I suppose there could have been some, although this has never before been an issue. I have never had to bleed brakes on any car during a routine change before. Last year (at 22k; the car now has 44k) I completely flushed the brake fluid using a power bleeder (works great), because the car was about 2 years old, using ATE Super Blue fluid. I had not planned to bleed again until next year, but did so because I was concerned about the long travel. After installation, I bled using the power bleeder; bleed tube was immersed at all times, fluid was mostly clean, no bubbles at all. Following this, I bedded pads and rotors as per SOP. The old pads were 95% gone.No warning light, brake performance is good, just long pedal travel. With 2 pumps, the pedal comes up higher and does not sink. Pedal feel is not spongy. am leaning towards a proportioning valve issue. Would you agree? Is there anything else I should think about? Is there a way to diagnose a proprotioning valve problem? If it is a proportioning valve, how can it be corrected?Thanks to all for your great help. Link to comment Share on other sites More sharing options...
howardc64 Posted January 16, 2006 Report Share Posted January 16, 2006 The new rotors were coated wth a light film of oil, exactly as they were last year (same brand, Brembo). No heavy films, no grease. As I usually do, I installed the new rotors after thoroughly cleaning them with brake cleaner and wiping dry with a clean shop towel. I did not see any grease or oil on any rotor surface, but I suppose there could have been some, although this has never before been an issue.Mine rotor was the same condition. Brambo with a very light film of oil which I cleaned thoroughly with brake cleaner. The "coating" I'm referring to is not something I think you can take off with a cleaner. When I say it looks like clear coat. It is a hard shinny surface. It isn't oily. Looks like the only way to get rid of this is to sand it (which I didn't do) Link to comment Share on other sites More sharing options...
jl2 Posted January 16, 2006 Author Report Share Posted January 16, 2006 Mine rotor was the same condition. Brambo with a very light film of oil which I cleaned thoroughly with brake cleaner. The "coating" I'm referring to is not something I think you can take off with a cleaner. When I say it looks like clear coat. It is a hard shinny surface. It isn't oily. Looks like the only way to get rid of this is to sand it (which I didn't do)I suspect that it is not any sort of rotor/pad problem for several reasons. First, I changed the brakes exactly the same way on the same car last year, with no problems whatsoever (in fact, I was surprised at how easily it went last year, given that it's a Volvo). Second, a pad/rotor issue related to a surface problem shouldn't cause an extremely long pedal travel. Brake performance is fine; I do not need excessive pressure to stop, and there is no sponginess, grabbing, skipping, pulsing or any other braking problem per se. Once the extra pedal travel is taken up, the car stops normally, in a straight line. I am going to check the front rotor/pad thing today, when I change the rears, but I doubt it's going to change. However, I will sand the rotors, since it can't hurt.Perhaps a tech on VS has a suggection? Link to comment Share on other sites More sharing options...
Guest Guest_jl2_* Posted January 16, 2006 Report Share Posted January 16, 2006 I checked out the rear brakes, which I was prepared to change. They look about 75%, and I'm going to leave them alone. I sanded the front rotors, which did not seem to have any sort of film on them whatsoever. No change. Pedal travel is still excessive, brake performance is fine. I suppose I can live with ir for a few weeks and see if the pedal improves, as mentioned above. However, I would like to be more proactive if possible.Can anyone suggest the next step?Thanks. Link to comment Share on other sites More sharing options...
MrWinkey Posted January 17, 2006 Report Share Posted January 17, 2006 The problem lies in your pads IMO....try taking it out and making the brakes hot... work' em ......get the car up to say 60mph and stand on them(the brakes that is )....and if the car doesn't stop like you think it should, do it again ...run for a 1/2 mile and stand on them....repeat as necessary....that is one of the problems with those good pads you really need to get them hot to scrub them in and make em' work ...but if they get better with heat there is the source of your problem B) Link to comment Share on other sites More sharing options...
jl2 Posted January 17, 2006 Author Report Share Posted January 17, 2006 The problem lies in your pads IMO....try taking it out and making the brakes hot... work' em ......get the car up to say 60mph and stand on them(the brakes that is )....and if the car doesn't stop like you think it should, do it again ...run for a 1/2 mile and stand on them....repeat as necessary....that is one of the problems with those good pads you really need to get them hot to scrub them in and make em' work ...but if they get better with heat there is the source of your problem I bedded the brakes and drove about 500 highway miles since installation last Thursday. No change in performance after initial bedding procedure. FYI, I used a C-clamp to slowly push the caliper cylinder back into the bore when I did the work. After finishing the job, I power bled the brakes. Could pushing in the cylinder have damaged any valves or orifices? Thanks. Link to comment Share on other sites More sharing options...
howardc64 Posted January 17, 2006 Report Share Posted January 17, 2006 Here is the solution to my "excessive brake pedal travel" problem. This was really a bone head mistake but seems easy to to make for a none pro. Perhaps my stupidity will help others.I simply didn't put on one of the retaining springs correctly. Rather than getting spring tension to keep the caliper from twisting, I clip it on the other side of the caliper bracket. The necessary tension is gone and the caliper twists during braking placing the pressure on the outer pads incorrectly.What showed up was the rotor showing radially tapered wear on the surface after a couple of weeks (inner surface rusty as if untouched). Looking at the gap between the pads and the outer rotor surface shows the taper clearly.Other easy symptoms are- The spring doesn't clip in perfectly. They don't fit into the hole on the ends perfectly.- The sliding pin holds the inside of the caliper to the bracket while the spring clip holds the outside. If not clipped properly, you can easily create twisting motion on the caliper with your hands after installation.- If someone step on the brakes while parked and have the tires off (like having a helper bleeding the brakes), you can see the slight twisting motion in the caliper. How much twist depends on how much loaded pressure from the pistons.Other than excessive brake pedal travel, I had no other symptoms. No pulling to one side, pulsing, noise, and braking power feels like it was available just deeper down the pedal.Anyways, now I know how a floating caliper works :-) The reason for the excessive brake pedal travel is- the twists causes the piston to get pushed back when not braking. This requires more brake pedal travel to send more fluid to move the piston further during braking.- only a part of the outer brake pads contacts the surface. Gradually, more percentage mate up the the rotor as the pad tapers off. This was the source of my brakes getting better with each passing day.Anyways, my dumb DIY none pro mistake. Lost a pair of $35 mintex pads. Hope this helps others on what seems like a simple mistake the first time you do this. Especially after a couple of hours into the job and getting a little careless.Not suggesting jl2 did my dumb mistake. But I thought it would be good to put my problem/solution under the heading "excessive brake pedal travel" which is exactly what happened to me.Ok, now I'll wait for the chuckles from the pros :-) Link to comment Share on other sites More sharing options...
GTM2U Posted January 17, 2006 Report Share Posted January 17, 2006 I've changed brakes many times on different cars over 25 years, including this very car last year, with no change in pedal travel. ... am leaning towards a proportioning valve issue. Would you agree? Is there anything else I should think about? Is there a way to diagnose a proprotioning valve problem? If it is a proportioning valve, how can it be corrected?Thanks to all for your great help. It would be unusual to have soft pedal but not impossible just changing pads. I've had dust boots partly come off and get partly trapped on top of the metal pad backing. This could cause the piston to be forced back into the cylr. I've had the square cut "O" rings want to cock in the cylr and then will rock back to a relaxed state when the piston retracts slightly. I rarely have ever used a "C-clamp" to force pistons in unless they were frozen. Most of the time a couple large screwdrivers will do the job or large "Chanel Locks" once the caliper is swung up. The C-clamp puts a heck of a lot of pressure and will displace a lot of fluid in a hurry. It is entirely possible that you have shoved the Proportioning valve piston to one end where it's now stuck However it may not be so far to one end that it does not activate the warning light if it doesn't fall into the detent. There is no easy way to diagnose this but you could try the old shock method with a hammer and block of wood. A plastic shot filled hamer won't do it, and you need to give if a few good smacks. The problem here is the fluid from one side will have to move to the other UNLESS you open the lines at the valve and have the brake pedal depressed with a jam stick holding it partly down. If the first couple smacks with the hammer doesn't do it then open both lines about 1/2 turn and try again with the hammer and wood and the jam stick on the pedal. These are a PIA to bleed once you have introduced air and any I've had to rebuild or replace have been pre-bled on the bench. But here is a trick that may work, release the jam stick and let gravity bleed one side. Snug up that fitting, pull one wheel, and pry so the piston retracts just a bit, this will purge air from the other line. Tap on the valve with your block of wood and then tighten both lines. If beeading and bleeding don't solve it and you are certain there is no air then I would suspect this valve Oh by the way I have never seen any valves on calipers to answer that question so no damage there. The Proportoning valve is not that difficult to service if you really have to open it up. I don't know if it steel or aluminum, just be aware that there are some sandpapers which should _NOT_ be used on aluminum becuse the grit will inbed in the aluminum and ruin pistons and seals. And for goodness sakes pre-bleed the unit on the bench using safe jaws in the vise, use a small block of wood to rap in the housing to get all the bubbles out even it it takes you 10 minutes it will save you time bleeding on the car. Put caps on all lines and fittings plus your jam stick holding the brake pedal partly down. One of the possible reasons the Proportioning valve piston gets off center is pushing the pedal to the floor too fast after replacing the pads. I prefer to pump about 1/2 pedal travel slowly until I get pressure just for this reason along with introducing a lot of small bubbles which take a long time to work out. Loaded the volvo parts program for you and looked at a picture of the caliper, not sure if the poster in # 11 means the "retaining spring" but he may have managed to not get this properly installed and is causing the pad to cock at an angle, I just can't tell from the picture. I am assuming you got the 2 locating pins along with the rubber bushings properly installed so the caliper is free to slide. Keep us posted on what you find. Cheers, GTM2U Link to comment Share on other sites More sharing options...
jl2 Posted January 17, 2006 Author Report Share Posted January 17, 2006 After perusing all the incredibly insightful thoughts and suggestions as a result of my posts, I decided to just check my brake pad install 1 more time, reviewing it step by step, before I started to dig deeper (KISS). Like howardc64 said...Not suggesting jl2 did my dumb mistake. But I thought it would be good to put my problem/solution under the heading "excessive brake pedal travel" which is exactly what happened to me.Ok, now I'll wait for the chuckles from the pros :-)No problem, howardc64, please DO suggest it, because that's EXACTLY what I did! After your post, I went back and looked at the spring clips again. I had placed the outer portion inside, instead of outside, the tabs on the caliper. That explains why they went on way too easy the first time. Took them off, put them back on correctly, and voila! Problem solved. Brake travel is normal, perfromance is outstanding (except the EBC Green Stuff pads put out as much dust as any others). This is my first Volvo, and after 25 years of DIY auto repair/maintenance on American and Japanese cars, I've got even more to learn. Makes life interesting, but with the guys on Volvospeed for back-up, I feel confident. Thanks again to everyone who responded to my pleas for help. VS rocks!!! Link to comment Share on other sites More sharing options...
howardc64 Posted January 17, 2006 Report Share Posted January 17, 2006 After perusing all the incredibly insightful thoughts and suggestions as a result of my posts, I decided to just check my brake pad install 1 more time, reviewing it step by step, before I started to dig deeper (KISS). Like howardc64 said...Not suggesting jl2 did my dumb mistake. But I thought it would be good to put my problem/solution under the heading "excessive brake pedal travel" which is exactly what happened to me.Ok, now I'll wait for the chuckles from the pros :-)No problem, howardc64, please DO suggest it, because that's EXACTLY what I did! After your post, I went back and looked at the spring clips again. I had placed the outer portion inside, instead of outside, the tabs on the caliper. That explains why they went on way too easy the first time. Took them off, put them back on correctly, and voila! Problem solved. Brake travel is normal, perfromance is outstanding (except the EBC Green Stuff pads put out as much dust as any others). This is my first Volvo, and after 25 years of DIY auto repair/maintenance on American and Japanese cars, I've got even more to learn. Makes life interesting, but with the guys on Volvospeed for back-up, I feel confident. Thanks again to everyone who responded to my pleas for help. VS rocks!!!Hey now we can have a good laugh at each other :-) But honestly, seems like a really easy mistake and no clear short term failure symptoms except for excessive brake pedal travel.I thought you might have done the same because we did the exact samething (power flush, brambo rotors, pads), have the same symptoms, and you seemed experienced enough to have cleaned the rotor reasonably + bled properly. Glad you didn't have to lose your pads like I did. Link to comment Share on other sites More sharing options...
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