| Author | Message | ||
     Jolly |
I bought a used Nissin remote reservoir front master cylinder for my 96 S1.. (just cause... ) anyway, the cap says use DOT 4 only, the cap on the 96S1 says use DOT 5 only... which fluid should I use? the master cylinder had DOT 4 in it and was used on an S2 from previous owner who had no problems with his brakes at all.... (fellow BADWEBer who is methodically going through his S2) so...which fluid should I use? if I use DOT 4 like the cap says then I will never put the wrong fluid in the reservoir, if I use DOT 5 then I am keeping the brakes plumbed with what the factory called for, but different fluid than cap calls for and I see a potential problem with that one for sure!!! I will be using a mighty-vac had pump to completely flush the system.... as a comparison I checked all of my Buells: 95 S2: DOT 5 96 S1 DOT 5 98 S1W DOT 5 99 X1: DOT 5 2002 S3T: DOT 4 thoughts on what I should put in this? | ||
| Buellistic |
IMHO, clean the lines, caliper, master cylinder and use DOT 5 as it is the better fluid ... | ||
| Rocket_in_uk |
You cannot mix DOT 4 and DOT 5. If you intend to use the reservoir that's had DOT 4 in it, and your system currently runs DOT 5, then you must thoroughly clean and dry the remote reservoir and any of its related components if you intend to use any of them (pipework, fluid bolt fittings). You can then use your remote reservoir using DOT 5 as is already in the system. I would run plenty of DOT 5 through your system when bleeding as a brake fluid refresh is a good thing. http://www.opieoils.co.uk/pdfs/tech-articles/Brake -Fluid-Explained.pdf Rocket in England | ||
| Phelan |
Sorry to cause you more work David! As long as you flush the M/C good, running DOT 5 in it will not be an issue. | ||
| Jolly |
NO WORRIES!! you know me... gotta have a project!!! just searching for the best way to do this. looks like flush the master cylinder (since its the new piece to the system) with denatured alcohol to clean out the DOT 4 and run DOT 5 since the bikes complete system has DOT 5, the easier job is to flush the master cylinder and just run what the complete system uses. thanks Phelan! | ||
| Buell_bert |
I really do not think any flammable liquid should be used in a brake system, even to clean. | ||
| Greg_cifu |
What you have here is a problem with material compatibility. Rubber hoses and seals are not all created the same. Mixing the wrong materials will cause the hoses and seals to deteriorate, plug passages, leave residue in the reservoir and--yes--leak (eventually). In other words, the master, slave and hose should all be for the same type of fluid. Whatever that is, that's what you should use. If they don't match, now is not the time to cut corners. For the number of parted tubers out there, the correct used hose and caliper have to be available for around $50. I know this sounds preachy and idealistic but, I've tried to cut corners in the past and had it bite me. IMO: DOT 5 sucks. The stuff suspends air bubbles inside and doesn't release them until it gets hot. That makes the lever spongy until the gas has been cooked out and bled a couple of time. I can't tell you how many times my S2 has completely lost the rear brake because it got hot, the air bubbles came out of suspension and caused an air pocket. I've had the same problem with other bikes. My Excelsior Hendersons had a problem with clutch slave cylinders failing from the factory. Nobody knew why. They went through about two years of fiddling around before somebody discovered that the slave cylinder had the seal material chosen for DOT 4 fluid but, the bike used DOT 5. The DOT 5 was causing them to fail without warning. They changed the seal material and all the problems vanished. Dot 5 also doesn't absorb moisture. That doesn't mean you don't get moisture in your system. It just means that it doesn't combine with the brake fluid. So you end up with droplets of water, mixed in with your fluid. Those droplets don't necessarily come out when you flush the brakes. Dot 3, 4 and 5.1 fluids are all Glycol based. They don't have any of those negative tendencies. The only downside is that they eat paint. So what? Wash the area when you're done and the system is sealed. I still run DOT 5 in the systems that demand it but, IMO, it's a pain in the butt. If I could easily change those systems over to DOT 4 parts, I would in a heartbeat. | ||
| Jolly |
I searched on line (doesn't mean it's the best data)... Found a few references to using soap and water and also denatured alcohol to clean parts with to remove old fluid, so went with that. The hoses and caliper still had DOT 5, the only part that had DOT 4 was the master cylinder.... So cleaned the master cylinder then flushed by pulling 1/2 a bottle of DOT 5 through the entire system.... Full flush of old fluid. Let it sit an hour then test ride....,no issues, no leaks.... Going to let bike sit un-disturbed 1 week and re-test.... Lots of polar opposite opinions on benefits and preferences of DOT 4 vs DOT 5..... I don't race.... Just need good consistent brakes.... Thanks to all!!! I'll let you know if this ends up with issues! | ||
| Greg_cifu |
Well, I've gone full circle. I grew up with a friend's dad using DOT 5 in all of his hot rod builds (and he's well known in that world). It's got higher boiling temperature and doesn't damage paint. What's not to like, right? The boiling temperature is only half the story. The trapped air problem caused me all kinds of problems over the years. It was always a PITA to change out a bike. I finally learned it just wasn't worth it. Then they came out with DOT 5.1 which is glycol based but, matches the boiling point of DOT 5. No reason to aspire to the DOT 5 anymore. You made the same choice I would have. I run whatever the cap calls for now. I still hate the DOT 5. The S2 still loses the rear pedal on a long grade, despite numerous bleeds (each time, more bubbles come out). I've actually read about people pouring DOT 5 into a clean pan and heating it to 300-400 degrees and literally cooking it to get the air bubbles out. I've never tried it but, it might make life better. | ||
| Rocket_in_uk |
I've run DOT 5 in my S1W since new. I changed the master to an ISR several years ago. I have never had a single issue or problem with the brakes on my Buell in 16 years of ownership. DOT 5 works perfect for me. Rocket in England |
