Might want to check out Dot 5.1, from what I've read 5.1 is compatible too. I upgraded my 2013 Wrangler brake system last brake job w/ Dot 4 because it was on the shelf.

I haven't any complaints about the fluid. Having done the brake fluid flush along w/ brakes (drilled and slotted rotors) at the same time I can't say whether any increased brake performance was because of the fluid alone.

 

DOT 5.1 is silicone! Not compatible nor as friendly as you think. No real benefit other than longer life and requires serious flushing with original brake system.

Here is a main reason why DOT5.1 fails big time. Water is displaced by the fluid. Sounds great until the brakes heat up and water turns to steam. Since silicone displaced water, air pockets will developed. Causing spongy feel at the pedal or failure with ABS actuation.

 

Use Bosch ES16-32N is all you need.

I found that unless you run track you'll need DOT4 and aftermarket calipers. Jeeps and most cars don't have Stainless Steel pistons, and will seize before you even get worrying about brake fluid temps.

To get the most out of your brakes stick with semi-metallics. There are a few over the counter brands made for law enforcement or fleet vehicals. They out perform the ceramics that are flooding the market. I also found only one manufacturer makes heavy duty emergency brake shoes, which are better than what other brands use for longevity and performance.

Don't buy into slotted and drilled rotors too.

 

To get the most out of your brakes stick with semi-metallics. There are a few over the counter brands made for law enforcement or fleet vehicals. They out perform the ceramics that are flooding the market. I also found only one manufacturer makes heavy duty emergency brake shoes, which are better than what other brands use for longevity and performance.

Don't buy into slotted and drilled rotors too.

I'm looking to replace my pads after having gone w/ Detroit Axle a few months ago. The rotors are fine, the braking performance is great, and I have great experience w/ their drilled and slotted rotors, but the pads are annoying (squeal). The pads are ceramic and not what I expected concerning noise level but for the price of the brake kit I can't complain. Haven't decided which pads to go w/ but I'm looking for recommendations on brake pads (quiet). I'm not in a hurry since the current pads are new, perform great, but are noisy.

As for brake fluid 5.1 is listed as compatible but that's about all the research I have done. I'm using Dot 4 at this time.

 

I had accidentally bought a big bottle of DOT 4 brake fluid just to have on hand to do an eventual brake flush, and have been wondering if it would be OK to use on my 2022 JL (the owner's manual calls for DOT 3).
I guess the answer is "yes", then?

 

I had accidentally bought a big bottle of DOT 4 brake fluid just to have on hand to do an eventual brake flush, and have been wondering if it would be OK to use on my 2022 JL (the owner's manual calls for DOT 3).
I guess the answer is "yes", then?

The brake fluid bottle of Dot 4 I have, says compatible w/ Dot 3 or 4 brake fluids. From what I've read Dot 4s are all compatible w/ Dot 3 brake systems/fluids. As well, 5.1 is glycol and compatible w/ either Dot 3 or 4.

 

I ordered this Synthetic Dot 3/4 brake fluid. I am just getting ready to change so can't report on the improvements. I was looking at the Motive brake bleeder. Anyone have any comments on them?

https://www.amsoil.com/p/amsoil-dot-3-and-dot-4-100-synthetic-brake-fluid-bflv/?zo=226468

 

One man brake bleeders are time efficient but having wife or other pump the brakes work fine too. I haven't run into problem w/ brake bleeding my Wrangler. Most of the problems I see from others running into bleeding problems are from either a brake hose collapsed or inexperience, quite a few people unknowingly install calipers upside down w/ the brake bleeder at the bottom (the brakes won't bleed).

Last time I used a one-man brake bleeder was in the shop decades ago the shop purchased it to not pull others off their flat rate jobs.

 

yes post above confused dot 5 with dot 5.1

Brake fluid DOT 5 is a silicone-based fluid making it incompatible with anti-lock braking systems. Additionally, DOT 5 cannot be mixed with other brake fluid types and unlike other fluids, it does not damage the paintwork.

This fluid is engineered for demanding applications like military vehicles and extremely cold climates.

Brake fluid DOT 5.1 uses glycol ether and borate ester compounds but has an enhanced performance like the silicon-based DOT 5. We can say that it is a non-silicone version of DOT 5 but compatible with DOT 3 and DOT 4 types of braking systems and fluids.

All glycol-based brake fluids need to be handled carefully because they can damage the paintwork of the vehicle or motorcycle.

CAN WE MIX BRAKE FLUIDS?
Yes, but with certain exceptions.

Brake fluids can be mixed only if the fluid that you add to the system belongs to a higher grade.

For example, a braking system that has a brake fluid DOT 3 specification can use a DOT 4 or a DOT 5.1 fluid. Also, a system with a DOT 4 can be topped up with a DOT 5.1 without bleeding the system.

However, never top up a DOT 4 system with a DOT 3 brake fluid. DOT 3 won’t be able to meet the temperature requirements because of its lower dry and wet boiling points.

Once again, do not mix DOT 5 with any other type of brake fluid because of its silicone-based composition.

For optimal braking system and brake fluid performance, it is best to bleed the brake fluid and replace it with a fresh one.

all above from
Vavoline

Vehicle Maintenance: Brake Fluid DOT 3, DOT 4, DOT 5.1, and DOT 5 - Valvoline™ Global Europe - EN

Brake fluid selection is a particularly important task of vehicle maintenance. Different types of brake fluids match the requirements of specific braking systems...

www.valvolineglobal.com

 

again they conflate dot 5 - not mixable with older with dot 5.1 which is mixable with older I guess details get overlooked even when listed out for them

 

@Digger84 I'm going to nickname you "Dotty".
In all seriousness thanks for the clarification. I only learned about Dot 5.1 rather recently. I suppose this is why ASE certifications expire every five years. All my ASEs expired a decade and half to two decades ago.

 

Here's a great comparison chart. Brake Fluid Comparison Shopping

Castrol React SRF is the winner.
Motul RBF 600 is a kind of hi-perf bargain when you look at the wet boil.

For a street vehicle that doesn't get the fluid changed every weekend, I'd use the wet boil point for the comparison. I use cheapo Prestone from the local parts store, since I have huge 14" 4 piston brakes and don't tow or race. I just don't have a use that will get the fluid hot.

 

Here's a great comparison chart. Brake Fluid Comparison Shopping

Castrol React SRF is the winner.
Motul RBF 600 is a kind of hi-perf bargain when you look at the wet boil.

For a street vehicle that doesn't get the fluid changed every weekend, I'd use the wet boil point for the comparison. I use cheapo Prestone from the local parts store, since I have huge 14" 4 piston brakes and don't tow or race. I just don't have a use that will get the fluid hot.

I did not see viscosity data listed. Glad you did not pick a DOT5.1 fluid for a Jeep. The reason why I specified Bosch ESI 6-32N is that it is actually a DOT4. From what I gather there are two Bosch ESI 6 fluids and this one is the better of the two. Price is $10 on RA site. Got it with my severe duty pads for my HD brakes. I am a practical guy. Semi-Metallics are better than ceramics hands down in a jeep and cheaper to replace. If anyone is using oem calipers, your pistons will start seizing before your brake fluid degrades from heat. Just look up phenolic pistons and heat. I don't mind seeing better out there, but cost of operation and comparing low gains from very good to using the best makes practicality my choice.

 

Yeah ceramic pads are fine for general purposes. They are clean and wear a long time. If you want more hot friction coefficient, semi-metallic will get you that at the cost of lower cold friction coefficient, higher rotor wear, black dust, and higher pad wear. These are variables which are more or less intense based on blend ratios and materials.

I run a low metal, semi-metallic pad, Teraflex Delta 14"x 1 1/4" vented rotors, 4 piston calipers, with metal pistons. My choice of fluid is bland Prestone DOT 3 because I don't get the brakes hotter than they can get in one highway stop. So, fluid temperature is not an issue for me. But even with 37s and loaded, my JLUR can stop like an Italian sportscar. These brakes never cease to amaze me. Worth their $ for my needs.

https://teraflex.com/delta-brake-system-front-rear-5x5.html

 

Actually the semi-metallics have the best cold weather coefficient and are more linear with temp ranges. But that is best if you live in mountain country or offroad winter style.

I do admit bigger brakes are mandatory if going beyond 33s big heavy tires will limit braking abilities, which will heat up your brakes much more with stock brakes. I rather spend money on big brakes than to toss it in sooner brake flushes. At least the Bosch fluid will extend your fluid change intervals without going to Dot5.1. They say it is 100% more life than DOT3 and 50% more than DOT4.

 

Been using Bosch ESI 6-32N for over 100k with zero issues in BBK.

Amazon.com: BOSCH ESI6-32N Brake Fluid (Direct Replacement for DOT 3, DOT 4, and DOT 5.1) - 1 Quart : Automotive

Amazon.com: BOSCH ESI6-32N Brake Fluid (Direct Replacement for DOT 3, DOT 4, and DOT 5.1) - 1 Quart : Automotive

www.amazon.com

 

My JL 4 door with 37s, wouldn't brake hard enough to activate the anti-skid system, with the OEM optional "big brakes". That was my tipping point on going with the Teraflex Delta brakes. I spoke to a friend that tried a brand of "big brake", on his JL 4 door with 37s, where they use the OEM calipers and larger rotors. He said he still didn't believe they were adequate for his needs, after some bad experiences.

 

Nobody has yet addressed Unkown's previously made point, that using a different grade of brake fluid than recommended for the vehicle might have a different viscosity, and therefore impact the ABS system. Might there be anything significant there?

 

Here's some additional info on brake fluids. It looks like the critical aspect of viscosity is its cold temperature viscosity effect on ABS. Brake fluid - Wikipedia

 

Most everything I read suggest lower viscosity is as good or better in ABS as it flows thru small orifices better
some have comment that at very low TEMP dot 5.1 may have higher viscosity than dot 4+

for example

https://bobistheoilguy.com/forums/threads/low-viscosity-brake-fluid.237122/

but I think even very low temp DOT 5.1 is not more viscous than dot 3

 

your link was way off with this FAQ bullet 1
as it is labeled dot 5.1 but is referencing dot 5 properties

 

@Digger84 I removed that source because of the misinformation linked to the faq.

 

Not to question what you are doing but I have a 2024 Gladiator (JTR) in addition to my 2016 Willys JKU. May I ask why you would be changing the brake fluid on a year old vehicle? I didn't even give it a thought on my 2024 JTR yet. Am I missing something?

 

If you use your jeep off road, or wet areas, or towing... as with any HD vehical you should replace yearly. If your jeep is a garage queen every 2 to 3 years. Moisture will find its way into the fluid during operation. Yes you can wait every 10 years but hydraulics now operate without your interaction, when you have grade logic and advanced safety controls. Down hill cruising will maintain speed actuating the brakes without your foot do the work. You may find that being done more often than you think.

 

I did a full flush on my JK and Grand Cherokee High Altitude this year and used Prestone Max Synthetic Dot 3. I believe it has a higher boiling point. I tend to stick to what the OEM says for fluids. I noticed a much more significant difference in both vehicles braking systems than what I thought I would. They are working great and the pedal is firmer and stopping length has decreased. Feel like I got my brakes back. I went through almost two 32 ounce bottles on each vehicle doing the flush and fill and admittedly over do things.

 

You probably did not replace pads on both. If not wanting to waste so much fluid, new pads will make the pistons seat down into their bores. In doing so less fluid is pumped out to flush, if at first emptying the reservoir of old fluid before adding new to flush.

I just replaced the factory pads on my brakes (from 2019). They seem to be ceramic. In checking pedal firmness the pedal is a little spongy from last year, before adding 20k on the ODO. I noticed it before the pad upgrades. This the reason I'm going full tilt in a complete break job. New fluid will not improve pad performance just allows pads to properly grip under pressure. You just released your pads potential.

as for the original ceramics they have gone over 105k on long distance travel with 35% life left on the pads. Since I live in the mountains, I need better and more linear performance than ceramic. Thus my carbon metallic choice for extreme duty.