Brakes don't feel 100%?

[Yamahakid88]

Couple weeks ago I had my rear brake line go out, brought it to firestone because I didnt have the time to fix it. Before it blew brakes felt very good and firm, would stop on a dime. After I got it fixed it kind of feels like it isnt as powerful as before. I have to push way down on the brake pedal to get it to stop and even then it doesnt work to well. My rear brake rotors show normal wear, but my front rotors look like they are rusting a bit, even after I drive a good while. What could be the problem?

 

[Fivefingerdeathpunch]

I bet re-bleeding them would help.

 

[Scottydoggs]

id re bleed them too. mushy pedal = air in the lines.


or the master is going bad, look for wetness under it, where it bolts to the brake booster. if its wet the master is going bad.

 

[02NavyBlue]

Also it can leak internally. If they bled the brakes the manual way, sometimes that kills a master cylinder's internal seals(internal leak) Hold your foot on the brake pedal and see if it sinks after a while. If not, there is probably just air in the lines.

 

[Yamahakid88]

Ill try that Navy Blue. I wouldn't doubt there is air in the lines. What I get for bringing my car to a shop. I'll report back after school tomorrow. Thanks guys

 

[DruMor]

Also it can leak internally. If they bled the brakes the manual way, sometimes that kills a master cylinder's internal seals(internal leak) Hold your foot on the brake pedal and see if it sinks after a while. If not, there is probably just air in the lines.

What are you calling the "manual way" of bleeding brakes? One person pressing the pedal and other cracking open the bleeder until no air comes out? Why I'm asking is I just had my brakes all apart last week and after I put it all back together it seems a touch on the soft side, but one pump and they come up a lot harder. Without pumping once, I can still mash it hard enough to make the ABS kick on on dry pavement though. I'm going to re bleed everything for the heck of it to double check I got all the air out.

 

[Yamahakid88]

well I'm not really sure if there is an internal leak, it kind of sinks but not alot, sounds vague but do you get what I mean?

 

[Scottydoggs]

the res on the master will be low on fluid if its leaking.

a bad master can also make the pedal sink.


dont have a clue wtf 02navyblue is talking about, people have been bleeding brakes the old school way for a 100 years now. if the master is going bad leaking inside or not, that has to do with age and wear, not how they were bleed.

 

[02NavyBlue]

well I'm not really sure if there is an internal leak, it kind of sinks but not alot, sounds vague but do you get what I mean?

Yeah. Also you would notice a leak on the ground after doing that, and what scotty said

dont have a clue wtf 02navyblue is talking about, people have been bleeding brakes the old school way for a 100 years now. if the master is going bad leaking inside or not, that has to do with age and wear, not how they were bleed.

If brake fluid gets to the point where it starts getting dark, this type of sludge can form in the system on the lines and bores of cylinders/pistons. If it was building up in the master in a part where the pistons haven't gone in a long time(because the pedal isn't supposed to go to the floor, and usually doesn't for years), the seals will wipe past that sludge and it can degrade the seals.

 

[Scottydoggs]

good answer :th_thumb-up: never lost a master after bleeding tho.

 

[02NavyBlue]

Yeah if the fluid looks good, you should be fine. It's like mid nineties cars and farther back with the original fluid that poses a possible risk. There's a technique to put one foot under the pedal when manually bleeding just so you don't push it in that area.

Some car's brake fluid just gets bad fast. My neighbor's dodge neon blew a wheel cylinder, and when I replaced it and bled the brakes, the fluid looked like dirty motor oil, it was horrible. I don't know how it can get so bad so fast. It's like a late 90's.

 

[Scottydoggs]

heat is the only thing really.

brake fluid used to be treated like tranny fluid, you just keep it full. never serviced it.

 

[Yamahakid88]

It was hella dirty before the brakes blew, I wouldn't be surprised if it was the master cylinder. Could that be the reason why my front brakes dont seem to work well?

 

[02NavyBlue]

I suppose it's possible. First make sure there are no leaks, then make sure the proportioning valves are still in the rear lines(since you had the lines replaced, maybe the guys took them off and forgot to put them in the new lines), then I'd suspect the master is at fault.