Getting brake fluid into an empty system

[Joe Nardy]

I'm getting ready to install stainless brake lines on the front and rear of my 83 GS1100E. While doing so I plan to drain the system completely. What is the best way to get fresh fluid through the entire system and bleed the lines? (I don't have a power bleeder.) Also, what brake fluid can I use? I have some DOT4 synthetic I'd like to use but I want to make sure it won't cause problems.

Thanks for all suggestions,
Joe

[gsbill]

One way is to pump the fluid up from the bottom...Another is to pour it in and bleed, bleed, bleed...You can use one of those oil cans with a little pump handel on it...be sure its spanky clean before ya start...Have lotsa fluid handy before you start..not sure on the fluid type...check with your dealer...I always thought you could have one or the other, but do not mix fluid types...Its quicker to have a helper when you bleed brakes.

[fastpakr]

DOT 3 and 4 can be mixed with each other, but 5 is a whole different matter. It's no big deal to start with an empty system, just have a helper and be prepared for it to take a few minutes.

[Anonymous]

The only difference between DOT 3 and 4 is the boiling point of the fluid. They are both mineral based fluids, so they can be mixed together. The only thing that mixing them together does is change the boiling point. Example Putting 4 into 3 raises the boiling point of the 3. Putting 3 into 4 lowers the boiling point of the 4.

Dot 5 is a synthetic fluid, and can only be put into a system made to handle DOT 5. DOT 5 swells the rubber of a DOT 3 or 4 system, and then you will have to replace every rubber component in that fluid circuit. Its lots of fun, I love when that happens at work!! $$

I have never heard of, or seen, a synthetic DOT 3 or 4, so be careful. :twisted:

[KEITH KRAUSE]

I've used Dot 5 silicone in my '79 GS1000E for 25 years. The original Dot 3 was only in it a week. Did a complete teardown, even the calipers taken apart to flush all traces of Dot 3 out. Never had a problem yet. Never attracted a drop of water.

[Hotblack]

I don't get what's so hard about bleeding brakes on a bike? I have a little plastic bleeder cup I bought in an auto parts store to do cars (makes it pretty easy) and on the bikes you can even pump the lever/pedal and turn the bleeder nipple at the same time. Seems easy as pie to me. Yet I see people selling $200 bleeding systems and stuff like that.

[AOD]

I have a little plastic bleeder cup I bought in an auto parts store to do cars

i too bought something like that from Sears. you just open the bleeder nipple and start pumping until all the air is gone. shut the bleeder and go on your way!

~Adam

[Planecrazy]

I'm glad for the clarification regarding DOT 3 vs. DOT 4. I noticed on my 550's tank that either 3 or 4 was acceptable. Just changed the pads and am about to completely replace the old fluid...

Steve 8)

[Mr. Jiggles]

When I installed SS lines I picked up one of those bulb siphons and, like gsbill said, filled it from the bottom (from the anti-dive units). All in all it seemed like there was less bleeding involved.

Good luck, Joe.

Jeff

[saaz]

Also remember there is DOT 5 silicone and DOT 5.1 mineral based brake fluids, just to be confusing....

I used synthetic for many years also, now use normal fluid changed every year. Braided lines make more difference, and modern mineral fluid are far better than they used to be in terms of boiling point.

[ZacharyB]

I just put fluid into a completely empty system. What I learned was that the master cylinder will make an equal amount of vacuum as it does pressure with each lever pull. Therefore, I stood with a plastic 1/4" tube from the bleed nipple to a jar of brake fluid, watching the fluid go up and down, up and down, up and down in the tube with each squeeze. There is no vacuum in the line because the master cylinder is a two-way valve (if your relief hole isn't clogged!)

What I ended up doing is borrowing my dad's industrial suction hand pump and buying a threaded fitting for it that allowed for attaching a plastic tube. Then I connected it to the bleed nipple, opened, and pumped away, creating a vacuum that ssssssssuuccked the brake fluid all the way through the line. The pump was a one way valve like all pumps (of course).