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huh..you learn somthing every day..this LR/RR/RF/LF is std for nearly all cars.
Do you know why its different for 01-04 vettes?..
Yup ... I'm cheating and pasting this from a previous response I made a while back ....
The reason for the two different bleed sequences .....
Let's take a simple example, a car with no ABS ..... it can be any car made after about 1960, by any manufacturer, so long as it was for sale in the US ...
If you look at the brake master cylinder, you will see that there are TWO feeds out from it, with each feed then splitting and going to an individual slave cylinder.
This is done so that, say, you suddenly have a massive failure of a single brake line .... that brake and the other brake controlled from that master cylinder feed will not work .... BUT ... you will still have two working brakes out of 4 .
Up until the 1990's the split was the front two brakes were serviced by one line and the rear brakes served by the other. Hence, you bled the brakes from furthest to closest.
On the Corvette, starting with the 2001 model, the split was made to be diagonal .... one front and one rear brake share one master cylinder feed, and they are diagonally opposed.
This was done for several reasons ...
With the old system, if you lost a front brake, all you had was the rears, and rear brakes only provide about 10 to 20 percent the stopping power of the front brakes.
By going with a front/rear split, if a brake fails, you will always have one working front brake .... much more stopping power than only rear brakes.
Finally, the split is diagonal so you don't end up getting a huge "pull" to one side or the other, the remaining brakes will be more "balanced" than two brakes on the same side of the car working with no offsetting brakes on the other.
So, that's why the change in the bleed sequence, the brake lines are routed differently today .....
Yup ... I'm cheating and pasting this from a previous response I made a while back ....
The reason for the two different bleed sequences .....
Let's take a simple example, a car with no ABS ..... it can be any car made after about 1960, by any manufacturer, so long as it was for sale in the US ...
If you look at the brake master cylinder, you will see that there are TWO feeds out from it, with each feed then splitting and going to an individual slave cylinder.
This is done so that, say, you suddenly have a massive failure of a single brake line .... that brake and the other brake controlled from that master cylinder feed will not work .... BUT ... you will still have two working brakes out of 4 .
Up until the 1990's the split was the front two brakes were serviced by one line and the rear brakes served by the other. Hence, you bled the brakes from furthest to closest.
On the Corvette, starting with the 2001 model, the split was made to be diagonal .... one front and one rear brake share one master cylinder feed, and they are diagonally opposed.
This was done for several reasons ...
With the old system, if you lost a front brake, all you had was the rears, and rear brakes only provide about 10 to 20 percent the stopping power of the front brakes.
By going with a front/rear split, if a brake fails, you will always have one working front brake .... much more stopping power than only rear brakes.
Finally, the split is diagonal so you don't end up getting a huge "pull" to one side or the other, the remaining brakes will be more "balanced" than two brakes on the same side of the car working with no offsetting brakes on the other.
So, that's why the change in the bleed sequence, the brake lines are routed differently today .....
Good question
Kewl..thanks..
Im betting this is why so many people have problems when they bleed their brakes
Last edited by BitViper; Jul 16, 2008 at 03:59 PM.
Im betting this is why so many people have problems when they bleed their brakes
And it's not just the Corvette that has this new bleed sequence .... but since most people won't RTFM you'll be hearing more complaints about how hard it is to bleed brakes ...
The factory bleeds the brakes by pulling a vacuum on the entire system, then when under total vacuum, introduces the brake fluid. This totally eliminates air, and thats why a good factory brake pedal is very hard to duplicate in pedal feel. In the new HHR SS, there are is a Brembo brake option coming up, with the first ones dealer installed. The Info sheet cautions that conversions done outside the factory will not have as good a pedal feel as the ones that come done in the factory for that same reason.
Yup ... I'm cheating and pasting this from a previous response I made a while back ....
The reason for the two different bleed sequences .....
Let's take a simple example, a car with no ABS ..... it can be any car made after about 1960, by any manufacturer, so long as it was for sale in the US ...
If you look at the brake master cylinder, you will see that there are TWO feeds out from it, with each feed then splitting and going to an individual slave cylinder.
This is done so that, say, you suddenly have a massive failure of a single brake line .... that brake and the other brake controlled from that master cylinder feed will not work .... BUT ... you will still have two working brakes out of 4 .
Up until the 1990's the split was the front two brakes were serviced by one line and the rear brakes served by the other. Hence, you bled the brakes from furthest to closest.
On the Corvette, starting with the 2001 model, the split was made to be diagonal .... one front and one rear brake share one master cylinder feed, and they are diagonally opposed.
This was done for several reasons ...
With the old system, if you lost a front brake, all you had was the rears, and rear brakes only provide about 10 to 20 percent the stopping power of the front brakes.
By going with a front/rear split, if a brake fails, you will always have one working front brake .... much more stopping power than only rear brakes.
Finally, the split is diagonal so you don't end up getting a huge "pull" to one side or the other, the remaining brakes will be more "balanced" than two brakes on the same side of the car working with no offsetting brakes on the other.
So, that's why the change in the bleed sequence, the brake lines are routed differently today .....
Good question
I know you’re probably driving a new C8 nowadays and have all but forgotten us webelows that are just getting into our first C5. Nevertheless, I would like to thank you for the information you left in the stone for others to see.
I’m about to bleed my brakes, and while looking at various techniques I heard one guy mentioning the sequence you described. That’s when I jumped on the forum for verification. What you shared not only verified my belief, but also explained why it was done in that seemingly odd sequence. I’ve written it down in my C5 notebook, and now more confident that I will complete this task correctly. Not to mention another intricate detail that made the C5 what it was and is to all that love them. Thanks again!
Contrary to a 12 YO post, The bleed sequence did not change because 01-04 wend to a "diagonal" brake configuration. See the photo below of the 2002 FSM hydraulic schematic. If you trace the normally open solenoids, you will see that the rear line from the MC feeds the RF and LF brakes and the front MC line feeds the LR and RR brakes. This never changed for the C5 gen, and I'm pretty sure through the C7 gen as well.
Why the RRvsLR first was changed, who knows. The lines from the ABS to the rear follow each other down the driver side of the torque tube tunnel and then come close together over the center of the diff. If you have to drop the diff, you can lift all the line restraints and spread these brake lines to lower the diff without cracking any fittings. So, the RR line is probably a foot longer than the LR line due to routing, but that is it. If you follow the FSM procedure, it has you gravity bleed the ABS fittings. If you do that, it really shouldn't matter at all about sequence,as the individual lines are separate from ABS on. 01 to 04 has dynamic brake proportioning, while 97-00 had a proportioning valve in the rear brake circuit. This changes the ABS logic a bit , and may be another reason why the sequence was changed.
I could be way off base, but I think that part of the equation, with respect to "bleeding the brakes", would depend on whether or not you're starting from scratch, with a "dry" system. I've had my C-5 since it was brand new (19 years), and have religiously changed the brake fluid every other year. As most of us know, the "new" plastic reservoirs have internal baffling, as well as "dropped" zones, that don't allow for a complete removal of the old fluid. Therefore, I do the best that I can, to draw as much of the old fluid as possible, then top off with fresh fluid, and attach my pressure bleed jug, but only with air pressure.
I then go to each bleeder, and let fluid flow until clear fluid runs out. However, old habits die hard, and I've always used the "traditional" sequence of RR, LR, RF, LF. Since I do not let the reservoir ever run dry, I don't see how it would make any difference, and FWIW, I've never experienced any issues.
