# Anyone tried EV Source's brake vacuum pump?



## notailpipe (May 25, 2010)

I'm disgusted with brake pump solutions, having now tried various solutions, including the VW/Audi pump solution and that still being terribly loud.

EV Source claims their pump to be 40dB, which would be great. If it is really like a "quiet office" then I'll take three!

Wondering if anyone has any experience with this pump or knows more about it.

Otherwise, I'm getting ready to bury the VW/Audi pump I've got in the bowels of the spare tire well and "Great Stuff" the sh*t out of it...


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## dtbaker (Jan 5, 2008)

notailpipe said:


> I'm disgusted with brake pump solutions,



I still think switching to non-vacuum is the best IF you have a graceful alternative to the stock master cyl without booster..... but that is not possible in many builds. ;(

The standard Gast setup from Kta-ev.com works fine, is not awful loud, but is a lot more expensive that I like.


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## notailpipe (May 25, 2010)

Dan,

How is that done, going without vacuum boost?

I looked last night and I can build a thick-walled MDF box to fit in my spare tire well. My current plan (since I already have a vacuum pump and switch, it's the best sunk-cost option) to put it in the box with some eggshell foam lining (not sure where to find that, hobby lobby?) and Great Stuff. Run the inlet line into the box and Great Stuff around the hole. Then run the outlet line out the car, into a little "pocket" void underneath the rear suspension beam (right behind my battery box) and stuff the crap out of it with foam there, so that air can still blow out but it muffles the sound.

Part of it is I want the car to be silent when I'm OUT of the car, because I so far hate showing my car to people and it's on but we're both looking at the front of the car and hearing this blatting sound from inside the engine bay, which of course absorbs sound like a megaphone. So that way, when we're out of the car, the pump is now IN the car, buried in the trunk, and hopefully you can't hear it outside. When we're IN the car, the plan is either that the MDF/foam/layers of carpet/trim is enough to muffle it enough, or in that case we're likely actually moving and thus you can't hear it anymore over road/traffic noise.


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## dtbaker (Jan 5, 2008)

notailpipe said:


> Dan,
> 
> How is that done, going without vacuum boost?


the most likely way is to find a master cylinder that has a bore about 1/16" smaller, and the same number of outlet ports in the same orientation to minimize brakeline re-work. SOME vehicles have easy matches from older models pre-powerbrake days. So far, the suzuki swift/geo metro does not seem to have an easy swap, so there is no real cost or time savings by the time you look at all the work required.




notailpipe said:


> Part of it is I want the car to be silent when I'm OUT of the car, because I so far hate showing my car to people and it's on but we're both looking at the front of the car and hearing this blatting sound from inside the engine bay,


it shouldn't be running... unless you've stepped on the brake pedal couple times. I generally include that as part of a show.n.tell to explain the systems you have to convert that most people might not think about; like the heater and vacuum.


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## dladd (Jun 1, 2011)

Not the pump in question here, but probably similar. I have this one from Summit Racing. It has an integrated pressure switch and is plumbed to a fairly large reservoir, it generally kicks on after every other braking event. 

I installed a muffler (4427K71 on this page) and put it on the 'blow' side of the vacuum pump in my car. It definitely quieted it down, but I still can hear the pump. It did lower the frequency of the exhaust noise to a much more pleasant 'rumble' instead of the higher pitched thumping it used to be. My next step is to further isolate it from the chassis to minimize transmitted vibrations (currently it's rubber mounted to a solid mounting plate, I'm going to move it to a floating metal plate instead for two layers of rubber mounting). This will not help with the exhaust noise, but I'm hoping it will reduce transmitted pump noise a little bit more.

I also installed a toggle switch on the dash so I can manually shut off the pump. It's OK now, once driving it's quiet enough I don't hear it except at a stop light, and I can just shut it off when entering a parking lot, before turning on the car, or any other time I want the cool EV effect.

I've found that if I forget to turn it back on, that it's a gradual thing, the loss of braking power. I get plenty of notice that the vacuum is running low and just turn it back on.


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## notailpipe (May 25, 2010)

dtbaker said:


> it shouldn't be running... unless you've stepped on the brake pedal couple times. I generally include that as part of a show.n.tell to explain the systems you have to convert that most people might not think about; like the heater and vacuum.


Dan, I don't know if you remember but my vacuum system also had a leak somewhere, which is only exacerbating the annoyance. For round #3 of the brake design, I am going to go with a reservoir-less system. I think I had a leak through the cheapie China vacuum gauge I put in it. (I have typed "cheapie China" like a million times on this forum... maybe it's time to stop throwing my money away). So that will help and it should be true what you say that it _shouldn't_ be running. Of course, it always will run when I first turn it on which is often when I'm showing it off to people.

It's kinda unfair how an ICE can be so loud and people think "aww yeah baby, power!" but then they hear a vacuum pump that is actually much quieter than an engine and think "ugh... I'd never drive that!" We don't have collectively billions of dollars in marketing telling us otherwise yet..


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## notailpipe (May 25, 2010)

dladd said:


> I installed a muffler (4427K71 on this page) and put it on the 'blow' side of the vacuum pump in my car. It definitely quieted it down, but I still can hear the pump. It did lower the frequency of the exhaust noise to a much more pleasant 'rumble' instead of the higher pitched thumping it used to be. My next step is to further isolate it from the chassis to minimize transmitted vibrations (currently it's rubber mounted to a solid mounting plate, I'm going to move it to a floating metal plate instead for two layers of rubber mounting). This will not help with the exhaust noise, but I'm hoping it will reduce transmitted pump noise a little bit more.
> 
> I also installed a toggle switch on the dash so I can manually shut off the pump. It's OK now, once driving it's quiet enough I don't hear it except at a stop light, and I can just shut it off when entering a parking lot, before turning on the car, or any other time I want the cool EV effect.
> 
> I've found that if I forget to turn it back on, that it's a gradual thing, the loss of braking power. I get plenty of notice that the vacuum is running low and just turn it back on.


Two really great ideas in one post... thanks! 

I love the idea of a toggle inside the dash! I put my toggle in the project box because I thought of it as a debug feature, but yeah there might be times I want to turn it off and show off. Of course, if I design the baffling right, I might not need this, so we'll see how it goes but that's a very good back-pocket idea.

I have also been looking for a muffler but didn't know where to find them. Thanks for the link. I wonder if Grainger sells something similar, cause there's one here in town that I could get now...


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## dtbaker (Jan 5, 2008)

notailpipe said:


> Dan, I don't know if you remember but my vacuum system also had a leak somewhere, which is only exacerbating the annoyance. For round #3 of the brake design, I am going to go with a reservoir-less system.


I think you'll find that a liter or two of vacuum res, and a system that isn't leaking, would eliminate your annoyance... I really can barely hear the pump from inside the car when stopped, can't hear it at all when moving, and LIKE to hit the brakes a couple times in demo, and then ask people if they can guess what it is and why it is needed.


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## notailpipe (May 25, 2010)

dtbaker said:


> I think you'll find that a liter or two of vacuum res, and a system that isn't leaking, would eliminate your annoyance... I really can barely hear the pump from inside the car when stopped, can't hear it at all when moving, and LIKE to hit the brakes a couple times in demo, and then ask people if they can guess what it is and why it is needed.


Hmmm... I've been reading around some more and might possibly have a leak at the actual brake booster or the check valve. I guess those are the first to test, or maybe I can buy an aftermarket check valve for pretty cheap and save a little guesswork.

I'm also wondering how I should hook the sensor and check valve into the system if it's going so far from the master booster. I was originally thinking that I'd want the check valve coming first from the brake booster, then the tube runs to the trunk, where it's connected to the Square-D switch, pump, and possibly reservoir (I can salvage my old reservoir easily, make it a little smaller). But now I'm realizing that may leak right at the pump and always be on. So now I'm thinking I should run the tube from the booster all the way to the trunk, then put the switch and possible gauge at the same node, THEN the check valve, and then the pump last. Like this post here. That should eliminate any leaking from the pump itself.

Other remaining sources for the possible leak are (please post your opinion on how likely this is a cause):
1. When I threaded the barb connectors into my reservoir, I used that black ABS goop on the threads. I thought it dries pretty solid, it's made to join pipes. Should I have coated threads with vacuum paste instead (that yellow/white crud I've seen in pictures)? Where do people buy that?
2. I've heard people talking about the actual grommet on the brake booster leaking. When it leaked fast in the past, I heard a loud whooshing but not every time. What exactly is the grommet on the booster and how might I check it, if anyone knows?

Thanks


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## dtbaker (Jan 5, 2008)

notailpipe said:


> ...might possibly have a leak at the actual brake booster or the check valve.


the check valves do sometimes come DOA, they are cheap, try another one. Regardless, the pump needs to be LAST in the line because piston pumps ALWAYS leak a little.



notailpipe said:


> I'm also wondering how I should hook the sensor and check valve into the system if it's going so far from the master booster.


 shouldn't matter too much, but with a LONG vacuum tube run you are going to get a lot of 'spring' in the system from the tube itself contracting under vacuum. short runs are better, so maybe put everything but the pump under the hood.



notailpipe said:


> Should I have coated threads with vacuum paste instead (that yellow/white crud I've seen in pictures)? Where do people buy that?


black ABS cement is made to glue together ABS to ABS. It won't work well ABS to metal. The teflon thread paste is in the plumbing supply of any hardware store....





notailpipe said:


> 2. I've heard people talking about the actual grommet on the brake booster leaking. When it leaked fast in the past, I heard a loud whooshing but not every time. What exactly is the grommet on the booster and how might I check it, if anyone knows?
> 
> Thanks


hhhmmm, if your brake booster had problems in the past, I guess it may need to be rebuilt. I've never had one fail.....


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## notailpipe (May 25, 2010)

Cool, thanks for the help. I'll try the teflon paste this time (better than tape I assume), that might've been my problem.

The brake booster never seemed to have a problem in the past, but then again I had an always-on engine so I never had the chance to see if it was having a small leak or not.

I'm looking at this check valve from McMaster-Carr. What do you think?










I don't understand how a one-way valve can be "installed in any direction," how would it then "know" which is the right way? I'd prefer to find one that's one-way for sure on here, but otherwise it seems to meet my specs.


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## favguy (May 2, 2008)

They probably mean any orientation, ie. vertical or horizontal.

Did you get the pics. ok?

Regards

Paul


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## Duncan (Dec 8, 2008)

Hi Notailpipe

Your Honda is not a large car 
IMHO brake boosters are not necessary for small cars 

I would look at moving the pedal pivot point to get more leverage and going manual


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## notailpipe (May 25, 2010)

favguy said:


> They probably mean any orientation, ie. vertical or horizontal.
> 
> Did you get the pics. ok?
> 
> ...


Ah, that makes sense. Poor choice of words for a directional valve.

I did get your pictures, thanks, I'll reply to your email shortly.


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## notailpipe (May 25, 2010)

Duncan said:


> Hi Notailpipe
> 
> Your Honda is not a large car
> IMHO brake boosters are not necessary for small cars
> ...


Hmmm, yeahhhh... but it is actually quite heavy now with the added batteries. Without power brakes it requires me to put all my weight on the pedal and the parking brake to get it to stop, so that's a lot of manual leverage needed.

It seems like nobody has actually tried the EV Source brake pump. And I'm like 0 for 3 ever hearing back from those guys (I emailed them to ask if they'd sell it separately to me, not the whole kit). So I think I'm going to just bite the bullet and try to get my original Thomas pump to be quiet. 

I've learned a few things that I'm going to try. One, I think I possibly had a bad cheapo check valve from AutoZone that was causing the faster leaking, making it more annoying than it needed to be. Two, I now have the Square-D switch so I can set a larger deadband between switching, which should alleviate annoyingness. Third, I'm going to mount it in my insulated/padded box which should kill 95% of the sound, and then for the rest I bought a 30dB muffler (that's pretty good, if it's actually that good) for the outlet port from McMaster-Carr.

We'll give this a try and I think iteration 3 will be the final one... fingers crossed.


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## Duncan (Dec 8, 2008)

_Hmmm, yeahhhh... but it is actually quite heavy now with the added batteries. Without power brakes it requires me to put all my weight on the pedal and the parking brake to get it to stop, so that's a lot of manual leverage needed.

_With power brakes the pedal will have a leverage ratio of about 3:1 
Manual brakes have about 6:1

The flip side of course is more pedal movement - 

Saying that well set up manual brakes don't need the movement to actuate a servo valve, so manual brakes always feel more direct to meTo me on a light car servo brakes and power steering are unnecessary for a normal fit person


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## EVfun (Mar 14, 2010)

I like manual brakes. I would discourage anyone from converting a car from power brakes to manual brakes if there are not factory pieces for that model or a similar model to donate the parts. If you find the brakes are suitable without the brake booster you could remove it and fabricate an adapter for the master cylinder and new pushrod, most likely with available aftermarket parts.

The braking system on modern cars is a split system so the brakes will stop the car if one caliper or wheel cylinder blows. If you move the pivot point to gain the leverage needed for manual brakes you must carefully verify that if one front bleeder valve is wide open the remaining half of the master cylinder will build pressure and apply solid brakes to the other 2 wheels. The same test needs to be done if you use a smaller bore master cylinder to decrease the brake force. With either method of reducing pedal effort each inch of pedal movement will move less brake fluid. When you have a 1/2 brake failure the master cylinder will drop about 1/2 way before building pressure in the other half.


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## Yukon_Shane (Jul 15, 2010)

I purchased my brake vacuum pump from Evolve but it looks identical to the one you've reference from EV Source.

My EV isn't on the road yet but I've had the vacuum pump installed for some time now and it seems pretty quiet to me. The oil filled muffler does a good job and even with the hood off I don't find it overly load or annoying.

That being said, it does make *some* noise and I don't doubt that if it was running the entire time the ignition was on it would probably start to annoy me.


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## tomofreno (Mar 3, 2009)

I have the same kit, but purchased it from evcomponents about 2 1/2 years ago. It is made by YT Stable Tech Corporation. The pump is audible from inside the car when sitting in my garage. It is usually not audible at a traffic light since the noise of the ice vehicles around me drowns it out - is if I am the only vehicle. It is also not audible when moving, since the tire noise masks it, so I seldom notice it while driving. I have no reservoir tank. The pump comes on about 2 seconds when I hit the pedal, sometimes not at all.

I have the pump bolted directly to a steel bracket, with no damping, right next to the firewall. I've been meaning to isolate it with some rubber, but...well, I don't notice it that often. My ears may be older than yours. Then there were those rock concerts...



notailpipe said:


> I'm disgusted with brake pump solutions, having now tried various solutions, including the VW/Audi pump solution and that still being terribly loud.
> 
> EV Source claims their pump to be 40dB, which would be great. If it is really like a "quiet office" then I'll take three!
> 
> ...


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## piotrsko (Dec 9, 2007)

Disregard, I read the title of this thread


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## Lordwacky (Jan 28, 2009)

I have this pump (purchased from EV components). It works fine, its audible, but I don't think it is too bad. I coupled it with a homebuilt ~2liter reservoir. So far the system has been working fine and is not as aloud as other systems I've heard. I can usualy get 3 or so pumps of the brake peddle before it engages and then it only runs for ~10 sec. So far the pump has been working fine. I have ~ 1k miles on my conversion to date.


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## Joey (Oct 12, 2007)

There are two principles in trying to reduce pump noise - isolation and absorption. For isolation, rubber mounting the pump is good. Mcmaster-Carr sells isolation mounts that work well. 

The quality of the enclosure is important. A sealed enclosure is best, if heat build up isn't a problem. If venting is required, then there are lots of designs the utilize baffles lined with absorbing material, such that there is no line-of-sight path into the enclosure. The enclosure walls should be very stiff. Constrained layer damping is often used to stiffen and add damping to enhance isolation and attenuation.

The inside of the enclosure is lined with absorbing material. I'm not sure how effective egg crate foam is for the relatively low frequency of the vacuum pump, but is better than nothing. Dense absorbing material is better for lower frequencies. There are specialty panels for this purpose, but they are expensive

Starting with a quieter pump means you can get away with using only a few of these techniques.


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## notailpipe (May 25, 2010)

Thanks everyone for the feedback. 

I think for now I'm going to try my idea of mounting it all in a sealed enclosure in the spare tire well, using many of the ideas that Joey also mentioned. I'll be using a Thomas pump that I've got, and if it's still too loud then maybe I'll consider using this pump since it sounds like it really is fairly quiet off the bat. On the other hand, I'm using a high noise-reduction muffler from McMaster-Carr too, so if that's how they're getting this pump so quiet then maybe I'll be good with my current pump. And the muffler I'm getting requires no oiling or maintenance so that's good too (probably not as many dB reduction).

I'll keep you posted when I finish it, if not this weekend, next.


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## powerhouse (Apr 1, 2011)

Hey notailpipe
Did you ever finish this up? How did it turn out?


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## notailpipe (May 25, 2010)

Thanks for the reminder, I've gotten way behind in my posting. The brakes are done and are working great!

I put the whole system in a MDF box in my spare tire well. I also kept a reservoir, shortening my original one a bit to make it like a foot long. In the postmortem of my old system, I discovered the culprit of the massive leak: a cheapie autozone check valve. I just reused my OEM checkvalve by Honda and in my new system it can hold a vacuum more than 15 minutes without noticing any movement on the vacuum gauge (that's as long as I cared to check).

When it pumps, you can definitely still hear it in the garage. But it's not too terrible. It's quieter than my wife's Lexus, but I think it's psychological - you just don't expect an electric car to make any sound. When you're driving and it's pumping, or if you have the radio on, you can't hear it at all.

I love my Square-D switch! I adjusted the hysteresis so I can usually go 2, sometimes 3 brake pumps before it kicks on. No more jostling start/stopping... so annoying! 

I will update with more details and pictures when I eventually update my actual build thread. I also plan to write a short post on how to adjust a Square-D vacuum switch, cause I couldn't find that info on DIYev.com, though it's probably not too hard to figure out.


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## Pierre spiteri (Apr 13, 2009)

notailpipe said:


> I'm disgusted with brake pump solutions, having now tried various solutions, including the VW/Audi pump solution and that still being terribly loud.
> 
> EV Source claims their pump to be 40dB, which would be great. If it is really like a "quiet office" then I'll take three!
> 
> ...





have you fixed the problem? i just converted a car and the sound of the pump is annoying

thanks

pierre


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## Roderick (Dec 8, 2013)

Any update? 
Planning to get one soon. They are little expensive therefore I might purchase used hella up 30 or 32. (i hear they are quiet too?)


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