spongey brakes after pad / rotor replacement?
10-28-2017, 09:09 PM
#1
Junior Member
Thread Starter
Join Date: Oct 2002
Posts: 64
spongey brakes after pad / rotor replacement?
So I plan to do a bleed, but it seems pretty inconceivable to me that somehow air bubbles got into the lines from doing a rotor / pad replacement. But after doing it the brakes feel kinda spongey and you can floor the pedal with moderate effort. I would normally think air in there but it wasn't like that before and we didn't crack open any of the system. When spreading the calipers out I used one of these pumps to take out some of the fluid: https://www.harborfreight.com/gear-o...ump-61746.html
That's about it. How could air have gotten in there?
The car probably hasn't had a fluid flush in a long time anyway so I might as well bleed them, but is there anything else I should check? My only other thought is a sticking piston? The brake assembly was pretty straightforward so I can't imagine how it could have gone back together wrong but is there something that could be misassembled that could cause this?
That's about it. How could air have gotten in there?
The car probably hasn't had a fluid flush in a long time anyway so I might as well bleed them, but is there anything else I should check? My only other thought is a sticking piston? The brake assembly was pretty straightforward so I can't imagine how it could have gone back together wrong but is there something that could be misassembled that could cause this?
10-28-2017, 09:48 PM
#2
Senior Member
Join Date: Jan 2006
Location: Fuk 301 it's 410 Bal Md black/purple.
Posts: 1,860
The brakes only need to be bleed when the calipers are being replaced and if the brake lines are opened causing the air to creep in. A bad and a failing or leaking brake master cylinder can cause air to creep in also. The cheap brake pad and rotors can cause the car to feel like the car is not gonna stop. The new brakes and rotors have to be broken in.
10-29-2017, 12:52 PM
#3
Senior Member
Join Date: May 2012
Location: Long Island
Posts: 1,564
Did you BED them properly?
Look up the procedure.
Also, I've found with cars this old it's a good idea to do a complete power flush and bleed. It can bring new responsiveness to your brakes if they were bedded properly.
I've also found doing the fronts goes fine but when I do the rears, I've gotten similar issues. CS_AR has a thread about a home made power bleed device to do it by yourself.
Don't forget silicone grease everywhere there's a friction contact point and the backs of the pads where they meet the piston and frame on the other side (Other than the pad surfaces obviously) and inside the boots of the floating pistons. (Clean out the old grease).
Then it's a pro job with nothing to pick apart or question.
Do an entire flush and bleed and the Bedding if you haven't. Then you can put your ex friends through the windshield. LOL
Look up the procedure.
Also, I've found with cars this old it's a good idea to do a complete power flush and bleed. It can bring new responsiveness to your brakes if they were bedded properly.
I've also found doing the fronts goes fine but when I do the rears, I've gotten similar issues. CS_AR has a thread about a home made power bleed device to do it by yourself.
Don't forget silicone grease everywhere there's a friction contact point and the backs of the pads where they meet the piston and frame on the other side (Other than the pad surfaces obviously) and inside the boots of the floating pistons. (Clean out the old grease).
Then it's a pro job with nothing to pick apart or question.
Do an entire flush and bleed and the Bedding if you haven't. Then you can put your ex friends through the windshield. LOL
10-29-2017, 02:01 PM
#4
Senior Member
Join Date: Jan 2011
Location: Central AR
Posts: 3,041
11-05-2017, 05:46 PM
#5
Senior Member
Join Date: Mar 2010
Posts: 373
It could still happen, particularly if the pads were very well-worn and the fluid level went down a lot.
Regardless, you should still flush the fluid periodically. I like to do it whenever I replace the pads and rotors. Any quality brake fluid will be fine. Simply doing the brake fluid change is more important than what fluid you actually use.
Speed bleeders are awesome
Regardless, you should still flush the fluid periodically. I like to do it whenever I replace the pads and rotors. Any quality brake fluid will be fine. Simply doing the brake fluid change is more important than what fluid you actually use.
Speed bleeders are awesome