Brake shoe break-in

Matt King
Posts: 304
Joined: December 23rd, 2008, 1:44 pm

Brake shoe break-in

Post by Matt King »

I think I glazed my new brakes shoes this weekend at my first event with the car, which lead to all sorts of problems. To avoid this in the future, can anyone suggest the proper way to break in a new set, especially given the limited track time at events? The event I'm hoping to run next weekend doesn't even have a warmup session, so I would have to bed in the brakes during a qualifying session. I'm not sure what I did wrong with the last set, but the brakes were just horrible, and I'm sure it wasn't a hydraulic or mechanical problem, plus I adjusted them a couple of times. The car just woud not slow down with anything. Granted it was my first time driving a Vee, but I can't believe the brakes would be this inadequate, so I must have scrwwed something up!
hardingfv32-1
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Re: Brake shoe break-in

Post by hardingfv32-1 »

What brand of shoes?

Brian
Matt King
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Re: Brake shoe break-in

Post by Matt King »

Stock replacement shoes. I got them from Veetech.
hardingfv32-1
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Re: Brake shoe break-in

Post by hardingfv32-1 »

Not sure what "stock " means. In general street shoes will not work. Things have never been the same since we lost asbestus. Carbotech (Mean Green) or something similar is the only type of shoe to use. They are very expensive but your competition will be using them. They also reduce brake pedal forces. Almost like power brakes, but at the expense of pad wear.

Brian
cendiv37
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Re: Brake shoe break-in

Post by cendiv37 »

Matt,

Some guys still swear by stock shoes, even some fast guys. Others don't use them anymore, at least not on the front.

I haven't used stock shoes on the front for quite a few years. I got by with them for a few years, but after using up a set in one weekend at RA, I went to the Carbotechs and basically haven't looked back. Just a Brian says, the stopping power is increased and the pedal effort is reduced, both good things in my opinion.

Lots of people can get them for you including Lybarger in McHenry IL.

Bruce

PS: You should first measure the ID of your drums. And make sure the drums are pretty good, not grooved, etc. At the very least, break the glaze in the drums before you install the shoes. The shoes seat pretty slowly and so need to fit pretty well from the get go. Also, you will need to do at least some break-in of the Carbotechs. You need to get them quite hot and then fully cooled at least once before you can rely on them.

I think there was a post here not too long ago on shoe fitting on these shoes.
Bruce
cendiv37
Speedsport
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Re: Brake shoe break-in

Post by Speedsport »

Whenever I used the "stock" shoes, I always baked them in a toaster oven for 20 minutes around 400F first. Smells bad, but keeps the shoes from glazing over. You can try to save the ones you have by using some rough sand paper, sanding all the top layer off the shoes, and roughing up the drums a bit.


The toaster will not work on the Carbotechs.
Matt King
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Joined: December 23rd, 2008, 1:44 pm

Re: Brake shoe break-in

Post by Matt King »

Thanks for the tips. I'm going to try the sand paper route and see if I can salvage these pads. I'd like to have some confidence that I am getting the stock pads working properly before I jump to the Carbotechs. I assume these are a carbon/metallic compound that needs to be bedded in to form a transfer layer on the drum surface?
hardingfv32-1
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Re: Brake shoe break-in

Post by hardingfv32-1 »

Michael

What type of brake shoe will you be pressing on when you pull out from the draft and brake for turn 5 at Road America? Having driven most of the great tracks in the US, This is the only break zone where I have experienced brake fade. That was before Carbotech, but it was very impressive.

Brian
fv31
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Joined: July 3rd, 2006, 7:38 pm

Re: Brake shoe break-in

Post by fv31 »

i've had students come to driver school complaining that the car "won't stop"......only to find out they're running stock front shoes. their astonishment when they put a set of carbotechs on is very common. at a heavy braking track like kershaw, you'll destroy a set in no time. and they won't stop worth a damn. i've actually said to people that "stock shoes are great....for one corner."

spend the money and get the carbotechs. as was said before, your competition will be using them....and the more comfortable you are in the car, the faster you'll go.

as for the rears, i've ran both. rear wear is negligible. i seem to lose a seal and oil them up before i've ever worn them out. come to think of it, i've never worn a set of rears out.....but i've thrown plenty away due to getting oil on them. i really don't see a difference in the rears (except for cost) so i run stock there.

bill
fv31
Speedsport
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Re: Brake shoe break-in

Post by Speedsport »

Brian,

I use Carbotech brakes, and agree they are fantastic. My point was if you are going to use the stock shoes, some time in the toaster oven before using them makes a HUGE difference. I raced for a long time at Road America going into turn 5 on stock shoes without a problem. Considering the original poster made no comment about his budget, I can't assume someone starting out would want to spend the money for Carbotech brakes yet. Yes they are worth the money, but for someone in their first season?

Michael Varacins
Matt King
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Re: Brake shoe break-in

Post by Matt King »

What kind of shoe life do you get out of the Carbotechs? Anybody know which if Carbotech's compounds they use? I have used their XP10s on my Mustang, so I'm famililar with the characteristics of that compound. I liked them, but they didn't give good pad life so I switched to Hawks. I wish Hawk made FV shoes, since they sponsored me last year when I raced the Mustang!
brian
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Re: Brake shoe break-in

Post by brian »

I usally manage quite a few weekends on Carbotechs but I do rotate them EVERY weekend. Try finding a local brake relining shop in your area and ask for either heavy duty fork lift material or elevator brake material. You'll pay much less than Carbotechs. They will be nearly as good but require a bit more pedal pressure. Life expendency is much better than Carbo's too. Whatever you do, do not mention the R word to the brake shop. If you tell them it's for racing, they'll freak and may refuse to reline your shoes. Tell them it's for downhills in a dune buggy.
The above post is for reference only and your results may vary. This post is not intended to reflect the views or opinions of SCCA and should not be considered an analysis or opinion of the rules written in the GCR.
Matt King
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Re: Brake shoe break-in

Post by Matt King »

Does anyone have any experience using KFP carbon kevlar shoes on a FV?
jstoezel
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Re: Brake shoe break-in

Post by jstoezel »

What does the heat treatment do to the shoe-aramid? I've got a temperature controlled oven that can be setup for different heat ramps and cycles. I wonder if a standard shoe could be improved by controlling the heat ramp and the number of cycles it goes through.

Speedsport wrote:Whenever I used the "stock" shoes, I always baked them in a toaster oven for 20 minutes around 400F first. Smells bad, but keeps the shoes from glazing over. You can try to save the ones you have by using some rough sand paper, sanding all the top layer off the shoes, and roughing up the drums a bit.


The toaster will not work on the Carbotechs.
Jean-Sebastien Stoezel
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SR Racing
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Re: Brake shoe break-in

Post by SR Racing »

I think there may be some radically different opinions on this. We sell the Carbotechs, but I think we sell the stock shoes 5:1 over them. But I know lots of people swear by them. Greg Schings ran them a couple times and didn't like them much. Since then he always ran the stock ones. When the CT's are 6+ times the price and don't last as long, you might want to make a carefull comparison. I really think carefull setup is more important.

While the CT's are probably better under careful scrutiny, IF you are having trouble stopping a Vee with the stock brakes SOMETHING ELSE is wrong. Also, unless your drums and shoes are dragging, true brake "fade" in a vee is pretty unlikely. (Definition being that the shoe is so hot that it is gassing and causing the shoe to "float" on the drum.) I experienced it only one time (Blackhawk) and that was due to some brake dragging.

I typically recommend to my customers to use stock shoes until they get to that point where braking is the only thing that is keeping them off the podium. Then upgrade and see if it makes a difference. IMO
smsazzy
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Re: Brake shoe break-in

Post by smsazzy »

When I was first starting out, I used a front shoe type I got from Jess Jeitman in Portland, OR. It was not a stock compound, but was similarly priced. It was kind of an intermediate step between the two. I used stock rears in the back for quite a while.

I went to the Carbotech brakes when I started running nationals. I rotate them top to bottom to extend their life and even the wear, I get about 6-9 race weekends out of them. (1 season of nationals) Maybe I am too easy on my brakes. :-)

I would recommend buying the Carbotechs as well, but feel free to sort the car and get used to it with stock shoes.

One word of caution, I would highly recommend to get any impressions you developed of braking from driving a Mustang out of your head. You're comparing stopping a nearly 4000 pound car with power brakes. You are now in an 825-850 pound car with non-powered DRUM brakes.

Just keep your brakes adjusted and bleed them properly and you'll adjust.
Stephen Saslow
FV 09 NWR
Matt King
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Re: Brake shoe break-in

Post by Matt King »

Two full race seasons have passed since I started this thread. Any illusions about braking performance have long since passed. Brakes are working fine and I've been using Carbotech shoes for a year. ;)
jstoezel
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Joined: September 19th, 2010, 6:21 pm

Re: Brake shoe break-in

Post by jstoezel »

All over last season it felt like I had no brakes. I had re-plumbered the whole system over the winter with hard lines, I had replaced both master cylinders with brand new ones, and had also replaced the front slave cylinders.

I bleed my brake system every morning of a race day. The week before a race week-end I also deglaze the drums. I adjust the brakes almost every time before I go on the track

The pedal seems a bit long, to limit pedal travel I have to get the shoes to drag a bit. I can still turn the wheels by hand, and they turn by themselves once launched. You hear the shoes dragging.

Even when I push really hard on the pedal I hardly ever lock up the wheels in the dry (if ever), except in the rain. I was told it's a Vee and it has no brakes, but I see other cars locking their tires.

I noticed the front brake shoes were developing hair line cracks over their length. Eventually the crack got quite big and I replaced the shoes with new stock one.

So yes braking is an issue for me. I wonder if my drums are worn, and I have to compensate by dragging the shoes. By dragging the shoes they overheat and develop hair line cracks...

How do you check your drums?
My original question was about cycling shoes. Do you need to go through cycles, or is a single 400F bake good enough, as suggested?

Thanks,
JS



SR Racing wrote:I think there may be some radically different opinions on this. We sell the Carbotechs, but I think we sell the stock shoes 5:1 over them. But I know lots of people swear by them. Greg Schings ran them a couple times and didn't like them much. Since then he always ran the stock ones. When the CT's are 6+ times the price and don't last as long, you might want to make a carefull comparison. I really think carefull setup is more important.

While the CT's are probably better under careful scrutiny, IF you are having trouble stopping a Vee with the stock brakes SOMETHING ELSE is wrong. Also, unless your drums and shoes are dragging, true brake "fade" in a vee is pretty unlikely. (Definition being that the shoe is so hot that it is gassing and causing the shoe to "float" on the drum.) I experienced it only one time (Blackhawk) and that was due to some brake dragging.

I typically recommend to my customers to use stock shoes until they get to that point where braking is the only thing that is keeping them off the podium. Then upgrade and see if it makes a difference. IMO
Last edited by jstoezel on December 6th, 2010, 2:39 pm, edited 1 time in total.
Jean-Sebastien Stoezel
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Dietmar
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Re: Brake shoe break-in

Post by Dietmar »

JS:

If I read this correctly, you can not get the brakes to lock no matter how hard you apply the brakes-except in the rain.
I would venture to say that your bias is off to the rear.

Simple check- jack up the car, support it on jack stands on all 4 corners. Have someone apply steady pressure to the brakes ( gently at first) until the fronts lock up. When you can no longer turn the front wheel, the rears should still be able to turn- with drag.

You should NOT put any drag on the shoes when cold, and there should not be any need to bleed the brakes more than once a year- unless there is a leak or you have changed a cylinder.

If you need more info, feel free to call.

Hope this helps

Dietmar
http://www.quixoteracing.com
hardingfv32-1
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Re: Brake shoe break-in

Post by hardingfv32-1 »

1) There is a good chance the leverage setting of your brake pedal is wrong. What is your pedal movement measurement? Your definition of long might be incorrect for a FV. You should be able to lock up the brakes in the dry with any shoe. Note, the expensive shoes require less pedal pressure.

2) All stock shoes are not the same. Most will crack as you have stated. You have to zero in on the one or two lining materials that will not crack. Even when you find something, availability can change over the years. A lot of us find the expensive shoes a lot less trouble.

Brian
jstoezel
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Re: Brake shoe break-in

Post by jstoezel »

Thanks for the detailed answer, that may be the issue. I won't be able to check that until spring though, my car is stored in an uninsulated/unheated garage and temperatures will remain below 15F for a little while.

It's interesting what you say about not bleeding the brakes for the season. When I raced go-karts I would bleed the brakes once a season too, but somehow I've seen FV racers bleed their brakes pretty much every morning of a race...

The pedal rack that came with the car is custom made, with a balance bar and a remote adjuster. Something I've noticed is that even when the remote bias control is all the way to the rear, there seems to be a great amount of pressure applied to the front slave cylinders: the balance bar does not remain perpendicular to the travel of the pedal when the brakes are applied, and tends to favor the front cylinders.
Dietmar wrote:JS:

If I read this correctly, you can not get the brakes to lock no matter how hard you apply the brakes-except in the rain.
I would venture to say that your bias is off to the rear.

Simple check- jack up the car, support it on jack stands on all 4 corners. Have someone apply steady pressure to the brakes ( gently at first) until the fronts lock up. When you can no longer turn the front wheel, the rears should still be able to turn- with drag.

You should NOT put any drag on the shoes when cold, and there should not be any need to bleed the brakes more than once a year- unless there is a leak or you have changed a cylinder.

If you need more info, feel free to call.

Hope this helps

Dietmar
http://www.quixoteracing.com
Jean-Sebastien Stoezel
WCMA FV #0
jstoezel
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Re: Brake shoe break-in

Post by jstoezel »

hardingfv32-1 wrote:1) There is a good chance the leverage setting of your brake pedal is wrong. What is your pedal movement measurement? Your definition of long might be incorrect for a FV. You should be able to lock up the brakes in the dry with any shoe. Note, the expensive shoes require less pedal pressure.
I don't have the pedal in front of me but for say a 9" pedal, the top of the pedal would travel between 2" and 2" 1/2. Again this is approximated from what it felt like at the track. I won't be able to check for sure until spring comes.
hardingfv32-1 wrote: 2) All stock shoes are not the same. Most will crack as you have stated. You have to zero in on the one or two lining materials that will not crack. Even when you find something, availability can change over the years. A lot of us find the expensive shoes a lot less trouble.

Brian

I read earlier (either in this post or another one) that they are 2 compounds and/or 2 sizes.
http://www.ctbrakes.com/pads.asp?Make=V ... er_Beelte)
I'm assuming the part numbers to be used for a vee are CTS269 and CTS270
Which compound do you use, 912 or 913? Do you need the extra braking power that comes with the 913?
Jean-Sebastien Stoezel
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tiagosantos
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Re: Brake shoe break-in

Post by tiagosantos »

I had the same problem (hitting the brakes as hard as I could and not slowing down all that much - front wheels weren't locking up no matter what) on my last race weekend - after messing around with the brake pedal and getting the balance bar setup wrong. My plan is to do exactly what Dietmar recommended - except I'll be using someone else's tip of using a ratchet strap on the brake pedal instead of a helper. I couldn't keep my wife's attention on the brake pedal for more than 10 seconds :lol:

I'm not sure that I can fix it yet (confident that I can!) but at least I know how good the brakes can feel, from driving another Vee with brakes set up by someone who knew what he was doing! I think the reputation Vees have for bad brakes is not well deserved. They can be a pain to make work (if you're a noob like me) but when they work, they work great!
FV80
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Re: Brake shoe break-in

Post by FV80 »

One thing I learned SOME TIME ago :-) is that the pedal arrangement should be set up such that the pedal NEVER travels 'overcenter' - that is.. the pedal should go VERTICAL at the most critical, most pedal depression, most HARD you can press it under ANY circumstances --- NEVER go past vertical. If you go overcenter, you loose an unbelievable amount of pressure that you can apply to the master cylinders.
ALWAYS set up your pedal assembly such that you (should) never pass vertical..

I was truly astounded at how MUCH DIFFERENCE THAT MADE in my car.

Steve, FV80
The Racer's Wedge and now a Vortech, FV80
hardingfv32-1
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Re: Brake shoe break-in

Post by hardingfv32-1 »

Or... You can set things up so the pedal is vertical (leverage at its highest when you first hit the brakes and just taking up the shoe to drum clearance) and goes to a less leveraged position the more you press the pedal.

Basically you have a heavy/high leverage/fast pedal when you are taking up the shoe to drum clearance and a lighter/low leverage/slower pedal when you need maximum brake pressure. You will not notice the first high leverage part of the braking action because the shoes are not yet applying pressure to the drum.

Brian
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