Wilsons Sandbox

--- In DSN_klr650@y..., "closeke" wrote:

> Is Dot5 better than Dot4? What is the difference?

I got this info off an auto racing website. I'm sure it would apply to our bikes as well... DOT 2 spec brake fluid is for drum brakes and is now obsolete. DOT 3 and DOT 4 fluids are for todays modern braking systems. DOT 5 brake fluid is silicone and SHOULD NOT BE USED. It is not compatible with DOT 3/4 fluids, can bubble easily when being poured into the system, and can cause your brake system to corrode.

>Is Dot5 better than Dot4?

True DOT 5 is synthetic, CAN NOT be mixed with anything, and SHOULD NOT be used on, really, just about anything. I can't think of a single car or bike offhand that still spec's DOT 5. Now DOT 5.1 is a different story, not synthetic, and can be freely mixed with DOT 4 or 3. In most cases, however, a good DOT 4 like Castrol LMA should work great on motorcycles.

On Tue, 26 Feb 2002, bsetliff wrote:

>DOT 5 brake fluid is silicone and SHOULD NOT BE USED. It is not >compatible with DOT 3/4 fluids, can bubble easily when being poured into >the system, and can cause your brake system to corrode.

DOT5 is really goofy stuff with some bizarre characteristics. All of the rubber in the system must be made to withstand its formulation, although this has supposedly been corrected in modern formulations. DOT5 does not absorb water, which is what's supposed to be so great about it. Instead, you get localized corrosion since the water pools at the low points in the system. It's also slightly compressible - not good for brake feel. DOT5.1 is different stuff entirely. It's more like a high-performance version of DOT4. My fluid choice is a regular off-the-shelf "DOT3/4" fluid. This is DOT4 that is supposed to be suitable for use in all DOT3 applications. I don't know if I'd want to try it in a late-model ABS-equipped system that calls for DOT3, but it should be fine in a KLR. RM

So what's the purpose of DOT5 if one isn't ever supposed to use it in brakes? -Lujo [Non-text portions of this message have been removed]

On Tue, 26 Feb 2002, Lujo Bauer wrote:

>So what's the purpose of DOT5 if one isn't ever supposed to use it in >brakes?

Beats the hell out of me.

I believe DOT5 fluid can withstand higher temperatures (frequent & hard braking - racing?) and it also is not as harmful to painted surfaces. It is not compatable with DOT3-4 stuff without completely disassembling the caliper and master cylinder to flush out the old fluid before replacing it with DOT5. DOT3-4 should be sufficient. Just make sure you bleed the brakes properly and you are set to go for another year. Tom '01 A15

--- In DSN_klr650@y..., RM wrote: > > On Tue, 26 Feb 2002, Lujo Bauer wrote: > > >So what's the purpose of DOT5 if one isn't ever supposed to use it in > >brakes? > > Beats the hell out of me.

Lujo Bauer wrote:

> So what's the purpose of DOT5 if one isn't ever supposed to use it in > brakes?

I'm sure that back in the eighties the DOT5 stuff seemed like a good idea at the time, but then DOT5.1 was invented. The only problem with typical polyglycol brake fluids like DOT3/4/5.1 is that as the boiling point goes up, so does their ability to absorb water. Mister_T Melbourne Australia

--- In DSN_klr650@y..., RM wrote:

> On Tue, 26 Feb 2002, Lujo Bauer wrote: > >So what's the purpose of DOT5 if one isn't ever supposed to use it > >brakes? > Beats the hell out of me.

I think DOT5 is used in older cars, like muscle car restorations and stuff like that. I've just been told never to use the stuff with modern braking systems, although I am not familiar with the 5.1 stuff. Just use DOT4 and you'll be set.

I thought Harleys used it. (really)

----- Original Message ----- From: "Lujo Bauer" Cc: DSN_klr650@yahoogroups.com> Sent: Tuesday, February 26, 2002 12:27 AM Subject: RE: [DSN_klr650] Re: Dot5 brake fluid > So what's the purpose of DOT5 if one isn't ever supposed to use it in > brakes? > > -Lujo >