Brakes or Lack of...

[classical glass]

On my ERA 427 I have the heavy-duty Sierra Calipers with the brake shoes that came with them???? My problem is I have to push quite hard just to slow down the car. I'm not by any stretch of the imagination a weak person. I need to do something before something bad happens. There is no way I could have a panic stop. I disassembled the front brakes totally and inspected everything. Pistons move smoothly no rust or dirt anywhere.There is positively no air in the lines anywhere. Also I have braided ss flex lines throughout the car. I'm running dot 3 brake fluid (fresh). I checked the bias on the new master cylinders and everything falls in specs. The back side of the pads have "Sierra 005 0455 Soft " I'm not sure if these are ceramic or not. Now I know more pressure is required because the brakes are not power assisted, but this is crazy. I'm going to brake specialist tomorrow to get his opinion on what's going on, but i thought I would ask the Forum first. Any suggestions????????
Thanks.

[Grubby]

You didn't mention the car number.

I have had the same set up and it works fantastic. Brake effort was similar to other cars I have driven without power assist.

Two suggestions;
Down load the ERA build manual and read the brake section carefully. It is a wealth of knowledge
Call ERA and ask some questions. They know these cars better than anyone.

John

[classical glass]

Originally Posted by Grubby

You didn't mention the car number.

I have had the same set up and it works fantastic. Brake effort was similar to other cars I have driven without power assist.

Two suggestions;
Down load the ERA build manual and read the brake section carefully. It is a wealth of knowledge
Call ERA and ask some questions. They know these cars better than anyone.

John

I have done both suggestions. I contacted several at ERA and they thought that maybe a different pad material. What pads are you using?

[Grubby]

I used the pads supplied by ERA on both front and rear. The rear pads were the standard OEM GM parts for Camaro?? calipers. I don't seem to have the information on the fronts. I think they were Wilwoods.

John

[patrickt]

Originally Posted by classical glass

I have done both suggestions. I contacted several at ERA and they thought that maybe a different pad material. What pads are you using?

I have the Sierra big brakes as well and I changed out the original Sierra "soft" pads, which were too hard for regular street driving, for Hawk Performance Pads #HB101F.800, which work spectacularly well on the street.

What I would suggest is that you change out the pads for the Hawk pads and perform a nice bleed (remembering there are four bleeder screws). Then, if you still have poor stopping, just change out the Tilton master cylinder for the front brakes. That's a really easy job to do and it'll cost less than a hundred bucks.

[classical glass]

Originally Posted by patrickt

I have the Sierra big brakes as well and I changed out the original Sierra "soft" pads, which were too hard for regular street driving, for Hawk Performance Pads #HB101F.800, which work spectacularly well on the street.

What I would suggest is that you change out the pads for the Hawk pads and perform a nice bleed (remembering there are four bleeder screws). Then, if you still have poor stopping, just change out the Tilton master cylinder for the front brakes. That's a really easy job to do and it'll cost less than a hundred bucks.

Patrickt Seeing that I have replaced both master cylinders I took your advise and ordered a set of Hawk brake pads from Summit Racing and should have them tomorrow. I really hope this helps with the braking issue. The car is not much fun to drive the way it is now. Thanks for the info.

[strictlypersonl]

Sometimes the pads get glazed when they aren't ever being used hard. They can be brought back by sanding the pad surface (and doing the same for the rotor).

[patrickt]

The beauty of the ERA big brake system is that there just isn't that much that can be wrong with it. Assuming your calipers and the master cylinders all work, and are bled, and you're now getting new pads that I know are good, the only other things that jump to mind are, maybe, that your brake balance bar is not set on the angle that the instruction manual outlines. I recall that it even stresses the fact that the front brakes require three times the fluid that the back ones do and it gives you a little picture of how it should look. And with the Sierra calipers you should have three shims between each wide spacer and the caliper ear. Make sure that the rotor is centered in the caliper to within .060" and, if it's not, then tweak it with shims until it is. You can add shims between the mounting bracket and the upright if necessary to try and get it within specs, but you shouldn't have to. If you do all that, then your brakes have to work, there's just nothing else that can go wrong, at least that I can think of.

[vntgspd]

I agree with the other comments here. This sounds like a glazing issue to me. I had the same issue with #347 when I got it because it was driven very sparingly over 20+ years. I have the standard brakes and they were scary at first but I found so many comments suggesting they were perfectly fine for road use that I decided to give them some time before upgrading. They have definitely improved since I have been driving the car.

If your rotor surface looks shiny or you can see a reflection up close, they are probably glazed and the pad can't get enough bite. The new Hawk pads should cut through this eventually or you may want to have the rotors turned to knock the glaze off.

[classical glass]

I have checked everything everyone has suggested and all checked out fine except for the pads being glazed. They look a bit shiny. I'm still going to replace the pads and rough up the rotors a bit. Thanks all for your time and the very good advice.

[patrickt]

Just to make sure your balance bar is not out of whack, I copied the picture from the ERA manual on what the threads on the balance bar should look like and below it is a picture of my set up. Yes, that's the way I grease things. Note the thread count difference on the two rod ends. The front cylinder has much more thread showing on its master cylinder than the rear does. If your two rods have the same threads showing, then your balance bar is likely not set up correctly.

[classical glass]

Originally Posted by patrickt

Just to make sure your balance bar is not out of whack, I copied the picture from the ERA manual on what the threads on the balance bar should look like and below it is a picture of my set up. Yes, that's the way I grease things. Note the thread count difference on the two rod ends. The front cylinder has much more thread showing on its master cylinder than the rear does. If your two rods have the same threads showing, then your balance bar is likely not set up correctly.

OK,Yes mine looks exactly like yours, I think it's set up correctly.

[classical glass]

Well I change out the brake pads per suggested, roughed up the rotors and bled the brake system for the tenth time. I now have twice the breaking ability than before. I seated the brake pads as instructed and the more I drive the car the better it's feeling.It's fun to drive this car again. Thanks for your input.

[patrickt]

Great. I love a post like that.

[vntgspd]

Good to hear. I think I'm going to do the same thing. My brakes are not as bad as you described but I drove my old 911 today and it stops SO much better than the Cobra despite similar weight and brake configuration.

Enjoy!

[my427cobra]

Hi classical glass. It has been often said by forum members and stated in pad instructions to "roughen the pads and rotors".

But I have yet to see specific instructions on how to do it.

Roughen by hand or by mechanical means (like a sanding disc on an sir tool)?

Grit of the abrasive used?

Cleaning instructions (Brakekleen or thinners)?

This info would be helpful.

Cheers
Greg

[Grubby]

I had GM training 20 years ago when I was a product engineer.

They suggested 80grit. I like to put the paper on a flat surface and run the pad over it until rough.

For the rotors I like a DA sander.

I typically use brake clean, but in a pinch I have used mineral spirits with no apparent ill effects.

Then as noted, bedding the brakes is critical. The auto manuals say do 10 x 40mph to 0 stops as quickly as possible without engaging ABS.

The current trend is to do 10 x 40 mph to near 0 stops. Don't come to a complete stop and then continue driving until the brakes cool some. There is some evidence coming to a stop can remove some of the brake material build up when the pads sit in one place on a super hot rotor.

Also note on my big braked ERA, it took nearly 20 x 40 mph to near 0 stops to get brake fade. That is how you know the pads are bedded. On my wifes Equinox, I got sufficient brake fade at 8 stops. You are looking for the brake fade not the number of stops.

John

[my427cobra]

Thanks John. Great description.

I'm out to the garage to install new pads.

Cheers
Greg

[Spyglass]

This is excellent information. I have the same problem with my brakes and was considering replacing my pads with softer ones. Did you guys change out front and rear pads or just the fronts?

Thanks
kevin

[Grubby]

If front and back are glazed then sand the front and back rotors and pads.

No need to replace unless they are thin.

John