I had a brake hose go bad on my 2015 F-150 while in the middle of no where. It was spraying fluid all over the place.
I limped to the closest autoparts store and they didn't have Dot4lv, only Dot 4. So I filled it up with that and the auto parts store gave me directions to the closest mechanic.
I limped there and they replaced the hose for me and filled the reservoir back up.
Do I need to worry about having some Dot 4 in my system vs the Dot 4LV?

 

You should bleed the system and replace with the correct fluid.

 

You WILL be OK
as 3 & 4 are glycol based fluids I believe. Not dot 5 though-- its silicone based

 

dot 5.1 is a traditional glycol ether/borate ester based fluid and compatible with dot 3 and 4, but it has a lower viscosity like dot 4 lv.

 

I know that 5.1 is-- but not 5. There is a dot 5 AND a dot 5.1- two totally different fluids that cant be mixed / used together in the same system as the 3 & 4

 

correct, I don't want someone who doesn't know to get confused because they couldn't just name the new glycol stuff dot 6 instead of 5.1.

 

Regular DOT 4 is not the same as DOT 4LV. The ABS system and other parts in the braking system may not work properly with higher viscosity fluid in it. I personally would not want to risk issues with something as important as braking.

 

Yeah- to me that was just stupid calling it 5.1

 

Some easy reading.

 

I just flushed my system a couple months back- it was easier for me just to get the 4 from the dealer which is 5 minutes away

https://www.f150forum.com/f118/flush...orning-496773/