lt1_man

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

98ws61le

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.

VIP1

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

lt1_man

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.

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.

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.

Arctic2002ss

There is a machine shop here that sells DURA ceramic pads. Nobody has ever heard of them, lol, but they work. I think they are a generic version of something but I'm not sure what.

Yes, these events are a blast. I think anybody with a fast car should do one of them.

lt1_man

Ok I will look into that. Here is a few pictures from the event.

JimboManJones

Get ls1 brakes, you can find whole sets(spindles and all) on ebay for like 150-200, get new pads and rotors, and you'll be doing alot better, the lt1 brakes still suck even with upgraded pads...

lt1_man

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

WADDISME

iTrader: (4)

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.