|
Replaced brake fluid
I just replaced the brake fluid on my 2008 Backdraft #648. It has 12,500 miles on it and had Dot 5 fluid in it. I replaced it with Dot 3 - 4 fluid. The original fluid was dirty and had some "gel" in it. I found out that when filling the reservoir, if the fluid is a little low, approx. 1 oz, the red warning light comes on. I also discovered that on the dual reservoir, the front chamber is for the rear brakes and the rear chamber is for the front brakes...go figure. Hope this will help someone.
|
What's required to convert a brake system to DOT 3/4? Flush with alcohol ? Replace seals?
|
Quote:
|
I used a vacuum bleeding system to remove the original fluid and flushed about a quart of Dot 3 - 4 through the system until the fluid was clear. It's been a couple of hundred miles with no problems.
|
Converting from Dot 5 which is silicone based to Dot 3 or 4 can be a real problem. I don't know who installed the Dot 5 in the car to start with. The system must be clear of any sign of the Dot 5 prior to installing the dot 3-4. Same thing must be going the other way. The two fluids don't mix.
|
Quote:
Among the issues are that seals suitable for silicone are thought to be incompatable with DOT 3,4 systems. |
The DOT 5 in the Backdrafts was abandoned a very long time ago. Was your fluid purple? That was the way to tell back then.
|
That could be a problem. When you mix the two, they clot. Not a good thing in a hydraulic system.
I keep hearing that seal material can be incompatible, too. But have never seen that companies sell different seals depending on the fluid used. Ideally, you should completly disassemble the system and clean it out. Rebuild the MC's and all the calipers. Flush the heck out of the lines to prevent clots. |
How can we tell what fluid it has? Mine is purpule? So, is this DOT 3,4,or 5?
|
I believe Jay posted above that purple indicates five.
|
I used DOT 5 in a C3 Corvette many years ago when I did a complete overhaul of the brake system, and it was indeed purple. Thinking that’s done so one can tell the difference… but can’t say for sure, as that was the only time I used it.
|
Just watched an episode of hand built hot rods on motortrend and this was exactly the issue they ran into. Older Custom Corvette with a mushy brake pedal. Brake fluid with pink because the two were mixed. They wound up replacing the calipers after flushing out the brake lines with gallons of clean fluid. I do remember my old 66 Vette using silicone brake fluid. They reiterated that mixing the two was a big No-No.
Fred |
The way I checked mine was mixing some fluid with a little water in a container and shaking it up and then letting it settle out. Dot 5 is silicone based so will not stay mixed. Dot 3 and Dot 4 should stay mixed with the water.
I am no expert, just what my research found. |
Dot 5?
Quote:
|
Water / condensaion--------- mixed with brake fluid lowers the boiling temp of the fluid-so some that is good for say 500 degrees is lowered to 350*? of worse----------the military back many decades ago had problems of water in brake fluids and speced the Dot 5 because of the vehicles stored in strateit? places arond the world--------However for performance type vehicles there are some extremely hot areas around the differant portions of the braking/clutch systems-------and Dot 5, which won't mix with water,well, the water boils at 212* and of course your brake/hydraulic clutch system is burnt toast-----------its better to have a milky substance that boils at 500* than something with water in it that boils at 212* when you need to stop------or slow down -------Happened to me in the command vehicle of a very long military convoy on a pretty sharp downhill curve ----------but I haddened had any signs of trouble after submerging the M151 in that stream the day before---------
|
Quote:
|
I guess I should just leave it alone.
I have been following this because like many older Backdrafts, I have DOT 3/4 for the clutch and DOT 5 for the brakes. I have no issues with my brakes so am I correct in assuming I should just leave it or am I looking at issues down the road with the DOT 5. Thanks
Fred |
Hi Guys, First time poster here! I run my Hi-Tech with Dot 5 for the brakes and Dot 3 for the clutch only.
|
Quote:
DoT 5 is not recommended for 2 reasons. First, it's compressible. That means you'll get a little bit of a mushy pedal. Not much you can do about that. Second, it's hydrophobic. Any water that gets in the system will not mix with the fluid, leaving small puddles and reservoirs of water in the system. Any metal components exposed to water will oxidize. When water gets into the calipers, it will turn to steam at relatively low temps. That's bad. The easy way to prevent that is to completely flush the system with new fluid as a routine maintenance step. As you flush, take a close look at the fluid. If it has tiny particles in it, something ion there is rusting and heading for failure. You'll have to take the whole system apart to find it all. |
Thanks Bob.
As it turns out I don't have DOT after all, It just looked purple through the opaque reservoir. Thanks for the input. Fred |
| All times are GMT -7. The time now is 06:28 PM. |
Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: