Brake Fluid
Thread Starter
TECH Regular
Joined: Dec 2005
Posts: 408
Likes: 0
From: Mechanicsville, Va
Brake Fluid I have a quick question, I just got back from vir doing hpde and my brakes didnt fair to well. Iam getting hawk hp+ pads but I also need to change my fluid. I flushed the system out before the event and put in dot 4 fluid. My instructor told me that I could run dot 5 fluid in my stock system. Can the system hold that fluid, I didnt know if the seals would hold it. Any advice would be great.
-Thanks Brandon
-Thanks Brandon
Launching!
Joined: Nov 2006
Posts: 232
Likes: 0
From: Seven Nation Army
i wouldnt mix dot 4 and dot 5.... i run motul 5.1
Not to be confused with DOT 5.1, a polyethylene glycol based fluid.
DOT 5 is one of several designations of brake fluid denoting a particular mixture of chemicals imparting specified ranges of boiling point.
DOT 5 is a silicone based brake fluid. It is not compatible with any polyethylene glycol based fluids.
Not to be confused with DOT 5.1, a polyethylene glycol based fluid.
DOT 5 is one of several designations of brake fluid denoting a particular mixture of chemicals imparting specified ranges of boiling point.
DOT 5 is a silicone based brake fluid. It is not compatible with any polyethylene glycol based fluids.
Copy & Paste Moderator
Joined: Apr 2002
Posts: 9,764
Likes: 208
From: Eastern MA
Here is a "white paper" on brake fluid:
http://www.stoptech.com/tech_info/wp...fluid_1a.shtml
Like 98ws61le said, DOT 5 brake fluid is not compatible with any other brake fluid. For starters, its Silicone-based which is different from all the other brake fluids and microscopic air bubbles can can get trapped between the silicone molecules.
If you read the white paper, you'll get plenty more information on the subject and see why DOT5 shouldn't be used.
BTW, that "white paper" is in the Brake FAQ Sticky:
https://ls1tech.com/forums/suspension-brakes/353903-brake-faq.html
Here are some more white papers from that site:
http://www.stoptech.com/tech_info/te...e_papers.shtml
http://www.stoptech.com/tech_info/wp...fluid_1a.shtml
Like 98ws61le said, DOT 5 brake fluid is not compatible with any other brake fluid. For starters, its Silicone-based which is different from all the other brake fluids and microscopic air bubbles can can get trapped between the silicone molecules.
If you read the white paper, you'll get plenty more information on the subject and see why DOT5 shouldn't be used.
BTW, that "white paper" is in the Brake FAQ Sticky:
https://ls1tech.com/forums/suspension-brakes/353903-brake-faq.html
Here are some more white papers from that site:
http://www.stoptech.com/tech_info/te...e_papers.shtml
Last edited by VIP1; Apr 2, 2007 at 01:41 PM.
Thread Starter
TECH Regular
Joined: Dec 2005
Posts: 408
Likes: 0
From: Mechanicsville, Va
Thanks for the replys I wasnt planning on mixing the two different fluids. I might flush my system again and put in some dot4 fluid again. I think most of my braking problems were from my oem pads not my fluid. Would you suggest running dot 4 fluids, its my daily driver and will be seeing some track days and hpde.
TECH Resident
Joined: Jul 2006
Posts: 828
Likes: 0
From: North Dallas
Yes, run DOT4 fluid for it's higher boiling point. IMO, you are on the right track with the pads though. I assume that you experienced brake fade. I've done 3 HPDEs now with DOT4 fluid, ceramic pads, and power slot rotors. Everything else brakewise is stock and I have been very impressed. No fade at all. I don't think that the slotted rotors made much difference but the pads definitely did. OEM brakes can be down right scary when they get hot!
Also, when you come off the track, don't leave your foot on the brakes for very long and don't set the e-brake until they cool off. This is to help keep the rotors from warping.
Also, when you come off the track, don't leave your foot on the brakes for very long and don't set the e-brake until they cool off. This is to help keep the rotors from warping.
Thread Starter
TECH Regular
Joined: Dec 2005
Posts: 408
Likes: 0
From: Mechanicsville, Va
Originally Posted by Arctic2002ss
Yes, run DOT4 fluid for it's higher boiling point. IMO, you are on the right track with the pads though. I assume that you experienced brake fade. I've done 3 HPDEs now with DOT4 fluid, ceramic pads, and power slot rotors. Everything else brakewise is stock and I have been very impressed. No fade at all. I don't think that the slotted rotors made much difference but the pads definitely did. OEM brakes can be down right scary when they get hot!
Also, when you come off the track, don't leave your foot on the brakes for very long and don't set the e-brake until they cool off. This is to help keep the rotors from warping.
Also, when you come off the track, don't leave your foot on the brakes for very long and don't set the e-brake until they cool off. This is to help keep the rotors from warping.
TECH Resident
Joined: Jul 2006
Posts: 828
Likes: 0
From: North Dallas
Originally Posted by lt1_man
Yeah when I came in I left it in gear and tired using as little brakes as possible. I will flush out the system and run dot 4 fluid. What pads are you running I have only heard about hawk hp+ pads but I didnt know if there was anything else out there. Also I was in hpde phase 1 for the first time and I loved it.
Yes, these events are a blast. I think anybody with a fast car should do one of them.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Thread Starter
TECH Regular
Joined: Dec 2005
Posts: 408
Likes: 0
From: Mechanicsville, Va
Yeah I thought about that but I want to keep my brakes stock, caliper wise, so I can stay in the same class in autocross because I dont have the money to move up in the next class. lol
After my first time at Road Atlanta, I had to upgrade my brakes. Changed the fluid and got some Hawk racing pads from Sam for the fronts. When I went back with the new set-up, even though I was using the brakes 5 times as much, it was almost the end of the 30 min session before they would start to fade. Worked extremely well. The front racing pads were a little expensive, like $200 for the fronts, but well worth it. On the backstretch at RA, you go from 135 mph downhill into a 90 degree left hand turn. VERY hard on brakes.
BTW, how did you get on VIR? I am only 3 hrs away. It looks like a cool track. Love doing the track days.
BTW, how did you get on VIR? I am only 3 hrs away. It looks like a cool track. Love doing the track days.