I cannot find info on Dexter's nor trailer parts suppliers websites about compatible brake fluids for the disc brake model. I've been using DOT 3 but the old fluid in the MC tested off the charts for water content. Opened two sealed DOT 3 bottles I had on hand and same thing! Bought a new bottle 2 days ago removed and replaced the fluid in the MC, and today tested off the charts for water as did the remainder in the bottle! Opened a used bottle of 3-4 year old Castrol $RF DOT 4 and 0% water!!! Is DOT 4 compatible?

What brand brake fluid is everyone having success with? Prestone is one sealed container I opened and it was full of water. I find it hard to believe I need to put $75/bottle brake fluid in a trailer for it not to attract water from the atmosphere in a sealed MC.

Thanks for any insight you can lend.

Dot 3 and 4 are compatible with each other.

Been running valvaline for years in everything I own. Never tested it but never had any issues.

Not even sure HOW a sealed container can get water absorption...suspect your testing is flawed.

Explain how dipping a electronic tester in a fluid sample is flawed, especially considering the 3 year old open container sample tested at 0% as detailed in post #1. I say the products (like many today) are flawed, or are you of the opinion that everything you're sold new is on the up and up?

I test all brake fluid I buy (now you see why) before using it and at least once a year in every braking system I own. If not at best you'll have diminished braking performance and at worst you'll rust out metal brake system components from the inside out, which can result in a catastrophic braking failure. The only reason for replacing brake fluid is due to water content, no reason to replace it at 4 years per a vehicle owners manual if it tests good. That number is simply in the manual as an estimate of when water will be absorbed into the fluid under normal usage conditions.

I disagree. Fluid can be overheated also. Whenever I do a brake job, I open the caliper bleeds before pressing the pistons back in to remove any contaminated fluid.

I keep my vehicles for many, many years. I'm not saying water in brake fluid is good, but my son's car(my old car) is 16 years old now and I never checked for water. Brake system is 100% original (minus pads and rotors) with 150k+ on it. And I live in a very humid environment.

Overheated fluid simply causes air bubbles to form which must be bled out. Once said air is removed, the remaining fluid is fine so long as there's <3% water in it.
You have a car with 16 year old brake fluid?

Hi Tractionless,

The Titan model 20 surge brake actuator manual specifies using DOT 3-4 heavy-duty brake fluid.

Best regards,

MYCO Trailers Parts. Dept.
941-748-2397
www.mycotrailers.com