Dot3,4,5, why

[DEUCEBIGALOW]

My brake system is open and when I fill this up and get it stopping again, why cant I use DOT3 or DOT4 and if I cant why not not and If i can whats the downfall...

 

[Recovry4x4]

I use DOT 5 exclusively. Why, because they don't make DOT 6. Both will work for you. DOT3 is cheaper. Both will stop you but DOT 5 won't absorb water like DOT 3. There are multiple sides to both stories, good and bad points for each one. Pick one you are comfy with and get it going.

 

[Marlboro]

the other problem with changing to one of the others is the amount of work needed. you will need to rebuild or replace all parts of brake system that has contact with fluid.. it will as need to complty fluse system u do not want to mix them.

 

[DEUCEBIGALOW]

Well the MC is completly dry.. So i figured I would ask.. But the 7.99 for 11 ounces was a big shock when im used to paying that much for two quarts worth.. Any body know what the whole system will hold Im sure its prob at least a quart worth ..

 

[Jake0147]

DOT 5 is the retrofit. DOT 3 is what the OEM of the brake components built the parts for. Use whichever you like.

 

[AceHigh]

Usually about $40 a gal on the surplus market

 

[Tow4]

I used about a gallon of DOT 3 when I replaced all the wheel cylinders and rubber hoses.

 

[hndrsonj]

You can find DOT 5 fluid reasonable at Surplus dealers. My last 2 gallons were $10 each. The most expensive i've bought were $32. When I find them cheap, I stock up and never buy from a parts store.

 

[DEUCEBIGALOW]

Ya ok that pretty much makes life alot easier. thanks for all the help so far guys. Now maybe im not seeing something here but on a norm rig you open the MC and put fluid in it... The only way i see to do it in my truck is to open the trap door and take that line off the top of the MC and then pull the cap off.. Am i doing this wrong it just doesnt seem right.

 

[cbvet]

You're doing it right.
FWIW- I'll be changing all of my trucks to DOT 3 whenever major work is needed.
All you need to do is flush the DOT 5 out with 3.

 

[maxxplanck]

where can I get DOT 5, dont see it around much. Does Napa carry it or autozone ?

 

[Floridianson]

My NAPA carries it but take some lube with you so it don't hurt so bad.

 

[hndrsonj]

Do NOT buy it from an auto parts place! Get it from a surplus place like FLMV, Muttparts, Franks, EBAY etc. If you do change to DOT 3 make sure you remove all DOT 5 and change the stencil to DOT 3 ONLY so the next buyer doesn't put in the fluid that is called for in the manuals.

 

[wdbtchr]

If you shop around on epay a little you can find it around $25 to $30 a gallon pretty often. I recently found a case(12 bottles) of 12oz bottles for $26 plus $10 shipping. I like the small bottles for topping off, keep a couple in each truck. I'm sorry there isn't enough lub to buy it at a regular auto parts place.

 

[DEUCEBIGALOW]

Ya they want 8.99 for 11oz at autozone OUCH.. vs $3 for 32 ounces of the DOT3

 

[hndrsonj]

Ya they want 8.99 for 11oz at autozone OUCH.. vs $3 for 32 ounces of the DOT3

You can get it ALOT cheaper.

 

[ODdave]

Personaly I find the price difference a small price to pay as the dot 3&4 are hydoscopic and can destroy a brake system even when it just sits there. The dot 5 being silicone repels water and cotes the internals helping to prevent rust. "I'd rather dump oil on my truck than salt"

 

[popacom]

The downside of the DOT 5 is the spongier feeling pedal, I am not an engineer
but a friend who is explained it that Silicone molecules compress at a different rate.
All I know is the rubber components seem to like the DOT 5 better and it won't peel
paint like DOT 3 and if you spill it on CARC paint you can clean up with Lacquer thinner
with no bad effects on the coating.

popacom / BILL in Ky

 

[storeman]

This may sound stupid, but the two trailers i bought have working surge brakes and how do you tell what the MC has in it? difference in color between the DOTs? If so, what color is which?
Jerry

 

[doghead]

So, after 20 minutes of searching several terms or combination of terms, I found the thread I was looking for. Please try the search function, along the way(just now) I found a bunch of good threads to read.

http://www.steelsoldiers.com/safety/7031-brake-fluid-how-tell-kind-you-have-dot-3-dot-5-a.html


btw, simply seaching"brake fluid" I had like 1000 results. again, using descriptive titles helps alot when searching.