Boiled the brakes, fronts faded bad (not rx7)

Whizbang · 07-10-2010, 11:15 PM

so i acquired a 1980 toyota celica that i am using as my rallycross car and eventually my rally car while i build the rx7 (so i can learn on this slow car and build the rx7 correctly).

anyway, been doing some seat time in this car and found the brakes to boil pretty bad. Didnt think you could actually HEAR it boil either...

but i digress, the fronts faded bad, the rears not as much and it became rather unstable if you had to use the brakes for any reason.

So what is a good cure for this? Im going to flush the brakes and replace with the best fluid i can find. But is this enough? Or should i look to whats available for larger brakes? Im sure some other toyota model has something a tad larger.

Kentetsu · 07-11-2010, 03:26 AM

Duct some air to those badboys and let 'em breathe man!

Maybe some decent pads too. But if that doesn't do it, you'll probably have to go with larger discs to help dissipate the heat.

Any chance that the original fluid was in shitty condition? Maybe water contaminated?

.

RETed · 07-11-2010, 05:08 AM

Cheapest and easiest "fix" would be to run better brake fluid...

If it's not enough, then go with ducting...

Almost anything else is EXPENSIVE.

-Ted

Whizbang · 07-11-2010, 12:24 PM

im going to flush and replace the brake fluid and see how that pans out.

Tinman · 07-11-2010, 01:24 PM

Try the simple stuff first. Fresh fluid is a must but also look to see if the caliper slides are working smoothly and not binding in anyway that could cause the pads to drag after the pedal is released. Make sure the lines and hoses are in good condition and not kinked or collapsed. I have seen situations where the pressure in the caliper could not be released due to a faulty line or collapsed hose causing severe drag. A maladjusted master cylinder pushrod can cause the same problem.

If everything in the hydraulic system is in perfect working condition the best thing to do to reduce heat is pad choice and or driving style.

josh18_2k · 07-11-2010, 10:41 PM

if the pedal went to the floor, its the fluid.
if the pedal stayed hard(ish), but the car wasnt slowing down, thats the pads.

Whizbang · 07-11-2010, 11:16 PM

the pedal stayed pretty decent but the fluid was certainly boiling. I heard it and saw it and it was damn hot coming out of the top of the master cylinder. Im going to flush the fluid and inspect the brakes a bit.

Kentetsu · 07-12-2010, 10:05 AM

You might also (not sure) want to take a look at your braking method.

Good firm braking applied when needed = cooler rotors
Less pressure applied for longer periods = overheated rotors

07-10-2010, 11:15 PM	#1
Whizbang Respecognize! Join Date: Jul 2008 Location: Δx = ħ/2Δp iTrader: (5) Posts: 3,190 Rep Power: 20	Boiled the brakes, fronts faded bad (not rx7) so i acquired a 1980 toyota celica that i am using as my rallycross car and eventually my rally car while i build the rx7 (so i can learn on this slow car and build the rx7 correctly). anyway, been doing some seat time in this car and found the brakes to boil pretty bad. Didnt think you could actually HEAR it boil either... but i digress, the fronts faded bad, the rears not as much and it became rather unstable if you had to use the brakes for any reason. So what is a good cure for this? Im going to flush the brakes and replace with the best fluid i can find. But is this enough? Or should i look to whats available for larger brakes? Im sure some other toyota model has something a tad larger. __________________ For current updates and event coverage check out Follow on Twitter! @WhizbangRally Whizbang Rally's Webpage \| Facebook

07-11-2010, 03:26 AM	#2
Kentetsu RCC Contributor Join Date: Feb 2008 Location: Grand Rapids, Michigan iTrader: (1) Posts: 530 Rep Power: 17	Duct some air to those badboys and let 'em breathe man! Maybe some decent pads too. But if that doesn't do it, you'll probably have to go with larger discs to help dissipate the heat. Any chance that the original fluid was in shitty condition? Maybe water contaminated? . __________________ "Learn from the past, or it will become your future...." '85 GS 12a + LSD/Sterling carb/Respeed coilovers/Respeed front swaybar/Respeed adj. rear spring perches/Illuminas/Bilsteins on rear AutoX vids @ http://www.youtube.com/user/Kentetsu1

07-11-2010, 12:24 PM	#4
Whizbang Respecognize! Join Date: Jul 2008 Location: Δx = ħ/2Δp iTrader: (5) Posts: 3,190 Rep Power: 20	im going to flush and replace the brake fluid and see how that pans out. __________________ For current updates and event coverage check out Follow on Twitter! @WhizbangRally Whizbang Rally's Webpage \| Facebook

07-11-2010, 10:41 PM	#6
josh18_2k Rotary Fanatic Join Date: Feb 2008 Location: Gresham, OR iTrader: (0) Posts: 473 Rep Power: 17	if the pedal went to the floor, its the fluid. if the pedal stayed hard(ish), but the car wasnt slowing down, thats the pads. __________________

07-11-2010, 11:16 PM	#7
Whizbang Respecognize! Join Date: Jul 2008 Location: Δx = ħ/2Δp iTrader: (5) Posts: 3,190 Rep Power: 20	the pedal stayed pretty decent but the fluid was certainly boiling. I heard it and saw it and it was damn hot coming out of the top of the master cylinder. Im going to flush the fluid and inspect the brakes a bit. __________________ For current updates and event coverage check out Follow on Twitter! @WhizbangRally Whizbang Rally's Webpage \| Facebook

07-11-2010, 01:24 PM	#5
Tinman Rotary Fan in Training Join Date: Feb 2008 Location: Central Ohio iTrader: (0) Posts: 36 Rep Power: 0	Try the simple stuff first. Fresh fluid is a must but also look to see if the caliper slides are working smoothly and not binding in anyway that could cause the pads to drag after the pedal is released. Make sure the lines and hoses are in good condition and not kinked or collapsed. I have seen situations where the pressure in the caliper could not be released due to a faulty line or collapsed hose causing severe drag. A maladjusted master cylinder pushrod can cause the same problem. If everything in the hydraulic system is in perfect working condition the best thing to do to reduce heat is pad choice and or driving style.

07-12-2010, 10:05 AM	#8
Kentetsu RCC Contributor Join Date: Feb 2008 Location: Grand Rapids, Michigan iTrader: (1) Posts: 530 Rep Power: 17	You might also (not sure) want to take a look at your braking method. Good firm braking applied when needed = cooler rotors Less pressure applied for longer periods = overheated rotors