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BE Hydraulic Question

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ralph_s

Jedi Trainee
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Finished installation of the new lines from Classic Tube on my BE. Took some "fiddling" to get them all in place. Ready to reinstall the fuel tank & rear axle and get a rolling chassis. (the front end conversion to disc brakes is complete).
I'd like to check my hydraulic lines for leaks prior to installing the engine & tranny. Can I plug the clutch side of the M/C and just bleed the brakes w/o and issue?? Never worked w/ a single M/C before and am not sure if this will be an issue.
 
Glad you got your lines in. Did you wind up with the steel or stainless lines?

I can't answer your leak question, but I'm curious as to the answer myself. I've got the same job ahead of me as well.
 
For the price difference I went w/ the SS lines. Probably an overkill, but should "impress" the next owner!!!!!
Had a situation w/ a new fuel tank I bought on ebay. Looked good, was made in Canada but didn't fit!! Had to fight w/ the seller to take it back, but did return although I'm still waiting for my credit!! Should have just stuck w/ the old one as it wasn't that bad......lesson learned!!
 
I'm at this point too, but was waiting to connect the clutch before bleeding. I see no reason why you couldn't plug the clutch output port on the master cylinder and then bleed the brakes. When removing the plug there might be some discharge (mess)before getting the clutch line connected. I was thinking that air might get in the lines and the brakes would need bleeding a second time. But, now that I'm thinking about it, as long as the clutch pedal is not pumped, there should be minimal discharge when the plug is removed and it shouldn't require bleeding the brakes again as long as the level of fluid in the master cylinder is not drained.

Try it and let me know how it goes. :yesnod:
 
That was my thought as long as I keep the clutch a closed system when bleeding the brakes. Hope to hear from some of the others for 2nd opinions, but plan to forge ahead in the next week or two. The good news is is I'm planning to "test" all my mechanicals prior to stripping it back down for body work, so other then a brake fluid mess... can't screw up much, but don't want to blow out something in the M/C.
 
I just did the same situation. I strongly urge you to go ahead and hook up the clutch line before you bleed the brake system. The reason for this is that there will be fluid at the clutch output port which will leak as you hook up the clutch line, if the clutch line is in then the fluid must travel uphill before it goes further and therefore cause no problem (won't leak). Just DON'T touch the clutch peddle before the tranny is in.
BillM
 
Bill,
Thanks for the feedback. Can I leave the clutch line open and not hooked up to the slave w/o any problems?
 
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?
Click to expand...


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.
 
I agree with Kellysguy about the moisture absorbtion- I deal with that by putting a plastic sandwich bag over the far end of the clutch tube and wrepping it with a rubber band to prevent moisture. The small amount of moist air in the tube I don't worry too much about.
BillM
 
Billm said:
I agree with Kellysguy about the moisture absorbtion- I deal with that by putting a plastic sandwich bag over the far end of the clutch tube and wrepping it with a rubber band to prevent moisture. The small amount of moist air in the tube I don't worry too much about.
BillM
Click to expand...

Luck you live in a really dry climate. Down here, you'd awake the next morning to a bag full of water! ( and maybe a crawfish or two in it as well) :banana:

The rubber bleeder nipple caps work well. (especially of of a VW bug)

Sometimes, if the m/c came with the push in plactis caps you can use thoses too depending on size.

I had a whole bunch of the rubber caps but they have all run away.
 
Thanks guys for the feedback, appreciate all the input. Open for me will be several months and living in PA our humidity can be an issue. Since this will be a new hydraulic system w/ lines, M/C, wheel cylinders & slave I might go w/ the DOT5 fluid. Need to do some more research on what the advantage/disadvantages will be.
ps I'm not concerned about crawfish getting in there, but more concerned about some small Amish guy crawling in there as I'm in the "PA Dutch" country.
Thanks again
 
If it doesn't use grass as fuel, it's "modern".

I can see where they might get confused hearing a rumor that the guy down the street had a Bug"E" in the gargae and not a Bug"I".
 
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