Brake question

[bobcowan]

Originally Posted by Jaydee

I went from a 3/4 to 1 inch as the pedal ran out of travel. Now it takes a lot of pressure to stop it. I'll be going to instal a booster. Now the booster guy says to install a 3/4 inch booster which will double the pressure. But doesn't mean I'll be running out of pedal again? JD

Maybe. Depends on how long/deep the MC is, and what your pedal ratio is.

[classical glass]

Well I had both front calipers gone through and rebuilt. No real issues found I guess now it's just peace of mind. My whole braking system is now rebuilt so if i don't have more braking now it's the way God want's it. I can't take it out since there is 2 ft of snow in my yard so I guess I'll have to wait for better weather. Thanks to everyone for their input on this matter.

[66gtk]

Originally Posted by classical glass

Well I had both front calipers gone through and rebuilt. No real issues found I guess now it's just peace of mind. My whole braking system is now rebuilt so if i don't have more braking now it's the way God want's it. I can't take it out since there is 2 ft of snow in my yard so I guess I'll have to wait for better weather. Thanks to everyone for their input on this matter.

The bleeding process is NOT simple. There is a technique to it. ERA will tell you about a series of jacking up each side of the car in a certain progression. My mechanic created his own tool to help since we do these regularly and we don't have to jack up the car in strange sequences (:

I had a car that was built 20 years prior to me owning it. We determined that the rear brakes were never working since new, because they were never properly bled. There was NO wear on the rotors and the pads were like new still. After replacing the hoses and front to back line we still couldn't get fluid to easily pump back there until we isolated the rear MC and pumped away at it. That did the trick and then we were able to bleed all the brakes as a system and the rear brakes were working!

The key is to loosen the balance bar and bleed each master cylinder separately to make sure they are both pushing clean fluid all the way through and without any air bubbles. Bleed the clutch while you are at it. Do you have a single reservoir or 3 individual cans?

Troy

[classical glass]

I have the 3 reservoir cans. The calipers were cleaned and gone through as stated in my post. Before we re mounted them the brake shop gave me blocks that were about the thickness of the rotor. The calipers were then bled while off the mounting brackets with the bleeders straight up. We used a electric vacuum pump and pressure bled them multiple times. Also I have speed bleeders on all calipers just to be sure. I'm very confident that there is no air in the lines. After all this work I can't test drive it for a while or until 18" of snow melts in my neighborhood.
Thanks.

[66gtk]

Originally Posted by classical glass

I have the 3 reservoir cans. The calipers were cleaned and gone through as stated in my post. Before we re mounted them the brake shop gave me blocks that were about the thickness of the rotor. The calipers were then bled while off the mounting brackets with the bleeders straight up. We used a electric vacuum pump and pressure bled them multiple times. Also I have speed bleeders on all calipers just to be sure. I'm very confident that there is no air in the lines. After all this work I can't test drive it for a while or until 18" of snow melts in my neighborhood.
Thanks.

I have never had the girling cans, but I have heard some stories that they can leak and become troublesome. If you are getting plenty of fluid while bleeding and it seems to flow equally front vs back while pumping the pedal while bleeding you should be OK. Did you notice that one or more of the calipers seemed to be struggling more to get fluid to flow out?

[patrickt]

The reservoirs are not the problem. I had one leak completely dry and the brakes still worked fine because the fluid in the line leading from the MC, which has a tiny reservoir of its own, was sufficient to keep air out of the system. They are prone to leaks though.

Classical Gas -- have you reviewed the installation instructions found here: http://www.erareplicas.com/427man/br...conversion.pdf paying particular attention to the .060" centering requirement, shimming, and caliper bleeding eccentricities?

[classical glass]

Well the weather finally made a turnaround and I took my car out for a test drive. After all the work previously described not much has changed still poor stopping power. The only thing left is the balance adjustment. I read the assembly operating manual for instructions but it's a bit vague. Can anyone explain the proper way to adjust the brake bias. It's the only thing left that can cause poor braking.
Thanks

[66gtk]

Originally Posted by classical glass

Well the weather finally made a turnaround and I took my car out for a test drive. After all the work previously described not much has changed still poor stopping power. The only thing left is the balance adjustment. I read the assembly operating manual for instructions but it's a bit vague. Can anyone explain the proper way to adjust the brake bias. It's the only thing left that can cause poor braking.
Thanks

http://www.erareplicas.com/427man/brakes/
If you bled your system with the vacuum bleeder and NOT the pedal you do not yet know if your pedal is pumping fluid in proper ratios front/back. Start by making sure fluid is getting to all the calipers by bleeding the old fashioned way with the pedal. Your speed bleeders should allow you to do this without a helper required.

Also, see my questions I asked way back on response #8 to this thread.

[classical glass]

[quote=66gtk;1458025]What chassis number is your car? what wheels do you have?
I have owned several ERA cars and they all stop very confidently when properly setup. I suspect many (like a few I've had) are improperly set up. Some are never right from the start. You may think you have all the air out and the balance bar setup, but you may not. Did you also replace all the rubber lines from the reservoir to the MCs? Hard line from front to back as well as front and rear brake hoses? Depending on the age and miles (lack of use) these areas may all need to be addressed.

Chassis # 823, 6 pin knock off all new SS braided hoses, new 7/8 master, dot 4 brake fulid, speed bleeders vacume blead and pressure (break pettal) calipers were checked out at a local break clinic rotors turned etc. There isn't, much left. The break pedal is rock hard and oh yes new softer brake pads.

[66gtk]

With that new of a car I would not expect brake line/hose issues. Is this braking issue a NEW problem, or has it been like this since from the start? Did ERA assemble the car, including the brakes?

[classical glass]

Originally Posted by 66gtk

With that new of a car I would not expect brake line/hose issues. Is this braking issue a NEW problem, or has it been like this since from the start? Did ERA assemble the car, including the brakes?

Factory built car, this issue has been there since day one.

[DanEC]

Well - I may be completely off base but since I didn't find anything about your prior experience in older, manual brake cars, I wonder if it may be your expectation the ERA will brake like a new car. I have a 66 manual brake Vette and the old GM engineers have said several times over on Corvette Forums that the car has a high level of braking performance, even compared to newer cars, but they were designed in an era when higher pedal pressure was the norm for their engineering departments. In other words - you really have to really stomp on the brakes and when you do they will haul you down. That was how they were designed then. When I picked up my new GT350 Shelby, ever time I barely touched the brake pedal for about a month, it threw me against the seat belt until I got used to them. It's all a matter of pedal ratio, MC size, piston area and power/no power assist. Possibly Bob can weigh in the ERA design.


I may be off-base on this and maybe something is wrong. Sounds like you may need to step down slightly in size on the master cylinder piston diameter and live with a bit longer brake pedal stroke for a bit easier pedal pressure - and hopefully improved response.

[strictlypersonl]

Things I would check:

Make sure that the outer pushrod (to the front master cylinder) is the longer one.
De-glaze the pads and the rotors.
Break in the pads by repeated hard stops.

[66gtk]

If it was a factory turn-key car my understanding is that they put some shake down miles on these before delivery to make sure everything is working right. I would assume this means testing and breaking in the pads/rotors??? This car was one of the last completed, so I would think it would still be fresh in the minds of those at ERA who did the final assembly and sorting?

[classical glass]

Originally Posted by DanEC

Well - I may be completely off base but since I didn't find anything about your prior experience in older, manual brake cars, I wonder if it may be your expectation the ERA will brake like a new car. I have a 66 manual brake Vette and the old GM engineers have said several times over on Corvette Forums that the car has a high level of braking performance, even compared to newer cars, but they were designed in an era when higher pedal pressure was the norm for their engineering departments. In other words - you really have to really stomp on the brakes and when you do they will haul you down. That was how they were designed then. When I picked up my new GT350 Shelby, ever time I barely touched the brake pedal for about a month, it threw me against the seat belt until I got used to them. It's all a matter of pedal ratio, MC size, piston area and power/no power assist. Possibly Bob can weigh in the ERA design.


I may be off-base on this and maybe something is wrong. Sounds like you may need to step down slightly in size on the master cylinder piston diameter and live with a bit longer brake pedal stroke for a bit easier pedal pressure - and hopefully improved response.

Hi, I run a corvette restoration shop specializing in 53-67 Corvettes. I have a good feel on what non power brakes are like. My Cobra is nothing like that. I have a 57, 58 fuel injected and a 67 427 430hp.I can lock up the brakes on all of them. That could not happen with the Cobra. I'm believing the problem lyes with the rotors. They feel too smooth and after 50 or so miles they should show some kind of skuff or circular wear pattern.I'm thinking the new shoes are not being broken in properly. I've done everything else that I could think of. One thing is for sure I will not drive this car until I get good brakes.
Thanks

[patrickt]

Originally Posted by classical glass

Hi, I run a corvette restoration shop specializing in 53-67 Corvettes. I have a good feel on what non power brakes are like. My Cobra is nothing like that. I have a 57, 58 fuel injected and a 67 427 430hp.I can lock up the brakes on all of them. That could not happen with the Cobra. I'm believing the problem lyes with the rotors. They feel too smooth and after 50 or so miles they should show some kind of skuff or circular wear pattern.I'm thinking the new shoes are not being broken in properly. I've done everything else that I could think of. One thing is for sure I will not drive this car until I get good brakes.
Thanks

You mentioned in Post #9 that your rotors do not look like mine. Why don't you just pull them off and have them turned and see if that makes a significant improvement? We know the big brake design works, so it's just a case of figuring out which component of yours is faulty -- and there's not that many pieces in the puzzle. Turning the rotors is a cheap and easy shot in the dark.

[Jerry Clayton]

Change the lines front to small master --------

[patrickt]

Originally Posted by Jerry Clayton

Change the lines front to small master --------

I see from your first post you already turned the rotors, bled everything, and replaced the pads and master cylinders and worked with the balance. I agree, change the lines. Maybe there's a crimp or something in them that you can't see. Other than changing the calipers themselves I think that's all of the components. If you replace every component and an otherwise known-to-be-reliable brake system still doesn't work, then I would put it on a flatbed and send it up to the boys at ERA and just tell them you're stumped. It happens.

[Jerry Clayton]

a couple of necessary tools for solving severe brake issues on race or exotic(sporty) cars are scales and pressure guages----if you don't know the balance issues or line pressures, you might as well just get on the internet!!!!!!!!!!!

AND------if your trying to stop-pushing in the brake pedal will take away several HORSEPOWER ( even at idle) from the energy you are trying to overcome-------and if you happen to have an engine with a high idle speed -------say 12 -1500 rpm??????????

[strictlypersonl]

Originally Posted by Jerry Clayton

a couple of necessary tools for solving severe brake issues on race or exotic(sporty) cars are scales and pressure guages----if you don't know the balance issues or line pressures, you might as well just get on the internet!!!!!!!!!!!

The thing is, ERA has successfully used exactly the same setup for many years on hundreds of cars. All the components out to the calipers are included in the basic kit. No further engineering is necessary. If it doesn't work well, there's something wrong in the individual setup.

AND------if your trying to stop-pushing in the brake pedal will take away several HORSEPOWER ( even at idle) from the energy you are trying to overcome-------and if you happen to have an engine with a high idle speed -------say 12 -1500 rpm??????????

These are not power brakes with a vacuum booster.