What size tubing to bleed brakes

Can somebody tell us what size the transparent hose should be in a perfect world to bleed the 2004 650's brakes-? I believe it's the same size nipple for the 1000 but not positive: also for all the years-?
A bonus would surely be where to buy this clear hose other than a hardware or auto parts store. I was thinking online ...

The last couple times I bled I saw air slipping in due to my not perfect fit for the hose. I tried a small hose clamp but it kept slipping off ... it seemed to be at the end of a lever squeeze. At first I thought it was air in the line but realized it must have been the connection and ignored it.

In the end all was fine but I sure would love to know what size hose I should use for that perfect world fit ...

Thanks-!

Checked the bleed screws on my Vee. 7mm is the head size.
This is also the size of the Nissin 4 piston calipers I just installed.
With 6mm pretty close to 1/4 I would look for some tubing with an inside diameter of that, or a bit smaller.
I use the Might Vac system to bleed the brakes that pulls the fluid from the bleed screw.
One trick I learned is to put a little silicon grease around the base of the bleed screw threads and the tubing joint to prevent air from being drawn in past the threads when bleeding and appearing that there's still air in the system.
I just got a few various sizes of vinyl tubing in short lengths. The stuff I got came from the local hardware store and seems to be fine with brake fluid and fits most vehicles.
Bernie 05-DL-1K

yes-

Yesss, thank you Bernie -- excellent idea about the silicone or grease on the tube and fitting. I suppose just a wee bit wouldn't get into the system. Not sure if it would even be a bad thing-??

I tried buying three sizes at the local auto store and no luck. One was just the wrong size and brittle. Most of what they had was black, for windshield washers they said. I'll try our bigger hardware store, I just hate going there.

Thanks again B,
-Dan

Wrap teflon tape around the threads of the bleeder to prevent the air leaks.

The silicone grease could get sucked in and contaminate the brake system. Not what I would use.

As far as the tubing, 1/4" usually works -- some types or brands of tubing are slightly tighter or looser, though. I've also found that most types of clear or translucent tubing will eventually deteriorate from exposure to brake fluid, but tubing is cheap, and being able to see the bubbles is crucial.

Any real hardware store (like Ace or Do it Best) will have clear vinyl tubing for less than a buck a foot (Hint: Meantard's, bLowes, and Home Despot are not real hardware stores.).

Have also used the teflon tape with mixed results. It does work if your carefull.
I just didn't like the possibility of the tape showing when done.
The silicone grease applied on the outside of the bleed screw seems to be heavy enough to not be pulled down the threads and if it did it would be pulled out through the bleed screw. Because none of us reuse the fluid once its been removed from the caliper right?
Just seems to act as a temporary seal that you wipe off when your done.
Both seem to work fine, take your choice.
Bernie 05-DL-1K

Thanks you guys. 6mm or 1/4" ID seems right. I think the teflon tape carefully if I had to as I think about it.

I am going to find the exact size if I can and buy 10 feet and that should last for awhile. Maybe 20 feet, should last for at least 10 fluid changes or aprox. 20 years-! :auto: I'm off to find it soon ...

Found 1/4 ID heavy walled clear tubing at a local non chain auto store next town over. He only had six feet and I took it. I did a dry fit and seems perfect. I realized the nub on the end of the bleed valve it quite short so maybe thats part of the trouble-?
Perhaps other bleed valves have a bigger nub. I'll have to look at some of the pic here. As far as I know mine are stock for the K4. Just can't seem to spend money on the speed valves.

Well it should be awhile until I need to change the fluid again .....

Thanks to you that answered for your valuable ideas-!!

So 6mm ID would be good enough.

Does anyone know if the brake bleeding valve is the same size as the nozzles for the throttle body adjustment?

I'm going to do a brake flush and I have about 20ft of leftover vinyl transparent hose from the TB work some time ago so I wonder if it would fit snug enough at the brake bleeding nozzle. I don't remember what size hose I bought for the TBS

The vacuum ports are smaller than the brake nipples. 4mm is the ID on OEM vacuum hoses and 5/32 is about the same size. Some people like 1/8" for a tighter fit.

Thanks guys. Used the last of my clear hose when I did the front line change over a couple of weeks ago. I have forgotten what size I used the last time I bought some. This makes it easy. I will pick up some for vacuum at the same time. Then I will have the proper sizes in the shop ready for the next time I need some.