After learning that Ford Heavy Duty DOT 3 brake fluid (part # c6az-19542-aa/ab) is no longer available, I have been searching for replacement brake fluid. The Heavy Duty fluid was fantastic stuff for the cost, and the replacement fluids from Ford have lower boiling points.


Anybody know the reason for the change? Perhaps better corrosion resistance?


I want to find the best fluid for the cost, but don't want to pay $15.00+/ 12 oz., keeping in mind towing a 7,000 lb. 32 foot travel trailer down long mountain grades.


The truck is a 2001 F250 Super Duty SRW 4x4.


I am attracted to DOT 4 fluids because of their higher boiling points but have found some information indicating that DOT 4 fluid typically has a higher viscosity which can affect the performance of the ABS system at low temperatures. I regularly drive my truck in Wyoming winters where the temps can slide below -30 degrees F. (and are usually accompanied by icy roads when they do.) Obviously, I want to maintain optimum ABS performance!


Anybody have any experience with DOT 4 fluids in our trucks in this kind of cold weather?


Thanks!

 

DOT type 4 brake fluid is pretty much in all ways superior to DOT type 3. That said, you also pay the price for the better fluid, and it truly doesn't last any longer. It just has the higher boil temp, and better viscosity. Most high-end Euro cars and any aftermarket heavy braking systems call for the higher temp DOT type 4. They are also not really interchangeable. In a pinch you can add DOT 4 to a DOT 3 system, but you cannot ever do the reverse (well shouldn't).

I have not looked yet as to what is in my truck, but I see in the manual they do call for either type to be used, so it appears the switch is possible. I have used ATE SuperBlue and SuperGold DOT 4 fluid previously in both MINIs and Volvos. It's great stuff, and best off by alternating the color you can easily change the fluids out.

And that's the next challenge, if your current system is DOT 3, you want to make sure you get all of it out, it wouldn't be necessary to clean the system, but just that the old stuff is out. That usually means putting all 4 tires up in the air, and your right rear tire the highest. Then use a pressured brake fluid tank or pump to push the old fluid out that rear tire. Again, using a different colored DOT 4 for the add (like ATE SuperBlue) makes it easy as you can see when it starts drawing the new color thru you know you have purged that line. Then repeat with the other 3.

It's a project for sure, but if you are concerned about boil temps and overall hold up of the fluid under all sorts of crazy temps, it might be something to consider.

Edit: Sorry it's been a few years since I have done a break fluid swap... and in the US you can no longer buy brake tinted fluid.... darnit. The stopped selling it in early 2013. So it does make the swap a little trickier, but can still be done.

 

I did come across the prohibition of blue brake fluid in the U.S. Seems the DOT wants brake fluid in this country to be clear or amber, to differentiate it from "other automotive fluids" (which, other than red power steering and ATF fluids) are all pretty much clear or amber! Guvmut burro-crazy at its finest!!




My owner's manual and my workshop manual both spec DOT 3 for my truck. Anybody know when Ford went to the dual listing? Were there changes made to the ABS system (or the fluids) to accommodate DOT 4? Hoping a brake systems engineer can weigh in here....

 

Ford sells the PM-1-C DOT 3 fluid. It is still in use in the Super Duty trucks

Motorcraft® Brake & Engine Performance Fluid & Cleaners ? The Official Ford Parts Site | FordParts.com

 

Check out amsoil brake fluid, if you are a preferred member you can get dot 4 for $10.80 or dot 3 for $5.70