|
|
|
going to dot3 from dot5
- Thread starter kellen
- Start date
Without sounding a smarty pants I really would refer to the manufacturers websites. If they don't give an answer then get in contact with their tech support. Brakes aren'ty something we want to be second guessing about.
I recently started using 5.1, although I was rebuilding my calipers and installing a new master, new reservoir and fitting new braided lines at the same time so really didn't have to worry.
I recently started using 5.1, although I was rebuilding my calipers and installing a new master, new reservoir and fitting new braided lines at the same time so really didn't have to worry.
So I got a little curious and did some research. This part stood out to me.
Dot 3 being glycol
Dot 5 being silicone
"On the practical side, beware that glycol and silicone brake fluids are hugely incompatible with each other. Mixing even small amounts will create a sludge that looks amazingly like Italian salad dressing and is about as effective as a brake fluid -- meaning, not. Of further consideration is that, in some cases, the hardware designed for one fluid will not accept the other. Brake caliper and master cylinder seals, hoses, and other parts won't always work correctly when the type of fluid is changed."
Source: http://www.motorcycleproject.com/motorcycle/text/cows-brakefluid.html
Dot 3 being glycol
Dot 5 being silicone
"On the practical side, beware that glycol and silicone brake fluids are hugely incompatible with each other. Mixing even small amounts will create a sludge that looks amazingly like Italian salad dressing and is about as effective as a brake fluid -- meaning, not. Of further consideration is that, in some cases, the hardware designed for one fluid will not accept the other. Brake caliper and master cylinder seals, hoses, and other parts won't always work correctly when the type of fluid is changed."
Source: http://www.motorcycleproject.com/motorcycle/text/cows-brakefluid.html
This is good advice, I heard the same thing about seals. Probably means you need to do some research on your parts.
Or you can just forget you posted this thread and fill the brake system with dish soap.
I totally agree. Previous owner ran dot5 unfortunately and I have no experience with it.
This is not a black art.
DOT 3, 4, and 5.1 are all compatible with each other.
DOT 5 is not compatible with any of the above.
Switching from one type to the other requires a complete clean & rebuild of the system. Worst case scenario - your calipers fill with goo and suddenly don't work so hot.
If the OP plans to continue using this as a racebike, you're better off to continue using DOT 5. It's not so great for street use as water can collect in the bottom of the system. It is however legal, and some Harleys came with it from the factory.
I didn't say it was a black art. I suggested he get advice from the manufacturers rather than from an internet forum, simply because brakes are crucial bits of equipment. And that was just my view, not the definitive answer. And even though you sound extremely well educated regarding the subject, even if I knew you and you were stood in my garage advising me, i'd still sneak off and check with the manufacturers.
If ti has 5 now I would just stay with 5.
U should switch to Dot 4 if u are switching. It has a higher boiling point. Dot 3 is old tech.
U can mix dot 3 & 4. Just flush it, not a complete mix
Last edited:
mma01
Well-known member
I can think of once instance where I would use DOT 3 over DOT 4. Ford HD DOT 3 is an inexpensive brake fluid that has a higher dry boiling point (550 degrees F) than most DOT 4 fluids, *BUT* it has worse a wet boiling point, which leads to its DOT 3 classification. If you change it frequently, its a great track day brake fluid.
I've heard DOT 4 absorbs moisture less readily
mma01
Well-known member
For a track bike that has fluid changed often (i.e. before every event in some cases), this is less of a concern.
See that is the kicker, the master you want to use was used with DOT3, but caliper and lines you want to put it on were used with DOT5... So either you are converting the calipers and lines or you are converting the master... either way...
Easiest path to me is just don't switch the master (is your's dead)?
|
|
|
|
|