sXeVegan

I noticed in my S5 vert that after I get on the brakes really hard once, my brakes fade BADLY! I autocrossed it a few weeks ago for the first time and after a few corners each run, it kept happening. The pedal is at its normal height the whole time. I can press it as hard as i want and I'll SLOWLY slow down. I don't think i have a leak. I bled the brakes and it still happens. Should I try some new pads? Do you think its a heat issue? After a couple seconds they will be better again butthen after heavy braking it happens again. COuld my calipers be shot? Thanks for the help.

CRXtoRX7

Id try bleeding the brakes again. one of your calipers may be faulty. My friend replaced one of his rears, all the pads, and bled the system, and his brakes are fine now.

sXeVegan

thanks...

i also went from a crx to an rx7 btw...my crx was a 1st gen though. Shes forsale now.

pip

Another sxe rx7 owner? I think we are secretly breeding somewhere and no one told me ! Anyway welcome to
the forum =)

sXeVegan

bump

its not everyday you meet a fellow edger...we gotta drive cars with X's in the name though of course. Maybe a WRX will be next for me.

but anyway...anymore insight on my braking issue?

Pinfield357

what quality of brake fluid are you using? you could be boiling the fluid causing fade but that is unlikly if you just bled the system

did you bleed the system clean of all the old fluid or did you just open the bleeder screw for a pump or two to make sure that there was no air?

is your fluid dirty? try using better fluid i was using super blue fluid for about 2 yrs then this winter when i changed it i went with valvaline synthetic DOT 3&4 caue it has almost as high a boiling point a higher wet boiling point and costs less.

pull the pads and make sure they are not glazed do the same with the rotors. what kind of pad are you running? try better pads i have HAWK HPS pads now i had AXIS pads before both seem to be the same to me the AXIS are cheaper and easier to get.

just some stuff to think about

sXeVegan

im using prestone dot 4. I bled them for a whjile. I think i pretty much got all the old stuff out. Ill check the pads tomorrow night. Im not sure on the brand. I just bought the car a few months ago and they are the same ones.

WAYNE88N/A

yep, get some better pads designed for the "harder" life of x-crossing

lacycw

I think this is the same problem I had that you are having with your brakes. When I would pump them a few times, it felt like the brake booster was not getting enough vacuum, but the first few times you hit the brakes it would feel normal. After you hit the pedal a few times, the pedal would get stiff and you would have to push really hard to get it to stop which makes modulation almost impossible.

You don't really notice this on the street as you really only hit the brakes once and then drive a little before hitting them again. At an autocross, after you are on the brakes, you are wide open throttle the rest of the time. When the car is at wide open throttle, you are not drawing any vacuum so you won't build up any to make your bakes feel better the next time you brake.

What I did to correct this was to put a 'T' fitting on another large vacuum hose and connect it to the brake booster. I then just put a cap on the hard line from the original booster line going across the firewall.

I don't really know what causes the stock hose to not draw as much vacuum as it used to. I even cleaned out the banjo bolt and barb coming offof the lower intake manifold. I know this isn't really a fix to the real problem, but I just can't diagnose the problem; or the cause of it rather.

I really don't think this is a heat issue. At an autocross, you should not be able to build up enough heat to make your brakes fade, especially if you have just bled your brakes.

If anyone else has any information on this I would very much like to hear your thoughts.

- Cooper Lacy

rommellikewhoa

iTrader: (6)

yay another crx'er, i had one also hehe

1SxyRXy

arent the pads just simply getting to hot. because after a race on my car one i had to slam on the braks and i had the pedal all the way down and the brakes worked good at the begining but as they got hott they didnt work as good

sXeVegan

lacvcw- that sounds EXACTLY like my problem. Another reason i didn't think ti was heat was after 5 seconds it was fine. I didn't think heat would travel THAT fast. It would have taken longer to dissapate. Is there any vaccuum line that is better than the rest? Do you have ap ic of the line on an S5? Does anyone have ap ic of a good line to do it on with an s5? Thanks for the help!

sXeVegan

lacvcw- that sounds EXACTLY like my problem. Another reason i didn't think ti was heat was after 5 seconds it was fine. I didn't think heat would travel THAT fast. It would have taken longer to dissapate. Is there any vaccuum line that is better than the rest? Do you have ap ic of the line on an S5? Does anyone have ap ic of a good line to do it on with an s5? Thanks for the help!

CRXtoRX7

woot for the crx's. I am just prepping my 91 crx to sell right now. good luck with your brakes!

lacycw

I'll try to get a pic. tomorrow to show you what I've done. I'm not sure if the line I used was the best one... it seemed to make my idle a little unstable, which I don't see exacly why it would. It was really the only big one to use.

I just wish I knew why the regular line is no longer drawing enough vacuum.

- Cooper Lacy

lacycw

Here are the pics of what I did.

Enjoy!





- Cooper Lacy

sXeVegan

It seems to work! Thanks a lot for the help! I have amazing brakes again!

lacycw

Did you experience any problems with your idle after doing this?

- Cooper Lacy

sXeVegan

no issues with my idle yet. ITs always idled a bit on the low side but its not jumpy or anything. DO you know if that is the same vac line to do the carbcleaner or water trick with? I think i want to do that this weekend.

glorthu

Maybe your booster has a small vacuum leak... That should explain why a bigger line would make things better and why it would also roughen up your idle.

lacycw

I have tried 4 different working brake boosters, all with the same result. It is definately not a problem with the booster(s). That was my first thought when I had the problem. You can imagine how frustrated I was after trying 4 different boosters (and 3 different master cylinders). It's not so much fun after the 4th time bleeding your brakes in one week.

Keep your ideas coming though.

Thanks,
- Cooper Lacy

sXeVegan

so is this the spot for the carbon cleaner trick???

n4ji

iTrader: (1)

Maybe you shouldn't boil your brake fluid???

Michael

lacycw

I don't know anything about where to put the carb cleaner in. I personally wouldn't recommend doing that to your engine as carb cleaner is not a lubricant and will strip the walls of the rotor housings of any oil. PB Blaster would be a better choice as it is a penetrating LUBRICANT and will also break up carbon. I have had a friend use this with very good results. He however squirted it directly in through the spark plug holes and not through the manifold.

Just my $.02

- Cooper Lacy

sXeVegan

well cooper, i bought some stuff called sea foam that other people here recomended for the steam clean/carb cleaner trick. It recomended using the vac hose from your power brakes. I decided id see if there was any vac from the old stock PB line and there was a bit but not much. I poured some sea foam (found at oreilly autoparts) in the line and by the time i was done with 1/3 of the bottle, the vacuum doubled. After my autox tomorrow i will hook everything back up the stock way and let you know if its better now. It may have just been some buikldup in the line that was lowering the amount of vacuum we had.