Actron Vacuum Pump Brake Bleeder Kit.

[kentuvman]

Many of you already know I picked up my '87 K75S that sat for a couple years. The brake fluid is dirty. I've already read a bunch of threads on bleeding non abs brake lines.

My way of thinking is the "old fashioned way" - connect tube from bleeder valve going into a container - opening fill cover - use a syringe to remove existing fluid in reservoir and gently squeeze brake lever continually until old fluid is pushed thru the line while pouring new fluid into reservoir. Helper by caliper watches hose until fluid is clear and while holding in the clutch handle tightens up the bleed screw.

I read the thread on the IBMR site and read the thread about using the actron pump.

Mine has double disc brakes in front so I'll do the one furthest from the reservoir first. What are the advantages of replacing brake lines with the braided s/s material and where do you get it if recommended? Is it going to be tricky getting front wheel back on and both discs lined up into calipers?

Finally, can I dispose of brake fluid with normal engine oil or does it require a special send-off to the waste facility in my city?

Thanks as always!

Ken

[Kayseventyfive]

Given that the front brake lines are mostly vertical, the tendency of bubbles to rise must be addressed. My own preference is to pressure bleed from the bottom up. Since you mention a helper, the helper can keep sucking out the reservoir until only clean, bubble-free fluid appears.

If I am bleeding the front without a helper, I use an oil squirt can with a hose and just wrap an old towel (large)around the reservoir to catch overflow as I watch it. It washes out well. Before I wrap the towel, I lay a large piece of plastic film over the reservoir and wrap it tightly with a rubber band around the reservoir. Then, I cut an opening over the mouth of the reservoir. That way, when the towel is wrapped around, no fluid sneaks down the side of the reservoir.

On other bikes, that were raced, and on when I worked in light aircraft, I have made reservoir fill caps that had a nipple for a clear hose to a container. It is efficient and sanitary, and looks trick. I just haven't done it yet for my K75, since it is not raced. I only bleed it after the rainy season.

If you suck from the bottom, or force fluid downward from the master cylinder, the flow must go downward faster than the bubbles can rise. This can be done by pressure bleeding with an adapter on the reservoir. If you are sucking from below, the nipples should be sealed to prevent air from sneaking in around the threads. I do not like pressure bleeding from above or suction bleeding with hand devices, as they have lapses in fluid movement as the piston in the pump is returned, giving bubbles time to hide and start to climb. A constant pressure or vacuum source works well, though. I bleed my tag axle motor home with a sucker that uses engine vacuum as it source. It is just a glass jar with one hose going from the lid to engine vacuum and another hose going from a dip tube through the lid to the brake nipple.


Finally, can I dispose of brake fluid with normal engine oil

No, it is a glycol and will contaminate engine oil and it will not be accepted for recycling.

does it require a special send-off to the waste facility in my city?



It will be up to your local hazmat authority, but many jurisdictions take it separately.

.

[kentuvman]

Thanks

[jcridge]

22 year old brake lines that have sat for a long period....? Yes replace them, no questions, just replace them. The lines tend to decompose inside and eventually plug either themselves of the orifices in the calipers. Speigler makes IMHO a great SS line kit for the K75's See thier website and give them a call, really good people. I have installed 2 of thier kits on K75's and they fit perfect. They carry a DOT stamp which depending on your state inspection process, may be required.

Bleeding the brakes old school works just fine, yeah it's it's slower...but are you in a hurry?

Power bleeding as kayseventyfive suggested is nice, not to mention very fast if you have the fixtures and pump.

Speed bleeders are another option, I can testify they work well in off road situations, but have not used them on MC's...yet.

[Beemer01]

Speed bleeders are great and make this a one person operation.

I do it annually.

[kentuvman]

Help me understand - to install speed bleeder, I first have to remove existing nipple. Won't all the fluid run out and put a lot more air in my lines?

Once installed, is the procedure to suck out the existing dirty oil with a baster and then start pouring down fresh oil and squeezing brake lever or pushing rear brake pedal until new clean fluid starts running out of bottom tube?

The other question was Kayseventyfive mentiones bleeding from bottom up - the vacuum units I've seen, they suck the fluid down - how to you push it up the lines and why is it considered "better" if you will?

[kentuvman]

Thank you for the Speigler source on where to find these!

[jcridge]

Help me understand - to install speed bleeder, I first have to remove existing nipple. Won't all the fluid run out and put a lot more air in my lines?

Once installed, is the procedure to suck out the existing dirty oil with a baster and then start pouring down fresh oil and squeezing brake lever or pushing rear brake pedal until new clean fluid starts running out of bottom tube?

The other question was Kayseventyfive mentiones bleeding from bottom up - the vacuum units I've seen, they suck the fluid down - how to you push it up the lines and why is it considered "better" if you will?

When you remove the stock bleeder screws there will be a small amount of fluid that will run out, remember this is a closed system so the fluid will not just gush out. You can install the speed bleeder quickly as they only need to be a hair past finger tight to bleed the system.

The fluid running out when you switch out the bleeders is fine, since you are bleeding from the top down the first thing that will happen is you will replace the trapped air with old fluid as it makes it way thru the system.

Follow the instructions with the speed bleeders if you use them, but it will be much the same as bleeding brakes normally.

If you replace the brake lines which I hope you do, you will be removing all the fluid first by opening all the bleeder screws with a clear hose attached to each nipple and dumping into a milk jug or pan that will hold all the fluid. Best way to do this is the night before you plan to replace the lines drain the system, let it drain all night. Put protection on anything that may come in contact with the brake fluid before you remove the lines. Always loosen both ends of the line first, remove bottom and place over a pan then remove top and let what fluid is left drip into pan.

The best way to do the rear line is to remove the right bracket with the master cylinder attached and finger tight the new line on the master cylinder first, then replace bracket and finger tight the line on the rear caliper. You will need to thread the rear line fitting thru the swing arm grommet, WD-40 helps it fit...it's tight. Then wrench fittings tight. Always finger tight fitting before wrenching...if you don't you'll know why.

The front lines are straight forward nothing special to note. I believe the end fittings on the line from the Y to the front master cylinder have different angles, just compare to the old line your taking off.

[mrich12000]

This is an ez home made device to bleed your brakes . it uses a windshield wiper pump and related 1/8 clear hoses and wiring up the pump using alligator clips for battery connections. NAPPA should have one @10.00 and the hoses as well. use it to suck the fluid out of the bleeders . Works great for me. Make sure the brake pads are in good shape ,and in dought replace the full set @120.00 N Ebay..

try it .. Caution use only DOT 4 don't use silicon ...

[Kayseventyfive]

Help me understand - to install speed bleeder, I first have to remove existing nipple. Won't all the fluid run out and put a lot more air in my lines?

It depends on how fast you stick in the Speedbleeder. Also, leaving the cap tight on the reservoir slows down the runout.


The other question was Kayseventyfive mentions bleeding from bottom up - the vacuum units I've seen, they suck the fluid down - how to you push it up the lines

I use an oil can with a trigger pump or a modified Hudson sprayer. One place I worked had a special tank that was pressurized with dried shop air and carried out to the plane.


and why is it considered "better" if you will?

I prefer it because the air bubbles want to rise naturally, and bleeding downward goes against this. Between strokes, the air stops moving, and even starts to go back upward. With pressure bleeding upward, the flow of fluid and the natural upward flow of air work together.

However, it you have a constant pressure source, bleeding downward is good. I have reservoir lid adapters for several of my vehicles, and use dried regulated shop air or even a modified Hudson sprayer to force fluid downward with great success.

So, even though I don't think I said better, "better" is not necessarily an outright truth, just a preference, and for me, applies only when a constant pressure or vacuum source is not available.

[mieczkow]

I have used all manner of tools to bleed brakes, from the twist open the bleed screw/twist close (a helper pumps the brake if you can't reach it), speed bleeders (very nice), a cheap but effective check valve that will work with any sort of brake nipple (think of a speed bleeder which you can just clip on to any bleed nipple), and a very nice pro-grade Mit-y-Vac.

In all honesty I have never had a problem bleeding brakes using any of these, though speed bleeders seem the best deal for the price. A couple of thoughts:

1. With hydraulic systems if you pump enough you will pump out any air unless you have a leak. I wouldn't sweat the position of the reservoir, etc. Just keep fluid in the reservoir, keep pumping with a check valve or speed bleeder and all the air will come out. If not, it is very likely that something is wrong with the piston, piston o-rings, or the bore of the cylinder. The stroke volume on a motorcycle master cylinder is small. Keep pumping.

2. As far as worrying about pumping out and/or using a vacuum or pressure system to suck out the brake fluid - don't worry about it. Brake systems are closed, and will rarely get dirty enough to worry about under normal conditions and with normal, sane maintenance. If you have so much dirt and gunk in your brake reservoir and/or brake lines that you are worried about pulling it through the system with a vacuum (or pressure-driven for that matter) pump, you better (a) buy new lines, and totally disassemble your system and clean the crap out of it and (b) start keeping your bike a little cleaner, especially if you have the habit of frequently unscrewing the reservoir cap and dumping dirt into it.

While break fluid can collect moisture and impurities, you have to be pretty sloppy or unlucky to get lots of solid particulate in the system. That might happen if your bike is so old that lines or o-rings are deterioring and crumbling. But most BMW folks take better care of their bikes. I think dirt mainly becomes an issue if buying something that has stood still for a long, long time - to the point where the materials themselves are deteriorating. Typically these bikes have all sorts of fluid problems (gas tanks, oil passages, etc.) in addition to the brake system.

Get some speed bleeders, a little hose to go into a jar to catch the outflow, a can of brake fluid, use common sense and the chances of a brake bled job going south is pretty slim.

:gerg

[kentuvman]

I did it the old fashioned way - tube, jar, open bleed valve -squeeze brake - close brake valve . . . got it done okay. Believe I did it right.
Will buy speed bleeders for next service.
Thanks for all your comments. A lot of great perspective on how to bleed systems.

Ken