HOW MUCH BRAKE FLUID DO I NEED AND SHOULD I STICK WITH THE OEM DOT 3?

[APPsBeast]

2018 1500 5.7 very much appreciate all your feedback

 

[caulk04]

I use at least a quart when I flush a vehicle. I also always use DOT4 which is a compatible fluid with higher boiling points.

Stay away from DOT5, it's incompatible. You likely won't find it on shelves anyway, but don't use it.

 

[APPsBeast]

I use at least a quart when I flush a vehicle. I also always use DOT4 which is a compatible fluid with higher boiling points.

Stay away from DOT5, it's
incompatible. You likely won't find it on shelves anyway, but don't use it.

I went with valvoline 3 and 4 is that ok?

 

[Bigskyroadglide]

I use lucus synthetic. DOT 3. Seems to be a reasonable fluid.

 

[tron67j]

I believe your manual calls for DOT 3, and probably says DOT 4 is okay if you cannot find DOT 3. My opinion, don't mix fluids in brakes.

 

[APPsBeast]

I believe your manual calls for DOT 3, and probably says DOT 4 is okay if you cannot find DOT 3. My opinion, don't mix fluids in brakes.

Oh shoot thats a mix? Dangit I thought it was just a compatibility rating for either or. ‍

 

[Burla]

Oh shoot thats a mix? Dangit I thought it was just a compatibility rating for either or. ‍

dot 3 and 4 are compatible and can be mixed, but when you do a brake flush you keep going until you see clean fluid, so not much is mixed. Dot 4 is 100% better then dot 3, and not all dot 4 are equal, if you want a long interval and better performance you look for a high dry or wet boiling temp brake fluid. So there are levels to which brake fluid: general use short term brake fluid is your dot 3, then if you are heavy duty a dot 4 is the way to do, then if you want a long interval and HD application you go up to a 400/600 wet/dry boiling temp fluid, these will be your real synthetic fluid and will cost a bit more. The average guy uses 4 pints to do a flush, do not let anti lock run dry, meaning the reservoir should never be below 1/2 full as you are filling and pumping.

Upfront cost is cheap dot 3 on sale could be 10 bucks, a good dot 4 not much more, but real 400/600 fluid starts at about 60 dollars for the 4 pints.

 

[Burla]

If you need more info...

Type Wet Boiling Point Dry Boiling Point Composition
DOT 3 400°F/205°C 285°F/140°C Glycol Ether
DOT 4 445°F/230°C 310°F/155°C Glycol Ether/Borate Ester
DOT 5 500°F/260°C 355°F/180°C Silicone
DOT 5.1 500°F/260°C 355°F/180°C Glycol Ether/Borate Ester


So those temperatures that are listed are the minimum requirement to make either dot three or dot 4, etc. But, if you research and compare brake fluids you see you can double the minimum dry boil by choosing a different oil, which means as fluid degrades those will have higher boils throughout the interval.

From link..

Yes, both Dot 3 and Dot 4 brake fluids are glycol-based brake fluids, which means that they are compatible with each other, and there is no problem at all mixing them.

If your car has Dot 4 from the factory, you should never refill it with Dot 3, though; but the other way is fine.

If you have Dot 3 in your car from the factory and you know that you are often driving with a trailer or in steep hills, I strongly recommend refilling it with Dot 4 instead...

Dot 4 has higher boiling points, making it better for all types of applications; even though it is often a little bit more expensive, it is worth getting it instead.

 

[Bob Macknight]

what does it say on the cap????????????????

 

[Burla]

As for dot 5.1, as you see in the chart can be great fluid and also is compatible with dot 3/4. However, that doesn't make it better then dot 4, again those are minimums, but there are many dot 4's that go above the dot 5.1 minimums. I would avoid 5.1 just because there is no benefit of it over high end dot 4's and the owners manual doesnt include them, and you don't want to accidentally get dot 5.0.

You can see brake fluids compared here. If you just look at the 400/600 wet/dry boils you will see best quality.

 

[Earl Zeis]

Be careful, not all replies know what they are talking about. Dot 3 and dot 4 are 100% compatible and will mix. Nothing new, always been that way. Some brands only make dot 4 and mark it dot 3 and 4. I always use dot 4 for the higher wet boiling point.

Dot 5 can't be mixed or used in a system that had dot 3/4 in it. System must be new or completely cleaned.


Earl

 

[APPsBeast]

Be careful, not all replies know what they are talking about. Dot 3 and dot 4 are 100% compatible and will mix. Nothing new, always been that way. Some brands only make dot 4 and mark it dot 3 and 4. I always use dot 4 for the higher wet boiling point.

Dot 5 can't be mixed or used in a system that had dot 3/4 in it. System must be new or completely cleaned.


Earl

Thanks Earl can’t find in manual what quantity of brake fluid to use, would you happen to know?

 

[Burla]

4 pints fills and allows you to pump clean through lines.

 

[Earl Zeis]

Thanks Earl can’t find in manual what quantity of brake fluid to use, would you happen to know?

I would think two quarts would be enough. Especially if you're not flushing the abs system.


Earl

 

[Dodge 1500 4X4]

Dot5 is silicone brake fluid cannot be used for anti lock brakes and not compatible with Dot3 or Dot4, Dot5 is used on Corvettes and top end cars with multi piston calipers it repels water in the brake system and is better for the calipers and seals.