Brake fluid.

[ken]

We started working on the brakes this weekend. And had them working pretty well for about 2 miles. Then the right front wheel cylinder started leaking. It appears to have DOT 3 Fluid in it. Is anybody using DOT 5? Any problems?

 

[AceHigh]

Is anybody using DOT 5? Any problems?

Uh, the military?

 

[2Deuces wild]

I flushed out the 3 dot with 5 dot about 6 months ago and have had no trouble to date knock on wood.

 

[m376x6]

The only thing I have found on changing a DOT 3 system over to a DOT 5 is that you have to completely flush your brake system with a non residue brake flushing compound. Supposedly most brake systems are compatible with DOT 5, I have heard some folks who have had troubles after trying to change over to 5 however, perhaps they didn't flush the system well enough or not at all. Or the cups and other rubber parts weren't compatible with silicone. Even though DOT 5 is not hygroscopic, it doesn't mean that moisture will not collect in the low lying areas of the brake system and will therefore still corrode the brake lines etc..

Regards,
M376X6

 

[Recovry4x4]

Try TB 43-0002-87. Right click link to save.
http://old.steelsoldiers.com/index.php?module=pagesetter&type=file&func=get&tid=1&fid=file&pid=67

 

[papercu]

DOT 5 will not help or prevent any leaks and will cost a lot more (money and time). If you drive your truck regular DOT 3 is great. Wayne

 

[nattieleather]

I agree you need to address the leak issue and then decide whether or not to change. I've used Dot 5 in all my MVs and have been very happy with it.

 

[NDT]

I put silicone brake fluid in my M135 in 1983 and all 12 wheel cylinders, the air pack, and the master still work great. Dot 3 and it would be a crusty mess. I hate doing work over and over.

 

[papercu]

Nature of the beast! If you let a truck sit, DOT 3 will absorb moisture if you drive it, no problems. Wayne

 

[ken]

Thanks, Guys. As far as the leak goes i've ordered 4 new wheel cylinders. And i already have a master cylinder rebuild kit. We are going to flush everything out and repace the fluid anyway. When we bled them, rust, water and sludge came out of the bleeders. So i can't take any chances. I wanted to keep all my MV's using the same supplies. As much as possable. And that was my thinking of changing to DOT5. I wanted to make sure the M37's cylinders were compatible.
Kenny, Thanks for that info it's a good read.