Brake problems?

gmonde · 02-20-2011, 01:54 PM

also check your brake pads for sitting in the brackets and calipers ,some times the aftermarket pads do not sit correctly and this will cause a spongy pedal due to the caliper piston flexing the brake pad and acts like a spring pushing the piston back in ,,,,if the master is bad the pedal will slowly make its way to the floor under constant brake pedal presure

to isolate the caliper(s) block off each wheel with line clamps (if you are using rubber hoses) check the pedal each time you remove one of the lines ,this will help locate the issue

gmonde

mopar · 02-20-2011, 02:13 PM

sound like to me , the master clyinder is your problem. ( not holding presser at all time)

Ron Waters 1346 s/st

art leong · 02-20-2011, 02:41 PM

I just went out and tried the brakes with the motor off.
When I pushed hard (2 feet) the pedal slowly sank.
When I tried it before I got a firm pedal and just figured it was good.
So now I'm pretty sure it's the master cylinder.

Phillip marvetz · 02-20-2011, 10:09 PM

Either the master cylinder or you have a small leak that is letting air in. Did you put in a hydraulic switch or pressure gauge? My vote is the master cylinder though.

chris ok · 02-21-2011, 02:49 PM

any time you bleed a used master cylinder you have to be careful to not bottom it out.
Are you moving to much volume of fluid? Don't manual brakes use a smaller diameter bore piston. One possibility.
Honda an some other companies screw their hat rotorrs to the hub. One screw w a tapered head, supposedly helps with the pedal. saw it saturday at work. they screwed it together and corrected a shimy and a pedal issue. These are lightweight rotors with heavy clamping on the calipers from your ratio and line pressure. second possibility
Any time I've taken brakes apart you always have to re seat them too.

art leong · 02-21-2011, 03:27 PM

I'm changing the master cylinder, And see if that helps.
I also am wondering if I used a bigger piston caliper (now 54mm change to 60mm).
Would this increase the static ( against the converter) holding? I'm not sure if a larger piston would increase the static holding with the same rotor?

Eddies66 · 02-28-2011, 07:27 PM

http://www.carcraft.com/techarticles...der/index.html

02-20-2011, 01:54 PM	#1
gmonde Senior Member Join Date: Nov 2007 Posts: 615 Likes: 56 Liked 165 Times in 59 Posts	Re: Brake problems? also check your brake pads for sitting in the brackets and calipers ,some times the aftermarket pads do not sit correctly and this will cause a spongy pedal due to the caliper piston flexing the brake pad and acts like a spring pushing the piston back in ,,,,if the master is bad the pedal will slowly make its way to the floor under constant brake pedal presure to isolate the caliper(s) block off each wheel with line clamps (if you are using rubber hoses) check the pedal each time you remove one of the lines ,this will help locate the issue gmonde

02-20-2011, 02:13 PM	#2
mopar Junior Member Join Date: Sep 2010 Posts: 11 Likes: 0 Liked 0 Times in 0 Posts	Re: Brake problems? sound like to me , the master clyinder is your problem. ( not holding presser at all time) Ron Waters 1346 s/st

02-20-2011, 02:41 PM	#3
art leong VIP Member Join Date: Dec 2001 Location: Richmond Hill, Georgia Posts: 2,003 Likes: 0 Liked 1 Time in 1 Post	Re: Brake problems? I just went out and tried the brakes with the motor off. When I pushed hard (2 feet) the pedal slowly sank. When I tried it before I got a firm pedal and just figured it was good. So now I'm pretty sure it's the master cylinder. __________________ Art Leong 2095 SS

02-20-2011, 10:09 PM	#4
Phillip marvetz Senior Member Join Date: Oct 2008 Location: Lynden ,WA Posts: 820 Likes: 0 Liked 3 Times in 3 Posts	Re: Brake problems? Either the master cylinder or you have a small leak that is letting air in. Did you put in a hydraulic switch or pressure gauge? My vote is the master cylinder though. __________________ 2009 V/SA Record Holder

02-21-2011, 02:49 PM	#5
chris ok Senior Member Join Date: Jul 2002 Location: Long Island, New york Posts: 592 Likes: 131 Liked 46 Times in 29 Posts	Re: Brake problems? any time you bleed a used master cylinder you have to be careful to not bottom it out. Are you moving to much volume of fluid? Don't manual brakes use a smaller diameter bore piston. One possibility. Honda an some other companies screw their hat rotorrs to the hub. One screw w a tapered head, supposedly helps with the pedal. saw it saturday at work. they screwed it together and corrected a shimy and a pedal issue. These are lightweight rotors with heavy clamping on the calipers from your ratio and line pressure. second possibility Any time I've taken brakes apart you always have to re seat them too.

02-21-2011, 03:27 PM	#6
art leong VIP Member Join Date: Dec 2001 Location: Richmond Hill, Georgia Posts: 2,003 Likes: 0 Liked 1 Time in 1 Post	Re: Brake problems? I'm changing the master cylinder, And see if that helps. I also am wondering if I used a bigger piston caliper (now 54mm change to 60mm). Would this increase the static ( against the converter) holding? I'm not sure if a larger piston would increase the static holding with the same rotor? __________________ Art Leong 2095 SS

02-28-2011, 07:27 PM	#7
Eddies66 VIP Member Join Date: Feb 2010 Location: Rancho Mirage, CA Posts: 1,308 Likes: 300 Liked 881 Times in 452 Posts	Re: Brake problems? http://www.carcraft.com/techarticles...der/index.html