I'm going to run a steel line from my rear brake line on the bike to the sidecar brake. after the tee I was thinking about installing a small high pressure valve in case it has to be removed for servicing or repair......Ever seen that before?
Quick disconnect fittings are easily available for this purpose.
Lonnie
Also the Mico style line lock will block flow, switch on or off. There are much less expensive versions of Mico line locks available on VW Dunebuggy parts sites in the $30-$40 range. Nice thing about line locks are they'll work for what you describe but they also work great for a parking brake. If you hit your pedal first before engaging lock valve the brake pressure is maintained until you release it. With a little applied cleverness on where it's installed it can also help as an anti theft device.
Most likely a standard 1/4" brass ball valve would work just fine for doing service work, of course still requiring a bleeding after the valve, between it and the serviced parts.
Remember that all brake lines are a double flare type requiring a double flaring tool, not a standard single flare as found on fuel, oil and pneumatic lines.
I don't know what pressures can be generated in the master cylinder for the rear brake on a motorcycle, but if it is as high as in a car's brake system you could see 1000 psi and you would not want to put any valve in the system that was not designed especially for a brake system.
The Mico brake locks are specifically designed for vehicle hydraulic brake systems, and widely used throughout the industry for many years on heavy equipment and trucks. A Yahoo Search - Mico brake lock - will return lots of informative websites.
Other players in the aftermarket also manufacture brake locks, also called hydraulic line locks, and much less expensive than Mico. As mentioned they're commonly used on dune buggies, race cars and off road brake systems.
http://www.jegs.com/p/JEGS-Performance-Products/JEGS-Hydraulic-Brake-Lock/1769685/10002/-1
My reference to a standard 1/4" brass ball valve is that it would most likely be suitable for service work. In that use there would be no high pressures, with no pressure applied at all. Instead it's just used to prevent air from entering system when parts are disassembled. I'd guess one could also be used as a parking brake, even if it didn't hold absolute full pressure. It's not used in the system for general braking, but just for maintaining pressure on brake cylinders to prevent vehicle from moving.
Normal working pressures for brass ball valves are 500-600 psi continuous. Hersh Parker carbon steel or stainless ball valves have much higher working pressures, up to 1,500-2,000 psi.
http://www.nibco.com/Valves/Ball-Valves/Brass-Ball-Valves/
http://www.pexuniverse.com/store/category/sweat-ball-valves-c-x-c
http://www.hershpacking.com/Ball%20Valves.html
I fully agree that safety comes first, especially in any vehicle brake system!
"Most likely a standard 1/4" brass ball valve would work just fine for doing service work, of course still requiring a bleeding after the valve, between it and the serviced parts."
My comment was only directed at the reference to the brass ball valve. The line locks etc are designed for braking systems and are compatiable with brake fluid and capable of pressures several times the maximum brake pressre (but one would still want to read the instructions to make sure it can be used with the brake fluid required by the bike manufacture). Acually I see disconnecting the hack as a good opportunity to flush out the old brake fluid and replace it. When I installed my sidecar late this summer the system bleed out in just a few minutes with no problems.
Many use the quick disconnect fittings thinking they will never have to bleed the system. It doesn't always work that way. They may still allow a small amount of air into the system. For some systems the air will migrate back into the brake reservoir, others will keep the air trapped in the system affecting brake effectiveness.
I always bleed the system after an R&R, even those with quick disconnect fittings. It eliminates the "What if ?" factor.
Lonnie
Northwest Sidecars
Markh00 - 12/25/2012 7:31 AM
"Most likely a standard 1/4" brass ball valve would work just fine for doing service work, of course still requiring a bleeding after the valve, between it and the serviced parts."
My comment was only directed at the reference to the brass ball valve. The line locks etc are designed for braking systems and are compatiable with brake fluid and capable of pressures several times the maximum brake pressre (but one would still want to read the instructions to make sure it can be used with the brake fluid required by the bike manufacture). Acually I see disconnecting the hack as a good opportunity to flush out the old brake fluid and replace it. When I installed my sidecar late this summer the system bleed out in just a few minutes with no problems.
Yes, Mark, and I agree! I simply meant to post some extra info but somehow it came out sorta smarmy sounding, which wasn't intended. Sorry about that.
One of the world's great tools is a 'one man brake bleeder'! You can buy them, but I make my own out of a little relish or jelly jar. Get a couple of feet of rubber tubing in a size that fits real tight over the brake bleeder. Poke a hole in the jar's metal lid, just big enough for tubing to fit through, add about 1" of brake fluid to jar. With end of tube under the fluid in jar, shove the other end tight over the brake bleeder on caliper or cylinder.
Crack bleeder and pump the brakes a few times. Some surprisingly nasty dark fluid will pump out and so will all the air. Keep a close watch on master cylinder to keep fluid level up as it drains through lines. Tube under fluid in jar prevents air from being reintroduced into system.
On some systems no pumping is required as fluid will bleed to jar by gravity. Either way it takes a lot of work out of the job and makes it a one man operation!
.
Help full discussion, I have a oilfield instrument shop just up the road that has high pressure stainless tubing and valves in all sizes.......I'm going to get what I need from them.......
You might want to look at Spiegler brakes' web site. They have quick disconnects but they're not cheap.
Lonnie, can you give me a description of parts I need to hook up "quick disconnect" for my Liberty sidecar brake system. Do you have to change the rear brake banjo fitting? Do you stock these connections? Thanks
I don't use a quick disconnect on mine as I've found I've still needed to bleed air even with the quick fittings.
Lonnie
We stock quick disconects that are set up with 1/8 inch pipe threads. We can also set them up with braided line. I find that they work great, the trick to using them and not getting air in the system is to turn the female end up right. Take a screwdriver and depress the check ball long enough for a drop of fluid to form, then conect it. The drop of fluid keeps that air from getting in. If you do not do this about every 4 or 5 times you hook up the brake you will need to bleed it. Still better then having to bleed it every time.
Jay G
DMC sidecars
www.dmcsidecars.com
866-638-1793
jay@dmcsidecars.com
