Dot 3 or Dot 5

[rustystud]

DOT 3 is actually designed to adsorb the water and hold it in suspension. I flush my brakes once a year and have clean brakes. An easy job with a remote reservoir.

I have taken apart brake systems with DOT5, water still gets in there but now you can't get it out.

If that was the case the brake lines would have rusted out long ago. If you take your truck into the water, of course you will have to service it, just like any system. The silicone system is still far superior to DOT 3. Ask any "ASE certified mechanic. Also when you "hold" the water in suspension it still will rust your lines ! That is why all OEM manufacturers say to completely purge your brake system every 2 years ! Read your owners manuals for your vehicles.

 

[JasonS]

If that was the case the brake lines would have rusted out long ago. If you take your truck into the water, of course you will have to service it, just like any system. The silicone system is still far superior to DOT 3. Ask any "ASE certified mechanic. Also when you "hold" the water in suspension it still will rust your lines ! That is why all OEM manufacturers say to completely purge your brake system every 2 years ! Read your owners manuals for your vehicles.

LOL. That is how I found the water. It settles out in the low areas and rusts. Brake fluid in a closed system lasts for much longer than 2 years; replacement isn't even listed in the maintenance schedule for my dodge ram.

 

[Hainebd]

Brakes on a deuce are not sealed but are vented to atmospher. Brake fluid absorbs water from the air. Brake system is single circuit type lose hydraulic, lose your brakes ( never rely on brakes to work on a deuce). With so much that can go wrong with brakes why not put the best in? O it is expensive. Don't drive your deuce then. Brakes are not the place to skimp. Pull all wheel cylinders, master cylinder, booster, every rubber line, inspect steel lines and replace suspect lines. Reassemble after flushing steel lines with DOT 5. Then bled brakes after adjusting them. Even then your brakes are still second to the model t mechanical brakes.

 

[JasonS]

Brakes on a deuce are not sealed but are vented to atmospher. Brake fluid absorbs water from the air. Brake system is single circuit type lose hydraulic, lose your brakes ( never rely on brakes to work on a deuce). With so much that can go wrong with brakes why not put the best in? O it is expensive. Don't drive your deuce then. Brakes are not the place to skimp. Pull all wheel cylinders, master cylinder, booster, every rubber line, inspect steel lines and replace suspect lines. Reassemble after flushing steel lines with DOT 5. Then bled brakes after adjusting them. Even then your brakes are still second to the model t mechanical brakes.

I believe yearly flushing with DOT 3 in a vented system is better than putting in DOT 5 and assuming all will be fine thereafter.

 

[welldigger]

I believe yearly flushing with DOT 3 in a vented system is better than putting in DOT 5 and assuming all will be fine thereafter.

I agree. I'm not a huge fan of dot 5. I have seen plenty of totally destroyed wheel cylinders and master cylinders because condensation sat on the bottom of them and caused major rust damage while using dot 5. Not to mention brake systems with dot 5 can be infuriating to bleed since the brake fluid can become impregnated with tiny air bubbles.

Nevermind the ridiculous cost. O, did I mention finding dot 5 can be a chore in itself? Not everyone's local parts store carries it and when they do its usually in tiny bottles. So the cost is even higher.

 

[Hainebd]

My point was not that using DOT5 was a cure all. I said even if the system was perfect and no moisture inclusion. The brakes on a deuce are slightly better than mechanical brakes on model T. The need to be checked always before during after you drive. If hydraulics are lost you have no brakes. Dot 3 is $8 a quart Dot 5 is $18 a pint takes a gallon to bled a deuce and wheel cylinders can not be flushed completely with bleeding.

 

[welldigger]

Dot 3 is $8 a quart Dot 5 is $18 a pint takes a gallon to bled a deuce and wheel cylinders can not be flushed completely with bleeding.

Thats exactly my point. When you bleed the system with dot 5 the moisture stays on the bottom of the wheel cylinders. With dot 3/4 the moisture is in solution with the brake fluid. So a system flush draws out most of the moisture.

 

[brokemansbudget]

i am new here. this is my first post or message. not real sure how to use this site and i am not sure this
post/message is even in the right place but i will speak here any way for now. i am looking to get a full list of all military cars/trucks,ect. that have a multi fuel engine. i have learned about the m35a2 duece & a half. wish to know what others have engines like this one that can run on most any fuel source provided it is mixed right.thank you in advance for your help.

 

[rustystud]

LOL. That is how I found the water. It settles out in the low areas and rusts. Brake fluid in a closed system lasts for much longer than 2 years; replacement isn't even listed in the maintenance schedule for my dodge ram.

http://www.kenwisechryslerdodgejeep.com/recommended-services.htm Here you go Jason.

 

[LiveFreeOrDieTryn2B]

I am redoing my brakes currently and had dot 5 and let me assure you every brake line,hose and wheel cylinder were rusted on the inside.

 

[LiveFreeOrDieTryn2B]

Look where your bleeders are on your wheel cylinders you cant get the water out if using dot5 because it doesnt absorb it I m using dot3 and a remote reservoir just felt safer knowing I can flush out all the water out.

 

[MarcusOReallyus]

i am new here. this is my first post or message. not real sure how to use this site and i am not sure this
post/message is even in the right place

Here ya go!


For newbies: How to start a new thread

 

[Hainebd]

Well I see we are in agreement. DOT 3-4 is best for the Deuces brake system. That is what I use and have used. I will say the first flush had blobs coming out the bleeders. I agree bled yearly. Remote res is the only way to be sure to check fluid before u drive. Never mix brake fluid.

 

[weld88]

So just now started reading this post and I ran into the same issue not knowing if I had DOT 3/4 or DOT 5. My finding pretty much pointed strait to DOT 5. it's already been said in the few post back but all I did was reach a small ear dropper down in my master cylinder got just a small sample and mixed a little water with it in a medicine cup (see pic)

You can see how the water separated. Now as far as which one is better I'm not sure, I am going to continue to run DOT 5 in mine my 2 cents on it is basically the military and m35a2 manufactures put DOT 5 in for a reason (not saying DOT 3/4 won't work) which bring an engineer myself it must be what they felt was best.

 

[Hainebd]

I agree with DOT 5 being better fluid. The issue is water inclusion. If we had a diaphragm to seal the system that makes more sence. But open to air moisture may get and DOT 3-4 will absorbe as DOT 5 will not. It will settle into MC then into booster. With time to WC. SO BLED YEARLY. You will service atleast yearly so add bleeding to the list.

 

[MarcusOReallyus]

Now as far as which one is better I'm not sure, I am going to continue to run DOT 5 in mine my 2 cents on it is basically the military and m35a2 manufactures put DOT 5 in for a reason (not saying DOT 3/4 won't work) which bring an engineer myself it must be what they felt was best.

I have been following this debate for a couple of years now, and not just on this forum. I have read a lot on both sides of the issue. For me, weld88 nailed it. The military has a lot of experience with this stuff, and I'm going to throw in with them on this.


BTW, they have gone back to DOT 3/4. Their fling with DOT5 is over, from what I've read.

One of these days I hope to do the disc brake rear conversion on my 1028, and I'll go through the entire system then and rebuild it, new brake lines, the whole shebang. And I'll fill it with DOT4.

 

[glcaines]

I'm sticking with DOT 5.

 

[JasonS]

http://www.kenwisechryslerdodgejeep.com/recommended-services.htm Here you go Jason.

This is not an OEM requirement; it is a dealer suggestion (probably an attempt to drum up business). BTW, I checked the owners manual from my wife's 06 Pontiac; doesn't list brake fluid replacement either.

 

[MarcusOReallyus]

This is not an OEM requirement; it is a dealer suggestion (probably an attempt to drum up business). BTW, I checked the owners manual from my wife's 06 Pontiac; doesn't list brake fluid replacement either.

I never heard of anybody suggesting regular repacement of brake fluid.... until I read this thread.

 

[JasonS]

Found this; no idea if it is correct: "General Motors and Chrysler do not mention brake fluid in their scheduled maintenance recommendations. A General Motors spokesman said Delco Supreme 11 DOT 3 brake fluid contains additives than many other brake fluids do not, so it is essentially a lifetime fluid. Starting in 1993, GM began using a new type of rubber brake hose with an EPM lining and outer jacketing that reduces moisture penetration by 50%. So GM does not consider fluid contamination to be a significant problem."