| Author | Message | ||
     Austexs3 |
I bought a used 2000 S3 in December, my rear brake quit working, caliper piston is barely moving. I checked the oil level in the rear reservoir and the black cap said use Dot 5, It appears that there was Dot 4 in it? I ordered a used caliper, lines and reservoir off Ebay. Seller said it was off a 2000 S3, but the reservoir cap says use Dot 4? What do yall think? Did using Dot 4 kill my rear brake? | ||
| Hootowl |
To the best of my knowledge, 1999 S3s use DOT5 and 2000+ S3s use DOT4. | ||
| Blackm2 |
Using DOT 5 in a DOT 3 or DOT 4 system without proper flushing will cause damage to the seals and cause brake failure. I believe the reverse is true also. | ||
| Littlebuggles |
I've read here that you should flush with alcohol, thoroughly, then run the Dot 4, and use the correct cap, so you know what you've got in there. Check the front brake res, make your fluids match as they would have from the factory, so if for some reason your Y2K bike is running DOT5, it will have it up front too. For reference, my Y2K Cyclone M2 runs DOT4. | ||
| Pkforbes87 |
Isn't there a DOT5.1 that has the high boiling point of DOT5, but is compatible with 3 and 4 ? | ||
| Skntpig |
DO NOT USE THOSE PARTS TOGETHER. Sounds like the Dot4 killed it. If you have ever used Dot5 in a Dot4 or vice versa do not use the part you put the wrong fluid in. Do not use the line that had the wrong fluid. 3 and 4 are cross/mixable but 5 can only be used with 5. To confuse you they now have 5.1 that will only mix with 3+4 but Not 5. IIRC older bikes used 5, newer used 4 but I could be wrong. All the rubber will swell or contract using the wrong fluid. All the seals need to be replaced and All the fluid flushed with denatured alcohol, dried, flushed with correct fluid, flushed and dried and bled with correct fluid. I googled the issue and found this, a pretty straight forward response. http://www.tccoa.com/brake-fluid/ If you want High boiling point Dot4, I have had great luck in race bikes and track driven cars with Motul RBF600. There is also Motul RBF660 but hold your wallet. As you can see below 5.1 isn't always superior to 4. See Motul. http://members.rennlist.org/911pcars/brakefluid.ht m Please don't rely on my info, do your own research before making a dangerous mistake. | ||
| Pash |
All my Buells run DOT 5.1. You can do a search on Google as to compatibility and you can find those that say it is compatible and those that say it isn't. Here is one that tells you that you can mix them (but they will stay seperated) - http://importnut.net/brakefluid.htm I cannot fathom why, when mixed together, they will mess up your seals. Seals tend to swell and perish when you expose them to petroleum based fluids. I should add that the systems I use DOT5.1 in, that were intended for DOT5, were stripped, cleaned and regreased (with Castrol red or silicon grease) before the change in fluid. | ||
| Nitrous_jim |
all you have to do is flush all the dot 5 out and replace with dot 4 and your rear brakes will magically start working. it took me no less than six hours to figure this out. dont let my effort go to waist. try it. (Message edited by nitrous_jim on February 19, 2013) |
