Brake pulsing??
Thread Starter
Joined: Jun 2014
Posts: 1,241
Likes: 47
From: Noblesville, IN
Brake pulsing?? I have a weird somewhat intermittent issue. My brakes seem to be really off lately. Occasionally when i I step on the brake the car wants to pull in one direction of the other. Not consistently and not in any way I can predict.
On top of that, on other occasions as I get to slower speeds (10mph and below) I get a pulsing. Its not in the brake pedal but in the whole car. As if the brakes are grabbing hard, then loosing grip, then grabbing hard again. Almost makes me wonder if the rotors are warped and its causing the brakes to have less surface area to grip occasionally
On top of that, on other occasions as I get to slower speeds (10mph and below) I get a pulsing. Its not in the brake pedal but in the whole car. As if the brakes are grabbing hard, then loosing grip, then grabbing hard again. Almost makes me wonder if the rotors are warped and its causing the brakes to have less surface area to grip occasionally
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
Rotors usually cause a pulse from any speed and all the time. You may have an abs issue. Id try unplugging the abs fuse under the hood and see if the issues go away.
I had warped rotors and no my brakes did not cause a pulse from any speed and all the time.
they did pulse when braking hard though.
I went hard core and got the Wilwood 6 piston superlights and 2 pc rotors, had them on my car since 2007.
Brilliant.
they did pulse when braking hard though.
I went hard core and got the Wilwood 6 piston superlights and 2 pc rotors, had them on my car since 2007.
Brilliant.
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
MOST of the time when you have warped rotors, the pedal pulsing will happen DURING BRAKING from most speeds, every time. Variances DO occur!
The fastest I've gone in the car was 145. Slowing down from that speed was frightening with the current rotors to say the very least.
I'll hopefully be fixing mine soon, I'm getting a squeal from the drivers side at all times that kind of pulses with the brakes, so I'm assuming I need pads. I'm just going to replace the pads and rotors with the eBay specials that everyone seems to like.
Teching In
Joined: Apr 2012
Posts: 31
Likes: 0
From: Lower Sackville, NS, Canada
Sounds like it's got a caliper starting to sieze, or maybe a stuck slider or something. After next drive walk around and put your hand close to the caliper and compare to the other side. The rotors being warped would usually only shake when your foot is pushing the brake pedal
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My ABS is a little funky like that sometimes. It will pull to one side. All 3 of my ls1 Camaros were like this.
As far as the pulsing, I think warped rotors. You should be able to really tell at higher speeds. Then, that pulsing you describe can be noticed at slower speed, just like you said.
As far as the pulsing, I think warped rotors. You should be able to really tell at higher speeds. Then, that pulsing you describe can be noticed at slower speed, just like you said.
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TECH Apprentice
Joined: Apr 2007
Posts: 311
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From: South Carolina
IDK if this is would help you or not but my Lightnings brakes use to pulse on and off during heavy breaking. My fix was switching from a vacuum boost setup to a hydroboost setup. I've been extremely happy with Hydroboost. It's also great for running big cams.
I wold like to put this our there. Brake rotors do not typically warp. It does happen, but 95% of you have pad transfer onto the rotor. This can sometimes be corrected by re-bedding the pads.
I typically go a long back road. Do 5-6 60mph to 10mph maximum hard stops. Never stopping, accelerating to 60 again and repeat 5-6 times. Then drive 40-50 mph with out stopping for 5-10 minutes letting the brakes cool.
I have got rid of pulsing brakes this way many times.
The cause it typically a hard stop on an off ramp and sitting at a light with the brakes pressed causing pad material to be left in that spot on the rotor. This causes different friction in that spot. Hence the pulse.
If have to stop fast, I always stop short now and let the car creep to cool it more evenly and not transfer pad material. I have not had a pulsing brake in a decades since I change how I drive.
I typically go a long back road. Do 5-6 60mph to 10mph maximum hard stops. Never stopping, accelerating to 60 again and repeat 5-6 times. Then drive 40-50 mph with out stopping for 5-10 minutes letting the brakes cool.
I have got rid of pulsing brakes this way many times.
The cause it typically a hard stop on an off ramp and sitting at a light with the brakes pressed causing pad material to be left in that spot on the rotor. This causes different friction in that spot. Hence the pulse.
If have to stop fast, I always stop short now and let the car creep to cool it more evenly and not transfer pad material. I have not had a pulsing brake in a decades since I change how I drive.
here we go with the 'rotors don't warp theory' 
for a 10+ year old car that has never had the brake fluid changed, don't overlook a caliper having a stuck piston. replacing each caliper would not be a bad idea, at the least inspect each of your calipers by popping each piston out and inspecting their bores. otherwise you are taking your chances.
for a 10+ year old car that has never had the brake fluid changed, don't overlook a caliper having a stuck piston. replacing each caliper would not be a bad idea, at the least inspect each of your calipers by popping each piston out and inspecting their bores. otherwise you are taking your chances.
Here's my normal process when brakes act funky.
Pull the calipers off to expose the rotor.
Scrub the rotor braking surface with steel wool or abrasive pad (rotor manufacturer specifically said DO NOT USE SANDPAPER).
Scrub the pads contact area.
Check the calipers for smooth and correct operation (rebuild kits are cheap and easy DIY maintenance).
Put it all back together and rebed the brakes according to pad/rotor manufacturer. If they are different go by the rotor's instructions.
If this doesn't help then its time to buy rotors or have them turned to cut through the surface warpage. Technically it won't "fix" warped rotors but will help in most cases.
Cracked rotors need to be replaced ASAP before you hurt someone. Glazed rotors tend to warp due to altered metal density across the surface causing additional hot spots. Never replaced a set just because they had glazed, quick resurface keeps them going a while longer.
Pull the calipers off to expose the rotor.
Scrub the rotor braking surface with steel wool or abrasive pad (rotor manufacturer specifically said DO NOT USE SANDPAPER).
Scrub the pads contact area.
Check the calipers for smooth and correct operation (rebuild kits are cheap and easy DIY maintenance).
Put it all back together and rebed the brakes according to pad/rotor manufacturer. If they are different go by the rotor's instructions.
If this doesn't help then its time to buy rotors or have them turned to cut through the surface warpage. Technically it won't "fix" warped rotors but will help in most cases.
Cracked rotors need to be replaced ASAP before you hurt someone. Glazed rotors tend to warp due to altered metal density across the surface causing additional hot spots. Never replaced a set just because they had glazed, quick resurface keeps them going a while longer.