i think you can mix but dont remember.....but why was your brake fluid low?

also have you already "flushed" your brake system? if not go ahead and replace all of it



BTW....the bottle should say if you can use it or not

 

yes it should mix, i havent come across one that doesnt say that it does mix. I flushed mine out completely though when i did mine. It was dirty and I wanted to flush it. So I tried synthetic for shits and giggles.

 

have you tried that dot 4 yet?

 

no what i did was i bought some stuff that said dot 3/ dot 4 compatible so i dont know what it is exactly

 

I don't know why it's low, I checked it the other day and it was at "ADD" so I figured I should fill it. Exactly how do I flush the entire system? I'll do a search to see what I can come up with, but any help would be greatly appreciated.

 

Unless it's leaking somewhere (look for wetness near the wheel cylinders and calipers) it's likely just that the brakes are wearing and there is more fluid in the calipers due to less pad material...perfectly normal.

Basically you just bleed the brakes (refilling resevoir as needed, never let it get empty) until you get clean fluid at the wheels. Start at RR, then go LR, RF LF when you do it.

 

So you take the brake lines off down at the calipers and let the fluid drain until it's the clean stuff you've been pouring into the resevoir? Do you need to take the wheels off to get at the lines?

 

I just did this last night. I used a clear hose, and a glass jar. Put the hose on the bleed screw, and the other end in the jar. Then all you need to do is have a friend pump the brake pedal until you see clean fluid come out the bleed screw. Of course, don't forget to keep checking the master cylinder level. Repeat for each brake going in the order that caulk stated. It is going to take about 2 large bottles of fluid, so if you don't have that much, better go get more.

 

Okay where is the bleed screw located at? I know nothing about brakes, details here guys.

 

Dot 3 & Dot 4 brake fluids are mineral based fluids. Dot 5 is the synthetic fluid. Dot 3 & Dot 4 WILL mix but NEITHER WILL MIX with Dot 5!!!! Dot 3 is the standard fluid and Dot 4 is more for high heat situations such as emerengcy vehicles or for road racing. To my knowledge (may be wrong) but there is no such thing as a synthetic Dot 3 brake fluid. I would re-read you label to verify. You are asking for serious trouble if you mix Dot 5 synthetic with either Dot 3 or Dot 4 brake fluids.

Edit: The bleeder screws are on the back of the calipers on the front and top center on the inside of the rear drum on the backing plate. They resemble a grease fitting but don't try to grease them.

bwdakrt

 

http://www.valvoline.com/pages/products/product_detail.asp?product=51

 

I stand corrected on one of my statements being I call Dot 3 & Dot 4 mineral based. It is gylco based. The Valvoline, even though they advertise it as a full synthenic fluid, is not full synthentic (which would be silicone based) it is gylco based. Check the ingredients: http://msds.ashland.com/ShowMSDS.as...DS.asp?M=0330094&C=005&D=503&L=EN&F=ANSI&N=SYNPOWER+DOT+3&4+BRAKE+FLUID+6/12+OZ

Now to back up my previous statement, this article was written in 1999, but is still true today. http://www.sdvsa.org/BrakeFluidFacts.htm

Dot 3 & Dot 4 fluids are gylco based and Dot 5 Synthenic is silicone based and neither of the two should ever meet.

bwdakrt

 

yeah but who says it has to be silicon to be a synthetic? It just says dot 5 is synthetic and a silicon fluid. synthetic motor oils aren't silicon based.

wouldn't the fact that its primarily ester based make it more a synthetic? It might not be fully synthetic like they claim (it could be too, i dont know that much about this stuff). But it doesnt seem to be a mineral oil to me.

 

You are correct about the fact that it is NOT mineral based. That statement was wrong on my part. I guess the best thing to do is always check the label. Unless your vehicle recommends a silicon based fluid, don't use it. I can see where Valvoline calling their fluid a Full Synthenic would be confusing. I know it is to me.

ShadowRango, do what you said about topping it off and I apoloize to you for confusing the situation.

bwdakrt

 

I think I'll just top off the resevoir until I go back out and buy more fluid lol. I'll make it simple.

 

No you're fine Grandpa, I was just saying that I don't really feel like screwing with my brakes right now and bleeding them all. There was some good information on that site you gave, and learning more never hurts!