vettebak

I was thinking about the springs in the rear calipers that supposed to always push the brake pads against the disk.
If u have removed the disk of the spindel ore replaced it.
U need to do a runout. If not u will get air in the caliper.
Bud what would happen if u take out the springs.
I drove lot of cars with bend disk. If u press the pedal u feel the pedal go up and down bud it still brakes and no air trouble.
If read that porsch has the same style brake set up with springs in them. And have the same issues and mechanics take the springs out. And have no troubles.

Did some one try this. Ore have a opinion on this.
If u take them out will the travel be so minor that u don't notice it.
Im curious about it

Thanks Leon

NeverTooOld

The purpose of the springs is to keep the pads firmly pressed against the rotor so debris can't get between them and cause scoring to the rotor or allow water to get between the braking surfaces. I recommend leaving them in.

Duke94

The springs stop what is called "knock back" where the rotor runout pushes the Pistons and lining back. When that happens, the first brake application the pedal will go to the floor. On new style calipers, they use a square cut seal that acts as a spring to roll back the piston and prevent knock back. Better leave them in.

JoeMinnesota

Does this mean that, if I have replaced rotors with stainless lined O-ring replacements, I don't need to be concerned about run-out?
Curious as I am replacing trailing arms now, will reuse my original rotors, and the calipers are the new upgraded parts. Thanks

vettebak

I understand the way you think bud why aren't they in the front calipers.
If the front rotors accumulate run out over time its no issue.
I don't think its to keep water and dirt out.
I think it would depend on how disform the disk will get or initial runout at the start.
I have bin told that u can leave them out and it would be fine.
I'm curious if someone has them out.
The o ring style seal I'm not sure if it really push it self out.
I think the lip seal will be less smooth as the o seal.
What do u think.

noonie

Duke94 is correct.

Porche never used lip seals for calipers.
Some of the o-ring conversion pistons don't have room for the springs anyway.
Correct your run out as best as possible to prevent low pedal.
The front rotors don't have this problem since turning the rotors/hub as an assembly eliminates the run out.

MelWff

Why do you have the mistaken impression that the front calipers dont have springs?

https://willcoxcorvette.com/corvette...ng-front-65-82

vettebak

Hmm intresting they are not in my front calipers.
When i rebuild them.
Didnt know they here equipt with springs.
Never had any trouble with it. Maybe the run out is correct i will check it. What the run out is now . Did the run out when i instaled them just to be sure.

gg521

I think you have been told some bad information. Yes, the less runout, the better the system. Lip seal a little more prone to air pumping than O ring seal. If bore is corroded, both will be less effective. Springs should be in both front and rear calipers.

lionelhutz

The C3 has fixed calipers with lip seals. The piston can get pushed in by the rotor having runout. The piston can also get pushed out by the spring. So, the pistons can move in and out following the runout of the rotor. Air will tend to go past a lip seal if you attempt to use it to pull brake fluid. So, this means the calipers are susceptible to pulling in air.

You want the springs to avoid pad and piston knock back, which means you need to eliminate the rotor runout. Being the front or rear makes no difference, both need minimal runout to work correctly.

Typically, most other cars have floating calipers so the whole caliper will follow the rotor when it has runout. No piston knock back happens. Also, the square seal used holds the piston much tighter so it can't be moved in the bore nearly as easily.

I've never seen another application where a brake caliper uses an o-ring, so I'm not sure why the aftermarket thinks that they are a better solution.

The stock C3 brakes are very good once they have been setup correctly.

noonie

1-Runout is just as much a problem with cars today
Here is one of hundreds of links
http://www.autoserviceprofessional.c...-issues?Page=2

2-Apparently you have forgotten the banter we went thru 4 years ago about the orings or solid rings or square cut or whatever you prefer to call them. Remember Girling 4 piston used on exotics started in the 50s and even Ford.
And even the round crossection orings are good to over 8000psi, only 1800psi panic stop braking system is child's play.
It was all addressed in that thread including the nomenclature.

Here is a link to that discussion
https://www.corvetteforum.com/forums...in-brakes.html

lionelhutz

Give it a rest.

I didn't post that runout with floating calipers doesn't cause any pedal pulsations. They can follow the rotor and not leak and not have excessive pad push back. But if you want to argue, with floating calipers it's more likely that pulsing will be caused by the rotor not wearing evenly so the rotor is no longer the same thickness all around.

Round profile o-rings are still not the same thing as the square cut seals used in modern calipers. You keep saying they are, but they are not....

And rubber o-rings are certainly not good to >8000psi for very long. We had to switch to a synthetic o-ring of some type in the quick connects of the hydraulic crimpers we use at work because the rubber ones would quickly tear apart and leak. We just happen to crimp at 8000psi and it's not a very high duty cycle application overall. The connectors never got separated or even moved between the installation of a new o-ring and it's failure either. I'm not sure what the new rings are made of. The local hydraulic company had them in stock and they are a blueish color so it's a synthetic material of some sort.