| Author | Message | ||
     Tazmania720 |
I think I need to rebuild the rear master cylinder on my bike. I am trying to locate the gaskets that go in there but I was wondering something, does the material type matter? I know DOT5 is silicone based, so I was not sure if the gasket material needed to be specific. Any info would be great. | ||
| Buell_bert |
I have used DOT5 in my Harleys but Buell specifies DOT4 so thats what I would use with their gaskets. I think it maybe a heat issue. | ||
| Kilroy |
I think they switched from DOT5 to DOT4 in the 2000 model year (or vice versa) | ||
| Bluzm2 |
Taz, the cover should tell yo which fluid to use. You can order rebuild kits for the master cylinder from your Buell dealer or any of the sponsers here on BWB. Brad | ||
| Buell_bert |
Are you thinking of going over to DOT 5 instead of using DOT 4??? | ||
| Tazmania720 |
I have a 99 and the cover says DOT5 and I am using it. What I am asking is I remember reading/hearing something about how DOT5 reacts differently to different types of rubber, making the gaskets break down faster. I am having a problem with my rear master not building up pressure and I was wanting to rebuild it. I know there are U-cups in there and wanted to make sure if there was a special type of rubber I needed to buy. | ||
| Kusskid76 |
Here's the skinny on Dot 3&4 vs Dot 5. Dot 3&4 are glycol based fluids and they work well but glycol absorbs moister out of the enviornment mostly from condensation from the heating and cooling of the brakes thus causing a build up of water in the brake system that reduces the effect of the brakes and corrosion in the entire brake system if you don't flush it regularlly. So Dot 5 was developed by or for the military because the always crossing rivers and such and had lots of problems with water so Dot 5 is silicone based and will not absorb water and wont eat paint like Dot 3&4. However water still gets in to Dot 5 braking systems and because Dot 5 dosen't absorb water and water is heavier than the brake fluid the water sits at the lowest point in you your braking system like your nice aluminum calipers so it is very important that you flush Dot 5 fluid. I don't know if there's a difference in the rubber used between Dot 4 and Dot 5 systems but I wouldn't take the chance of finding out the hard way. Like Blumz said you can order a rebuild kit or a new master cylinder which I had to rebuild the front and replace the rear on my 98' S1. If your X1 rear brake set up is like my 98 S1' take your rear caliper off and hang it with some wire or something to make it the highest point in the system it will make it way easier to bleed. Hope this helped good luck | ||
| Buell_bert |
The Buell part # for the 2000-2001 M2 rear caliper repair kit is 44149-98y and that uses DOT 4. Is the 98-99 kit the same part #. If so the type of fluid is a moot point. I guess I would use what is specified on the cover. I have used DOT 5 in the past and had no problem at all. And it does not eat paint which is a plus. |
