PO says he converted to DOT 5, how do i check ?

[Recreateme]

The previous owner of my XS400F told me he 'convert the brakes to DOT 5" brake fluid... Is there anyway i can confirm this? and also what what does this conversion consist of?

I just don't want to dump in DOT 5 fluid into the brakes and have something horrible happen to my bike :S

 

[tjtoo]

Hi "dot 5" is just a different grade of brake fluid.
Just make sure that you top up (if needed ) with same spec fluid. It's readily available at most motor stores. Alternativley you can drain out the dot 5 and replace with fresh dot 4. Personally I wouldn't bother.
Just ride and enjoy.

 

[xschris]

I run dot 3 in mine and never had any issues. Like tjtoo said just drain it and put in what you want then you will know whats really in there.

 

[drewpy]

DOT 5 may be silicone (called 5.1) which if contacts with mineral, forms a sludge.

take a bit out and see if it mixes with DOT 4 (dot 3 is extinct round here now)

 

[RookieRider]

Hi, i googled "dot 5" cuz to be honest i had never heard of it....
I found several other forums (car racing,hot rodding, motorcycles),

-that say dot 5 gives you a spongier feel when applying the brakes.
-that mixing dot 5 with dot 3,4 or 5.1 is bad. (3,4,5.1 are glycol based, 5 is silicone based)
-that bleeding a dot 5 setup is harder than the other types.

They also discussed the dry/wet boiling points of each liquid.... but that's a whole different subject....

here is an interesting link....

http://www.advancepetro.com/differentbrakefluid.htm

 

[Recreateme]

Thanks guys- I did read that stuff about boiling points and just draining the system and replacing it, but I wasn't sure if specific parts had to be changed or if it was just the fluid.

I guess I'll buy DOT 5 and see how it mixes.

Posted via Mobile

 

[Lou Ranger]

... I guess I'll buy DOT 5 and see how it mixes.

You may want to hold off until you determine if you have DOT5 or DOT5.1 - here's a piece of a warning from British Cycle Supply:

You can go ahead and mix or flush (replace) any DOT 3, DOT 4, or DOT 5.1 brake fluids, no problem. So there are no special bleeding procedures and you don't need to run anything in the lines. The only one to watch out for is DOT 5 (silicone brake fluid).

DOT 5 does not damage paint like other brake fluids do, but is not recommended by AP Lockheed for use in their systems due to higher wear than with other type fluids.

Brake system contamination:

The single most common brake system failure caused by a contaminant is swelling of the rubber components (piston seals etc.) due to the introduction of petroleum based products (motor oil, power steering fluid, mineral oil, etc.) A small amount is enough to do major damage. Flushing with mineral spirits is enough to cause a complete system failure in a short time. I suspect this is what has happened when some owners change to DOT 5 (and then assumed that silicone caused the problem). Flushing with alcohol also causes problems. Brake systems should be flushed only with DOT 3 or 4.

If silicone is introduced into an older brake system, the silicone will latch unto the sludge generated by gradual component deterioration and create a gelatin like goop which will attract more crud and eventually plug up metering orifices or cause pistons to stick. If you have already changed to DOT 5, don't compound your initial mistake and change back. Silicone is very tenacious stuff and you will never get it all out of your system. Just change the fluid regularly. For those who race using silicone fluid, I recommend that you crack the bleed screws before each racing session to insure that there is no water in the calipers.

British Cycle Supply Company does not recommend use of DOT 5 silicone brake fluid on British motorcycles equipped with any AP Lockeed disc brake components.​

 

[xschris]

Good info I will just stick to Dot 3 its cheap and easy to get.

 

[Recreateme]

Fairly certain it was just DOT 5, not 5.1 because he said he switched because he didn't like how caustic DOT3 was and DOT5 was far less.

So with this information, its saying i should stay with DOT 5, because switching back would make it worse, and i should just drain my lines, and refill with DOT5 regularly ?