Replaced rear calipers, reduced brake performance

[VK56VD]

My rear caliper was sticking so I replaced both my rear calipers with re-manufactured A1 Cardone calipers. While I was at it, I replaced the rear pads with Centric Ceramics and rear rotors with Centric Premium rotors with E-coating. Prior to replacement, my old pads were Nissan OEM and my rotors were Bendix Premium rotors. I bleed the rear brakes after installing everything. I now notice that the pedal travel is further than it was previous to the new calipers, rotors, and pads before the brakes start to really grab.

What can be the cause? Is it possible that I needed to bleed the front brakes as well?

 

[JHZR2]

if you open the system, its generally best to re-bleed the whole thing.

JMH

 

[VK56VD]

My mechanic told me that the front brakes and rear brakes work off of a separate system. Not sure if he's correct.

I can def. bleed the brakes again at all four corners. Other than air being in the system, can there be other factors as to why the brakes grab further down than they did before?

I was hoping the brakes would be stronger considering both rear calipers, brake pads, and rotors are new.

 

[The Critic]

Rebleed the entire system using this method:

http://www.zeckhausen.com/bleeding_brakes.htm

Then bed in the pads:

http://www.zeckhausen.com/bedding_in_brakes.htm

Check the condition of your brake hoses. Did you use new copper crush washers? A lot of pads will deliver a better pedal feel once they are bedded in.

 

[VK56VD]

These are rear brakes and will never get up to temperature. How should I bed in the rear brakes?

 

[The Critic]

Originally Posted By: Spartuss
These are rear brakes and will never get up to temperature. How should I bed in the rear brakes?

They will get up to temperature if you follow those instructions. We had someone on AcuraZine experience some noise with the Centric ceramics on the rear. After a bed-in session, even though no significant film was transferred, the noise went away.

 

[mechtech2]

The pedal won't be right until the pads/shoes seat in.
This can take a while, like up to 500 miles.
I assume you bleed technique and installation were proper.

 

[charbaby]

If you have never used ceramic pads then, you will notice a little difference in braking power when just installed,(smoother braking with a little less initial bite) until the pads seat/bed in properly. My opinion is to drive the car normaly as you would every day and I think that you will slowly notice that the peddal will start to become firmer and the braking power will increase over time. How much time depends on your driving style. Many people believe in making several, maybe 10 hard stop from a particular speed(30, 40 or 50 mph). I don't dissagree but, I don't use that method. Just drive and see what happens. Rebleeding also wouldn't hurt as JHZR2 has recomended.

 

[PT1]

Try 20 to 30 slow stops from 30mph to 5mph with some cooling of time (driving not stopped) and your pads will bed in nicely. I usually do 30 as a rule with new pads. Then I hit the freeway and do 5 60mph to 20 mph slow downs with a few cool off miles in between. Then you can actually see the pad material transferred onto the rotor.

 

[charbaby]

Spartuss,
How are you making out thus far? Any difference in the peddal feel and brake bite? Keep us posted!

 

[mechtech2]

Also, some pads are designed for hard use, and don;t grab well when cold or warm. They work best when HOT.
That is what those letters are on the pads or box - like EE or FF.
Kinda like multigrade oils, they are ratings for cold and hot performance.

 

[flanso]

I was told that bleeding brakes by pushing on the brake pedal causes the master cylinder piston to travel into the normally unused portion of the bore that is usually rougher, possibly damaging the piston seals. A vacuum bleeder was suggested as the alternative to that method. Opinions?

 

[The Critic]

Originally Posted By: flanso
I was told that bleeding brakes by pushing on the brake pedal causes the master cylinder piston to travel into the normally unused portion of the bore that is usually rougher, possibly damaging the piston seals. A vacuum bleeder was suggested as the alternative to that method. Opinions?

Don't know, but all of the factory service manuals that I've looked at (Nissan, Toyota, etc) have all said to pump to the pedal, hold down the pedal, open the valve until all of the fluid drains out, then tighten, release, and repeat.

 

[mechtech2]

If damage occurs when bleeding, you have pretty severe corrosion problems that are another subject.
This shouldn't be a problem normally, becuase there is no load or pressure to force the seal into unknown areas of abrasion [if they exist at all].

 

[VK56VD]

I did bleed the brakes again and the pedal is much firmer.

This vehicle does not have ABS brakes. If it did have ABS brakes, how do you flush out the ABS reservoir and is it necessary to do? Or is a flush via each caliper sufficient on a ABS equipped vehicle?

 

[flanso]

To clarify, on a good used master cylinder, the portion of the bore where the piston cup normally travels is shinier and smoother than the rest of the bore. When bleeding the conventional way, on the first pumps, the pedal goes down much further than usual forcing the piston cup into this less smooth portion of the bore. This, the person telling me said, caused some small but finite wear to the piston cup and that is why he recommended vacuum bleeding. It sounds plausible.