Dot 5 brake fluid?

[Jason Mills]

Has anyone used it successfully in their truck?

I tried using it 20 years ago and never got a brake peddle that was satisfactory. I have heard that the military uses it or has used it in the past. Is this true?

Thanks,
Jason

[Kevin in Ohio]

I'm using it in my modified but it has Hydroboost and 4 wheel discs on it. It'll put you through the windshield. The only thing I noticed was the fittings have to be tighter than normal to prevent any leaks. Other than that, no difference so far other than no paint damage. ;)

[Jason Mills]

Thanks Kevin for sharing your experience.

Wow! "Craftsmanship" does not describe the artistry involved in that picture.

The fact that it needs a tighter connection on the brake lines makes me wonder if I would have trouble with the wheel cylinders leaking..

[Kevin in Ohio]

Thanks Kevin for sharing your experience.

Wow! "Craftsmanship" does not describe the artistry involved in that picture.

The fact that it needs a tighter connection on the brake lines makes me wonder if I would have trouble with the wheel cylinders leaking..

I used all over the counter rebuilt calipers and have had no leaks in 4 years. No leaks or retighten on any of the lines either. I used all stainless lines and fittings too.

[Matthew Ziegler]

dot 5

I used the purple military surplus dot 5 in my m37 for a few years, had to bleed the brakes at least 4 times to get all the air out. When I switched over to a Chevy master cylinder and disc brakes the lid on the mc. said use only dot 3,so I flushed the lines and switched to 3. Motorcycle mechanic friend of mine says Harleys use dot 5, he claims it has a much higher boiling point.

[bmhenry]

DOT 3&4 can be "mixed" without issue. However DOT 5 cannot be mixed and needs to be stand alone. It does indeed have a higher boiling point and is what my Harley requires as well.

[wecluis]

I also use DOT 5 also, and no problems/leaks whatsoever.

[El Muerto]

I use dot5 all the way around. I will never put dot 3 back in anything its wasted more shop time, money and parts than almost anything..except 10 year old gasoline.
Things to be aware of are;
It will evaporated slowly over time so check your levels regularly.
It doesnt absorb water so any condensation that enters the system will pool at the lowest point. Always bleed a bit out before the first freezing temperatures to be safe..i guess there is the potential for that water to boil in the wheel cylinder which may account for reports of dot5 becoming compressable and creating fade under extreme braking. I have never experienced a soft pedal as i would expect from this condition , but stock M37 brakes do fade and i have experienced that.
All of my trucks either already have dot5 or are waiting to be converted.
My ct800's have it in the hydraulic clutch.
An excellent tip is to use a little dot5 on the die, prepped line and on the tool for the second operation when making a double flare. You will be happy with the results.
Syl-glide rubber grease on all your rubber parts