Let's talk brakes 🙈

[teamzr1]

Brake pedal can be pumped countless times, but that does not move the old fluid out the ABS pump and its fluid tank volume
Not doing a correct process of using like a OBD-II scanner or a Tech-II sends commands to each wheel's ABS solenoid to open
so the fluid for the wheel being flushed
Not doing so means the first time ABS is commanded ON by the EBTCM, the old fluid is mixing (with the water it may have) with new fluid

If bleeding system and not the ABS
Air in your ABS brake will cause the brake pedal to feel spongy, and the air will have to be compressed before the pressure is applied to the brakes.
Bleeding an ABS module will help to remove the air in the system, making your brake system more responsive.

This is Nick's C5 ABS unit, so can be seen how much older fluid can be in it

As to swapping to braided hoses, many may have been coated and hence when installed to the end fittings may not then have a ground
path that the speed sensors need for ABS and traction control, so lots safer to test to be assured the ground path is these

Stock hoses have a ground braid in them to provide that ground path

 

[Stingray]

Braided lines look nice and that's fine. It's pretty unlikely they'll enhance brake performance over rubber since almost no manufacturers feel the need to fit them as OEM.

C5 braking from very high speeds is indeed limited. The issue I had was glazed discs, which can cause a "warped discs" vibration through the pedal, although happily the glazing wears off after a period of normal driving.

My recollection is that braking a standard C5 in anything other than a dead straight line was always a challenge due to "dive" in the front suspension. I suspect brake enhancements would need to be accompanied by suspension improvements to get the best out of them.

 

[teamzr1]

My 1999 C5 still has the original calipers and hoses
I do use slotted rotors and better pads

In doing Open Road Races such as the Big Bend out of Fort Stockton, Texas, the total distance is 120 miles in 90ish F degree weather
and averages 1 (mostly blind) turns with elevation changes per mile, so that is 120 turns at speeds from 130 to 220 MPH
I am a down shifter so not as hard on brakes but even so have no issues of braking at those speeds

Since the front brakes are larger can cause front to rear weight shifts, but some can be handled by the size
of the sway bars and shocks settings

If wanting less front brake bias can add an adjustable bias unit and then dial in as to road conditions and speeds
and change the front/rear bias on the fly

 

[Roscobbc]

Braided lines look nice and that's fine. It's pretty unlikely they'll enhance brake performance over rubber since almost no manufacturers feel the need to fit them as OEM.

C5 braking from very high speeds is indeed limited. The issue I had was glazed discs, which can cause a "warped discs" vibration through the pedal, although happily the glazing wears off after a period of normal driving.

My recollection is that braking a standard C5 in anything other than a dead straight line was always a challenge due to "dive" in the front suspension. I suspect brake enhancements would need to be accompanied by suspension improvements to get the best out of them.

Can't speak for other vette marques than C3's but its generally accepted that the braided hoses certainly do 'sharpen-up' the brake feel.......now whether that's due to the hoses on many C3's and earlier cars being a good few years old and well past their best.......admittedly the old hoses on mine did appear to be a little........er' swollen. Irrespectively if was a good move, as were the aftermarket disc pads.......really surprised the (presumably) OEM pads (rather like BF Goodridge tyres) would ever needed replacement during the life of the vehicle........so poor was the level of retardation. The total lack of brake dust on the wheels was another clue as to how useless they were.......lol!

 

[Krusty]

To end this debate, I have aftermarket suspension, aftermarket roll bars and aftermarket drop links all set up by a reputable suspension specialist not far from me. The car corners flat and dive is minimal in any braking scenario.
I have drilled and vented discs all round.
I have DOT 5.1 fluid which is of no further debate... it's better than DOT 3 and/or 4.
I have standard pads and they give no issues with my brakes, they work fine and I'm happy with the stopping power they produce even from high speeds.
I have no issue with how the car performs overall, for what I want from it and the occasional amount of 'spirited' driving I give it. I don't track the car and I don't race it about... I simply like to give it a good kick now and then when the overall conditions of time, place and weather allows me to do so. But I have no confidence in the FEEL of my brake pedal!
All my other cars feel sharp, responsive and give great feedback through the pedal whichgives you the confidence to brake late and feel what is going on.
Again, the Corvette brakes are fantastic and stop amazingly also! but I just have no confidence in the FEEL of the brake pedal (not the brakes themselves) comparing it to my other cars. It feels light in operation, as if the brake booster is amazingly good.
So can we please stay away from all of this discussion now as I'm repeating myself over and over... the car does not have a braking problem! That's not what I'm asking.
I want advice on a firmer pedal... that's all.
I know the difference between a 'spongey' pedal and a 'light' pedal. This pedal is light. It is very easy and comfortable to use compared to other cars... but it's so light, as I've mentioned over and over again, I have no confidence in the 'FEEL' of it! I want to feel more of what's going on when I'm braking
That doesn't mean it's 'spongey' OR boiling its fluid OR air in the system OR not braking efficiently OR whatever else has been thought of that I haven't said, because their isn't an issue...
So AGAIN, I simply ask what mods can be done to achieve a firmer, more responsive pedal?

 

[plastic orange]

I fitted HEL lines to my car last year, great fit, good pedal and no issues. I certainly wouldn't want to trust 20+ year old rubber on a performance car, or indeed any car.

Pete

 

[Fishy Dave]

Hi Krusty,

I fully understand what you're asking for. 'Feel' is a hard one to define and change. The biggest difference, although not one that I'd personally try, would be to replace the brake master cylinder volume/diameter. I believe a google search will net you some results, but have no recommendations or personal experience on a Corvette. I've just bought a Honda S2000 race car with aftermarket dual master cylinders (adjustable bias, non-servo) and it will be one of the first changes I make. In this case the pedal is rock solid, requires significant strength to achieve any meaningful retardation and sometimes I have to use my ears to tell if I've locked up when I've pressed too hard!

Others have given you some good advice, including the correct bleeding of the ABS pump using a Tech2. In my experience changing discs and braided hoses make fairly minor differences to feel or performance in isolation. What I believe tends to happen is that hoses and discs are typically changed at the same time as fresh fluid and pads and that it is this combination that is changing braking performance.

Given that you are visiting the ring, the number one thing I would change is the pads, both front AND rear. Ditch the OEM pads. If you opt for a higher friction material the extra retardation will change the amount of pressure you use at the pedal and therefore the feel. This is a controversial one, but I would opt for a higher friction pad that may not be road legal (EC90). I have been using race pads on the road and track with success for years on my C6 (and many other cars). The usual reaction to this is insurance validity and cold stopping. I'll take my chances on the insurance, besides once the pads have a layer of dust/rust on the back plate no-one will know and in every race pad I have used (except EBC RP1 which were terrible) they have been better from cold than a road pad. Happy to make recommendations.

Finally, I believe C5 and C6 'base' brakes are almost the same, so you have these options for improvement:
1. Fit C6 Z51 brackets and discs. These space the existing calipers further out, with larger discs. Looks nicer, fills out the space in the wheels, but limited performance/feel difference on the road.
2. Fit larger calipers and discs, either C6 Z06, Cadillac ATS-V Brembo's, or Wilwood etc. This will change the feel, given the extra pistons and fluid volume in the system.

To repeat, I would change the pads for a quality, higher friction set first of all. I know that you are not looking for more stopping power, but the pads will change the feel through the pedal too. Plus you are less likely to get fade on your first lap of the ring!

 

[Krusty]

Has anyone tried EBC YellowStuff brake pads?
They appear to be rated perfect for what I'm after... they get a great writeup for braking during normal road use, fast road use and occasional track use with no heat fade, minimal dust and even rated excellent for stopping heavy trucks.

i looked in to the others EBC offer and RedStuff gets a terrible writeup due to needing a lot of use to bed them in.
BlueStuff are not road legal here in the UK.
I have a friend who used GreenStuff on his MX5 and Subaru Impreza STI, after only 6 months and 3x 10 min track sessions at our local small Go Kart track, they are knackered! So staying away from them also.

But I would love to hear from anyone who has tried and tested YellowStuff pads on any vehicle before I throw nearly £200 at a complete set

Cheers

 

[Fishy Dave]

I've used Yellowstuff, they're 'ok' and cost effective, but don't have a lot of bite. I have raced on them in my old Caterham, but that was a 550kg car.

Given a choice I'd opt for Bluestuff NDX if you go down the EBC route. They're only not legal as they give a stronger brake performance than the 10% more than oem that is permitted. It's a daft law, but totally respect those that wish to obey it.

 

[plastic orange]

I've used Yellowstuff, they're 'ok' and cost effective, but don't have a lot of bite. I have raced on them in my old Caterham, but that was a 550kg car.

Given a choice I'd opt for Bluestuff NDX if you go down the EBC route. They're only not legal as they give a stronger brake performance than the 10% more than oem that is permitted. It's a daft law, but totally respect those that wish to obey it.

I believe they are legal going by the information on their site. I've just ordered a front set for my LS1 powered Morris Minor which has Hi spec billet 4 front brakes, so hopefully they'll be an improvement over the road version of the EBC pads supplied. When my car was built I used a willwood twin cylinder pedal box with no servo, but as has been reported it's a fair push to brake hard and I really don't want to add the complication now of a servo, but as I get older, I may have to lol.



Pete

 

[plastic orange]

I've just fitted blue ebc pads to my Minor and right away there is a noticeable improvement in cold stopping power. So much so that I'll have to alter the balance of brakes front to rear once they have completed a few miles, so a great result for not a huge outlay. I'll report how they do when I next go up the drag strip as it's full on braking once passed the finish line as there isn't a lot of run off at Crail. Top speed at the 1/4 is usually around 116 mph, so it's a good test.

Pete

 

[Yellowshark]

I have a 2001 C5 coupe. I ordered it from the factory, via the Vauxhall dealership in Brighton, in Feb 2001, it was built either late April or early May 2001 and was delivered to Brighton at end of June, I remember it was too late for Le Mans which would have been around 20/21 June. After the 3 year warranty was over, I swapped to EBC Red stuff pads (brilliant) and EBC discs (cannot remember if they are branded Red Stuff too). Again cannot remember without going to the car but whatever the label attached to the master cylinder says, that is what I use, so if It say the fluid is dot 3 that is what I use. Anyway my C5 has steel hoses not rubber. I know because the car has done 162,000 miles I have driven each and everyone of those miles. The brakes have been faultless, I do not track race but I am naughty on the road, eg I know my best mpg is gained in 6th gear at 86mph. And I had none of the supposedly problems with Red Stuff, eg getting the brakes warmed up before using them. The reduction in break dust, my reason for fitting them, was more than substantial

 

[Yellowshark]

Maybe I should add that my C5 has European A and B packs fitted