That is a possibility it looks awful yellow, most D.O.T. I have bought has been purple. here is a link to a thread on how to test it.
Brake fluid -how to tell which kind you have DOT 3 or DOT 5
Katavic918 - These take dot5 fluid btw, I wonder if they mixed some dot 3 in there?
TM 9-2320-280-20-2 page 7-22 clearly calls for "silicon based brake fluid". Sounds like DOT 5 to me.
DOT 5 is silicone based brake fluid, is less common and does not scavenge for water the same way as DOT 3, 4, or 5.1. DOT 3 and 4 are more common, are glycol based, and scavenge for water by absorbing it IIRC. They do this to prevent rust in the system.
Mixing glycol based with silicon based fluid can lead to "catastrophic failure", according to some manuals and the Internet (and the Internet never lies - LOL).
I agree with the others in this thread and I also suggest you purge the entire system if there is any question about incorrect fluid or bad fluid. You don't just need to change the fluid, you need to purge or wash out the system. Drain it, fill it, bleed it, pump it a bunch of times, and then pump and bleed again to remove residue of DOT3/4. Bleeding alone will leave residue and might leave contaminated stuff in the caliper cylinders.
I change brake fluid every 2 years on my vehicles. I drive aggressively at times, due to NYC stop and go traffic, so between living near water and heating up the fluid, I find clear brake fluid has turned yellow or brown at 2 years, so it is potentially less effective at braking and water absorption. In all honesty though, this is my first DOT 5 vehicle IIRC.
My question is... Is there a water separator in the HMMWV in the brake system that removes water given that DOT 5 is silicon based/hydrophobic?
T
