The car uses 3 but why not put. 5.1
150k miles auto 11 Silverado
should I buy 2 quarts or one will do. Most online say one should do but I want to double check.
thanks in advance!
'Changing' tends to imply you want to exchange all the fluid, so go ahead and flush the system. The quantity you need is in your owners manual. You're better off having too much instead of not enough, so you could just grab a gallon of DOT 3 at Walmart for $25, which is a lot more than you'll need. Also ABS brakes need a scan tool to do even a simpler brake bleeding.
@hixster since I’m flushing it I’m not really limited to 5.1 and can use the dot 6 right?
@whatsacar You should use the type of brake fluid recommended for your car, which is DOT 3.. It was designed to use that. Don't try to re-invent the wheel here.. "If it's not broke don't fix it"!
The car uses 3 but why not put. 5.1
Stick to what the owner's manual says. Unless you plan on drag-racing your truck, and doing it multiple times in a row, DOT3 fluid is fine. DOT3, 4 and 5.1 are based on boiling points. The higher the DOT, the higher the boiling point. If you're not constantly locking up your brakes and smashing the gas all the time, DOT4 and 5.1 are overkill.
@justin-shepherd oh gotcha lmao I just through when your driving and traffic it could have the boiling point high. Gotchya thanks!
@justin-shepherd also, if using a 5.1 I would have to change less because it absorbs less water than the 3,4 right?
also, if using a 5.1 I would have to change less because it absorbs less water than the 3,4 right?
All alcohol-based fluids absorb water over time, even in brake lines. Alcohol is hydroscopic. Doing a brake fluid swap once every 5-to-7 years is already minimal; that truck should have only changed brake fluid 2-3x.