ralph_s said:
Bill,
Thanks for the feedback. Can I leave the clutch line open and not hooked up to the slave w/o any problems?
I planned on staying out of this one but I feel complelled to share some information seeing I don't know what your definition of "open" is, so I'll ad a little to what Bill said.
I'll share this and let you decide how it fits your situation.
The problem w/ DOT3 and DOT4 brake fluid is it's hydroscopic, meaning it readily absorbs water. If you take a container of NEW brake fluid, mark the level and leave it open for a period of time, you will see the level will rise.
This is moisture (water) that the fluid is absorbing. Depending on the climate, it can rise rather quickly. Down here by me it's a real problem. Water causes rust, rust causes problem.
This is why you can take a wheel cylinder apart that has had brake fluid in it for years and it be rusted solid......even though the system hasn't been left open. It''l draw in through the cap if given enough time.
The worst thing is, moisture causes a spongy pedal when it warms up AND, the water turns to steam durring hard braking causing serious brake fade (fluid above 212 degF, remeber steam is a gas which is compressable).
I'm not getting into DOT5(silicone) as you probably already have 3 or 4 in your wheels cylinders and you can't mix the two.
I am unfamiliar with the dual bore BE m/c, but if both clutch and brake bore share the same resevoir, the brake side will evenually pick up this contamination too (remeber osmosis).
All this being said, if it were me (which it isn't), I would bench bleed the m/c before installation (which you're supposed to do anyway), cap the clutch side off if you were to leave the slave off a while and install the line and slave later when you're ready.
I never install ANY m/c without bench bleeded as it makes the final bleed so much easier, the pedal better and you are assured of 100% air removal. Most of the time I can gravity bleed a system after a bench bled m/c swap without ever having to pump the pedal and it'll be ROCK hard with NO air in it.
Yes, fluid wil come out when you pull the plug. Just be carefull and place rags down and immeadialty clean up the fluid and use water as a final rinse if you spill any. You're taking a chance of spilling when you refill for a straight bleed anyway. ( don't use too much water as it'll come through the mount onto the floors.
If you don't care to go this route, I would at least put a rubber plug over the slave end of the line to keep moister out and those wonderful little wasps I have here that just LOVE filling small hoses and tubes with crap.
Once again, this all depends on "open" and for what lenth of time and climate.
I don't care where I am or how long it'll be, I only allow lines to be open for seconds. That's just me, I don't believe in taking chances. Your new m/c should have come with plastic plugs in it. They do this for a reason. Some (re)manufactures don't, but they'll come wrapped in a plastic bag. I turn down non-pluged "new" m/c's. It shows lack of commitment and an inferior product.
If you have some old brake fluid on the shelf, try a little experiment and see how long it takes to rise. (your supposed to not use old "shelf" fluid anyway for the above reasons. Yes, it will absorb water in the container AND brake system over time. This is also why you should purge brake systems on cars once a year that sit long periods.)
New fluid works better for the test but old (depending on how old) will do.
If you're using DOT5, moisture isn't a big concern, but those pesky wasps are !!!
Bill is correct, the brakes will work fine with the line off. It's how long you leave it off is where the problem comes in.