KenP Posted March 3, 2012 #1 Posted March 3, 2012 Recently I replaced both front rotors with EBC drilled ones, along with new brake pads. I noticed when I tighten the axle nut to the specified 72 ft/lbs. of torque, the wheel does not spin freely. I follow the order of tightening the different areas that the manual recommends. When I put the nut on hand tight, it does spin somewhat freely, but still binds, just less than when I tighten it down. I do have an upgraded fork brace installed. Braking all around is much improved over the stock rotors, however I am just concerned that the binding btwn the rotors and pads will do some damage. Anyone have experience with this issue??
bongobobny Posted March 3, 2012 #2 Posted March 3, 2012 the issue is probably with the calipers not completely retracting most likely due to buildup of crud on the pistons. First you will want to remove the calipers and then torque down your axle and see if the binding goes away. This will confirm that the issue is a clearance issue and not a wheel bearing issue. If it is indeed a caliper issue then there are 2 options. Either rebuild the calipers or sand down the pads a tad to give you the needed clearance. There is a third possibility and you need to determine which caliper is hanging up worse. As you are aware, the front master cylinder controls one caliper and the rear master controls the other. There may be something restricting the return flow of hydraulic fluid to the master. When was the last time the brake system was flushed?? On the rear controlled one the occlusion may be in the proportioning valve...
Marcarl Posted March 3, 2012 #3 Posted March 3, 2012 the issue is probably with the calipers not completely retracting most likely due to buildup of crud on the pistons. First you will want to remove the calipers and then torque down your axle and see if the binding goes away. This will confirm that the issue is a clearance issue and not a wheel bearing issue. If it is indeed a caliper issue then there are 2 options. Either rebuild the calipers or sand down the pads a tad to give you the needed clearance. There is a third possibility and you need to determine which caliper is hanging up worse. As you are aware, the front master cylinder controls one caliper and the rear master controls the other. There may be something restricting the return flow of hydraulic fluid to the master. When was the last time the brake system was flushed?? On the rear controlled one the occlusion may be in the proportioning valve... I think you got it right this time Bob!!
Brake Pad Posted March 3, 2012 #4 Posted March 3, 2012 I have the some issue, (2007), my front right pads, slightly touch the rotor, the wheel does not spin freely. wondering if it is something I can fix ( never did a fluid flush). is there a follow a picture post on how to clean the calibers????? and what do I clean them with, I plan to blow air in all areas, but what lube, do I use?
Condor Posted March 3, 2012 #5 Posted March 3, 2012 Another possibility other than the blocked return is the rotors may be a tad thicker, or a little off center causing the outboard pad to drag a bit after torqueing the axle. I had the drag problem with new EBC pads on the '83. After riding it a while the pads wore down enough to give some clearance off the rotor. It didn't take all that long to spin freely again. The same may hold true because of the new rotors??
jasonm. Posted March 3, 2012 #6 Posted March 3, 2012 (edited) I think you got it right this time Bob!! Assuming the caliper pistons were properly pushed back and did not lose a spacer. Then...I agree with Bob. AND Before changing pads. You should ALWAYS use a tooth brush and WD40 to clean the dust and muck that may be around the caliper pistons. THEN push pistons back. Now if you did not do this. Not to worry. Remove the caliper and pads...push on the brake lever...watch the pistons move out. If they are not coming out evenly. Use a small C-clamp w/1/4" plate steel to hold the non-sticky ones back as you press on the brake lever. Once one side pistons are moved out about 10mm to where you can see end of the "muck". Do the WD40 with tooth brush. I recommend exposing one side of piston(s) at a time. This 1/4" piece of flat steel works great to hold one(83-85) or 2 pistons(86-93) back Oh, don't forget the keep that steel in there or something to allow you to push the piston(s)back. wiuth that same c-clamp. Fyi, new pads will always have some drag. But with new rotors which are not grooved up...should be minimal. Edited March 3, 2012 by jasonm.
KenP Posted March 3, 2012 Author #7 Posted March 3, 2012 Thanks for the tips.....those calipers are probably original and should be reworked. I do have new synthetic fluid in the lines and flushed the old fluid out last year. Looks like a have a new project...... Ken
greg_in_london Posted March 3, 2012 #8 Posted March 3, 2012 I might be paranoid, but I wouldn't use WD40, I'd rather use brake fluid or chain cleaner or something similar that I know won't affect the rubber seals to clean the pistons. I could just be being overly cautious though. Is it actually likely that the EBC discs are THICKER than the originals though ? With the original ventilated discs being 1/2" thick, some of the aftermarket ones look like they're the standard 7-8mm in the pictures. It might be an obvious thing to say, but if you have it all bolted up without the pads themselves, can you check that the offset is right ?
KenP Posted March 3, 2012 Author #9 Posted March 3, 2012 I'll take the calipers off, torque it and check the clearances. If that is OK, then I'll rehab the calipers.....
jasonm. Posted March 3, 2012 #10 Posted March 3, 2012 I might be paranoid, but I wouldn't use WD40, I'd rather use brake fluid or chain cleaner or something similar that I know won't affect the rubber seals to clean the pistons. I could just be being overly cautious though. Is it actually likely that the EBC discs are THICKER than the originals though ? With the original ventilated discs being 1/2" thick, some of the aftermarket ones look like they're the standard 7-8mm in the pictures. It might be an obvious thing to say, but if you have it all bolted up without the pads themselves, can you check that the offset is right ? I put EBC rotors on my '87 they are approx. 7mm thick like the 86-93 series. Calipers on bikes have 2 seals , dust and hydraulic. WD40 will not hurt the rubber DUST seal. Yes, during rebuild, the hydro seal should be lubed with brake fluid. I have done this WD40 many times...the seal does not swell ...it's just used as a cleaner. As brake fluid has NO detergents in it, and using BF won't get you far sometimes in simple cleaning that is needed.
greg_in_london Posted March 3, 2012 #11 Posted March 3, 2012 I said I might be being overly cautious.... An old toothbrush and brake fluid cleans the crud off pretty well though - just try not to let it splash on your clothes.
jasonm. Posted March 4, 2012 #12 Posted March 4, 2012 I said I might be being overly cautious.... An old toothbrush and brake fluid cleans the crud off pretty well though - just try not to let it splash on your clothes. another reason to use WD40
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