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Discussion Starter #21
so the accumulator isn't necessary? what happens if you do an emergency stop pushing the clutch and brake at the same time?
The main purpose of accumulator is to hold vacuum while engine is turned off. . . . So prior to starting, the clutch is easy to push down that first time.

During an emergency, the engine would provide plenty of vacuum (unless the clutch, brake, AND throttle are all down at same time :D)
 

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i guess my thing is that i've had the check valve in the brake booster fail on me before. normal driving, it was fine, but coming off a boost run and braking, there was still pressure in the lines and it felt like i was pushing against a brick wall. the pedal wouldn't budge at all. i guess if the check valve holds when you push the clutch and brake, it would be a good way to remove clutter from the engine bay. i know i hated that hardline and bought Jack Hammer's silicone replacement for it. basically, silicone lines with a check valve in it.
 

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Interesting idea Ron! I have the 'monochrome' method of vac. reduction, so in my car instead of looping the clutch vac. assist into the brake booster, the brake booster is looped into itself with the clutch assist line going to the plenum nipple right after the TB. They're so similar, maybe I'll try it out your way. :p :cool:

--Ryan
 

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Discussion Starter #24
i guess my thing is that i've had the check valve in the brake booster fail on me before. normal driving, it was fine, but coming off a boost run and braking, there was still pressure in the lines and it felt like i was pushing against a brick wall. the pedal wouldn't budge at all. i guess if the check valve holds when you push the clutch and brake, it would be a good way to remove clutter from the engine bay. i know i hated that hardline and bought Jack Hammer's silicone replacement for it. basically, silicone lines with a check valve in it.
Boost pressure where there should be vacuum would be a scary thing!! :eek: In the way mine it connected now though (no accumulator, and very short lines), it would seem that boost in the brake and clutch boosters would not last long. As soon as the throttle plate shut, it would be quick vacuum.

Interesting idea Ron! I have the 'monochrome' method of vac. reduction, so in my car instead of looping the clutch vac. assist into the brake booster, the brake booster is looped into itself with the clutch assist line going to the plenum nipple right after the TB. They're so similar, maybe I'll try it out your way. :p :cool:

--Ryan
I was not aware of the 'monochrome' method, when I stumbled onto this method. . . . I am still trying to envision what it is. "brake booster is looped into itself" is throwing me. . . . I could see where vacuum source might be the nipple after throttle body, via checkvalve hose to a 'cut' clutch assist line, then a hose from clutch line "T" to brake booster. The stock hose would be too short though, right?

If you have already done it that way, I am not sure there is any advantage to changing, unless a clean firewall is desireable. If starting from scratch though, I can not imagine anything simpler than what I have done. No new parts, just a cut and bend (and remove everything else left over)
 

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now that i know the accumulator isn't necessary, i'll just run a straight silicone line with a check valve in there to the booster. thanks!
 

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I was not aware of the 'monochrome' method, when I stumbled onto this method. . . . I am still trying to envision what it is. "brake booster is looped into itself" is throwing me. . . . I could see where vacuum source might be the nipple after throttle body, via checkvalve hose to a 'cut' clutch assist line, then a hose from clutch line "T" to brake booster. The stock hose would be too short though, right?

If you have already done it that way, I am not sure there is any advantage to changing, unless a clean firewall is desireable. If starting from scratch though, I can not imagine anything simpler than what I have done. No new parts, just a cut and bend (and remove everything else left over)
I'll try to snap pics tomorrow!
 

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so the accumulator isn't necessary? what happens if you do an emergency stop pushing the clutch and brake at the same time?
I did this a couple weeks ago and haven't had any issues ... or a chance to take pics. :eek: I also did it without any benders, just a hand saw, and a new short piece of hose ($2 maybe?).
 

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I did this a couple weeks ago and haven't had any issues ... or a chance to take pics. :eek: I also did it without any benders, just a hand saw, and a new short piece of hose ($2 maybe?).
i can't tell from your pic, is your car turbo? have you tried an emergency stop yet?
 

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an even easier way to do it is to use the hose with the check-valve to come off the manifold nipple. I then have a plastic T the hardware store that splits off into the clutch booster and brake booster.

Then you can get rid of ALL of that garbage along the firewall.
 
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i've never run the vaccuum tanks. There are useless except on intial start. Disabling the clutch safety fixes that.
 

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so what is the exact purpose of doing this vac reduction? What will you gain from doing it? I'm not questioning your work, just curious as to if i do it on my car what i'm gaining lol
 

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so what is the exact purpose of doing this vac reduction? What will you gain from doing it? I'm not questioning your work, just curious as to if i do it on my car what i'm gaining lol
Less junk/dead weight in the engine bay. Basically less weight and easier to work on/easier on the eyes.
 

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Discussion Starter #34 (Edited)
so what is the exact purpose of doing this vac reduction? What will you gain from doing it? I'm not questioning your work, just curious as to if i do it on my car what i'm gaining lol
Less junk/dead weight in the engine bay. Basically less weight and easier to work on/easier on the eyes.
^^^ a good short answer.

A more detailed one:

There are two "boosters" on the driver-side firewall. These use vacuum to assist the driver in depressing pedals.

1) A brake booster that gets its vacuum source from a nipple on the intake plenum, just after the throttle body. There is a checkvalve in the first rubber hose that will allow the engine to create a vacuum in the brake booster housing (but prevent the flow of air into the booster if the throttle is opened). The route is --> rubber hose at intake, to hard-line attached to firewall, to short rubber hose that connects to booster.

2) the clutch booster gets its vacuum source from a nipple on the intake on the driver's side. It also has a checkvalve in the rubber line. Its route is --> rubber hose at intake, hard-line that runs behind brake booster, this hard-line then has a hidden "T", one side runs to driver-side clutch booster. The other side runs across the firewall, past the battery, down under the fuse box area to two big tubes attached to the frame. These are accumulators that "store" vacuum, so that when the engine is shut off, it is easier to push the clutch pedal. :rolleyes:

There are several different ways to eliminate all this "needless" plumbing. I only have time to describe two at the moment:

In both of these, all of the hard-lines that run across the firewall, past the battery, and the accumulators are removed. (and the nipple near throttle-body is plugged.)

1) the method mentioned by DaveSlow, (and actually the one I was planning to do). Remove all the stock plumbing except the rubber hose with checkvalve on driver's side of intake. Buy some hose and a "T". Run new hose to brake and clutch booster.

2) the method I stumbled on --> cut the clutch hard-line that runs along the fire-wall. Bend it so that the end is close to the brake booster. Attach the stock short rubber hose already connected to brake booster. DONE. . . . Nothing to buy, no fooling with replacing the rubber hose that attaches to clutch booster (hidden down in the engine bay under a bunch of stuff :D)

2a) actually an easier method might be what jba3 did (it is not easy to bend the steel tubing without kinking it) --> cut the clutch line, buy a longer piece of hose, attach it to the brake booster.
.

Bottom line: there are several ways of plumbing the reduction, but there is no good reason to keep the vacuum accumulator tubes, (unless you need
that assist to push in the clutch with engine turned off).

.
 

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Discussion Starter #35
Here's what I have:


Yep, that is similar to what I did. Both methods use the hard-line clutch "T". Only difference is the vacuum source.

My way eliminates that rusty hard-line running across the firewall. :p

.
 

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Here's a few pics of how I did mine, and the vac redux in general:


Pardon the messy EBC/Stereo wires; didn't have any clamps or wrap for them yet You can see the rubber line that comes off the original line, it wraps behind those wires, and connects to where I cut the stock hardline on the firewall there. Very easy, 1 min with a hacksaw, couple mins with files cleaning up, and done. I don't have access to pipe benders, nor the skills to use it, so this was an easier, cheaper solution for me. :)


No hardline to the vac tank, woohoo!


No rusty hardline on the firewall, woohoo!


Mmm, sexy

Definitely love this "mod". Also, as Forrest said, disable the clutch safety switch if you have issues. I have remote start so I don't care, but I tried pushing the clutch the normal way and it was fine. Less pressure than my friends exedy twin HD in his evo. ;)
 

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So this may be a little off topic but I have a few questions.

On the lower hard line that runs across the firewall and next to the battery I have a patch of white furry type substance on there. Doing this reduction gets rid of this but after I cut that hard line off I can completely remove it and not have to cap off where ever this hard line runs down to?





Also would you recommend just using a couple of pliers to bend that line or would that for sure make a kink in it?

Thanks,
Ice
 

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Discussion Starter #38
So this may be a little off topic but I have a few questions.

On the lower hard line that runs across the firewall and next to the battery I have a patch of white furry type substance on there. Doing this reduction gets rid of this but after I cut that hard line off I can completely remove it and not have to cap off where ever this hard line runs down to?

Also would you recommend just using a couple of pliers to bend that line or would that for sure make a kink in it?

Thanks,
Ice
Not off topic at all . . that is the whole point of this reduction, to get rid of that line, (and the tanks it runs to). . . Trace that tubing down under the frame and remove those tanks. ie. don't cap them, scrap them. :D

You could bend the tubing with pliers, but it would be hard to do without kinking. . . . Easier would be to do like jba3 did, and get a longer piece of rubber hose.
 

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I just took the hose off, took it to autozone, and got a long one. It was like $2 or under. :)
 
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