DOT 5 brake fluid

I'm more of a reader than a poster but I need some expert advice. I recently added a 77gl1000 to my motorcycle inventory.
The bike is in original condition. A 7-8 on a scale of 10. 18000 original miles. PO seemed to be knowledgeable on maintenance and actually built many types of bikes over the years, including race bikes. Everything on the bike works, belts have been changed, tires are less than two years old, etc. The one thing I am worried about is he changed the brake fluid to DOT 5. He flushed the system by sucking the new fluid through. I did research an article on this site that said once you have changed, don't try to go back. I don't know how much he flushed the system. What am I in for. This bike is in no way going to be ridden more than it needs to be and I am a stickler for keeping things original. Any suggestions, comments would be welcome.

I believe that DOT4 is compatible with all the versions before. DOT 5 as I understand it is not. That said I don't believe the brake lines have changed between the versions of fluids. If he was as knowledgeable and competent as you say I'd not worry too much. Just watch for leaks and spongy brakes. If you do need brake fluid do not use anything other than DOT 5. If brakes leak or get spongy you probably want to rebuild the ca;lipers and masters replace the brake lines and flush both systems befor going back to DOT 3 or 4 fluids.

i am not sure but i think the reason to go to dot 5 is ...on a bike like yours the dot 5 fluid is less corrosive and not a threat to paint and plastic on a original bike like yours ...

Here's some info on the brake fluid. Personally I use DOT 4 since I would rather have the fluid absorb the water and then change the fluid periodically than to have the water form globules and settle in unreachable places that you can't get to without disassembly. https://www.xs11.com/xs11-info/tech-tips ... versy.html

All good points and yes, the reason he changed to DOT 5 was the fact it is not harmful to paint. I'm just not sure you can flush a system good enough without disassembly to use two noncompatible fluids. Seems there is always some residue left somewhere depending on how many times you do it. How much moisture will get into the system if it is used rarely and stored inside I don't know. I do believe I will just keep an eye on it and see what happens.
I was hoping someone on here may have done this and the results. The back wheel caliper hangs up a bit but could be as simple as a piston needed to be used a little more. It does release if you run it through the gears. This is what started me thinking. No trouble with the fronts at all.

[url=https://www.classicgoldwings.com/forum/viewtopic.php?p=137656#p137656:355jmd3j said:

backlander » Thu Dec 18, 2014 10:43 pm[/url]":355jmd3j]
Here's some info on the brake fluid. Personally I use DOT 4 since I would rather have the fluid absorb the water and then change the fluid periodically than to have the water form globules and settle in unreachable places that you can't get to without disassembly. https://www.xs11.com/xs11-info/tech-tips ... versy.html

Click to expand...

+1 :yes: :moped: :good: