# EV Brakes



## jmygann (Jul 26, 2007)

What are most of you using for brake assist ? 

How much does it cost ??


----------



## ecofriend (Jul 26, 2007)

Check out:


http://www.driveev.com/jeepev/convpgs/pbrakes.php


----------



## Mannyman (Jul 26, 2007)

I upgraded the drum brakes to disc. If that isn't enough I have a vacuum pump and reservoir tank (fat pvc tube) on stand-by.


----------



## Adrian (Jul 26, 2007)

Because a typical conversion adds 1,000 pounds to a vehicle, good brakes are a must. Power brakes can be restored with a vacuum pump. There are 2 common types:

#1: Gast/Thomas pump $220 + Pressure Switch $23-$90 + Check valve $10 + Accumulator + barbs, hoses, fittings, etc.

OR

#2: MES vacuum pump with built-in pressure switch and check valve $324 + Accumulator + fewer barbs, hoses, fittings, etc.

EV Parts, KTA, and Electro Automotive sell parts for #1
Metric Mind sells the pump in #2

An accumulator can be made from a 12" length of 4" diameter PVC/ABS pipe with caps glued to both ends. Don't forget to calibrate/test external vacuum switches. And ALWAYS use a properly sized fuse on electrical wiring!

Upgrading rotors/calipers/drums/master cylinder is another option, but it can be tricky. Bigger isn't always better. Some combinations of parts can cause excessive pedal travel, increased drag, or brakes that require excessive pedal force. Brake proportioning may also have to be adjusted, especially if the front/rear weight balance changed during the conversion. Racing websites usually have good suggestions for upgrades.

Drums may not be sexy, but they have some good qualities for EVs. Properly adjusted they won't drag. They are "self actuating" to some extent - once initial braking force is applied they tend to brake harder - making them good for emergency/parking brakes.


----------



## Mr. Sharkey (Jul 26, 2007)

One of my "To Do" projects on the Rabbit EV is to swap over from manual brakes to a late model VW ABS "hydraulic modulator" master cylinder assembly. This unit has an internal 12 volt high pressure hydraulic pump that creates pressure to run the system. I have no plans to get the anti-lock system installed and running, but the modulator assembly will work fine without the wheel tone rings and associated wiring.

No noisy and expensive vacuum pump required. I guess if my car was a conversion and already had a booster servo installed, I'd think about a vac. pump instead.

As for upgrading brakes, I went to four-wheel discs, teflon/braided stainless steel flex lines throughout, vented GTI front rotors, and performance pads. Stopping is adequate, but pedal effort is moderate to difficult, depending on the level of panic one is experiencing at the time.


----------



## Coley (Jul 26, 2007)

*Brakes not a problem*

Since my Yugo is lighter now than before the conversion, brakes have not been a problem.
May add a vac pump and tank at a later date.


----------



## moldiebrownie (Aug 29, 2007)

As Adrian mentioned...racing websites are a good place to go for brake upgrade info...especially Honda Civics. In my case I found a site that gave me the complete blueprint to upgrade my brakes. I did retain my 8" booster however and my brakes are rock solid. Read my album entry for more info and the link. 

When it came to the vacuum pump, I followed Ken Norwick's advice here http://www.docdockdocuments.com/conversion/Conversion20.htm
and the next page http://www.docdockdocuments.com/conversion/Conversion23.htm

I went to my local "PICK YOUR PART" wrecking yard in Northern California http://www.pickapart.com/ . They have occasional 50% weekends and in fact...everything I got for my civic, I waited for these. Anyway, I hunted down 4 of these pumps with my buddy Karl http://www.austinev.org/evalbum/1259
and I swear...we got them for like 16 bucks a peice I remember. This pump is fantastic! We hooked one up to 12 volts, plugged the suction tube and immediately the pump quit. Unplug the tube and it turns right back on all by itself because it has a built in vacuum switch. With my home made PVC vaccum reservoir..it works great! My small reservoir is only enough for two brake applications before it comes on but it takes like 15 seconds for the pump to take it down and shut off again. I need a bigger reservoir. Of the four we got..only 3 actually worked though. Here is another link that shows you what cars actually had it and how to install it http://www.gmcmotorhome.com/tech/vacuum_pump/index.html It is aimed at RVs but it suits our purposes as well. All the vehicles I found it on had it located inside the driver's side front wheel well. Its kinds of hidden so another clue to finding the right car is to look for a vacuum hose coming from this location and going to the booster....a sure sign one is down there. Make sure to get that nice weatherproof electrical connector with wires and leave a length of vacuum hose attached to the the pump so you can stick the check valve in it...extra value...heh heh.  
Another bonus is that this unit is compact and light...look where I mounted mine! I also have a length of left over vacuum hose attached to the exhaust side and leading down to the ground to muffle it somewhat and with this hose attached..its really not that noisy at all. Some more tips that may save you a return trip if you go hunting for it. 1. bring "Torx" bits to take off the three mounting bolts..like these http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=94188 I dont remember what size specifically though. 2. Bring canned air...like the type you use to blow dust out of your keyboard. The pump sits below where the battery is and the Torx bolts are right below the battery so there is alot of corrosion. I couldn't even see the bolts until I blew out the dust and rust flakes. 3. After blowing out the dust/rust particles to expose the 3 bolt heads...soak them for a bit with a good penetrating oil because THEY WILL STRIP if you don't most likely. I had to abandon 2 clean looking pumps when I did this and move on to fresh ones when I later came back with the canned air and oil. Hope this helps somebody!


----------



## Coley (Jul 26, 2007)

How about this?
Put a very small air compresser inside a vac tank and run it? Put the pressure side to the outside of the tank.
WALAH....a vac pump.


----------



## KiwiEV (Jul 26, 2007)

I've heard of that idea and I came very close to doing it myself.


----------



## moldiebrownie (Aug 29, 2007)

Coley said:


> How about this?
> Put a very small air compresser inside a vac tank and run it? Put the pressure side to the outside of the tank.
> WALAH....a vac pump.


 
You still gotta buy a vacuum switch though...more money and when I was hunting down parts initally for my brake system..I did not find any cheap ones. 

This idea gives me another idea...what if you take the pump I mentioned above and just put it inside a vacuum reservoir with the exhaust side exiting the tank. I made mine like everybody usually does out of pvc tube and endcaps with brass barbed fittings. This would be a good way to make it virtually silent too....hmmm..I already wanted to make another bigger reservoir...I just might do this.


----------



## Coley (Jul 26, 2007)

Ok, mount a small PRESSURE switch inside the container also. It would cover the atmoshperic pressure and shut off the motor...


----------



## moldiebrownie (Aug 29, 2007)

I still think your best bang for the buck is the little pump I was talking about earlier if you can get one from a wrecking yard. Heres another EV link talking about it.... http://www.users.voicenet.com/~tnichols/EV/escort05.html .....and here http://www.geocities.com/RainForest/Vines/5565/powrbrak.html


----------



## sl.whiteside (Sep 25, 2007)

Coley said:


> How about this?
> Put a very small air compresser inside a vac tank and run it? Put the pressure side to the outside of the tank.
> WALAH....a vac pump.


A great idea! Only worry would be that these pumps rely on air for cooling the motor and the compression cylinder. You might want to add some extra heat sinking to maintain the reliability of the pump. I would also put an inline filter on the output of the tank to keep compressor grit out of the line.


----------



## Greenflight (Sep 13, 2007)

I got a whole setup, used, for $125. Switch, Thomas pump, and PVC reservoir. 

For my next car, I'll probably buy a used pump like moldie's talking about. Definitely sounds like a great way to save a few $$... Plus the built-in switch sounds nice. The switch I'm currently using is huge.


----------



## petty (Jan 24, 2009)

The source of power for the brake booster on virtually any modern car is engine vacuum. This is not available on an EV, but it can be easily replaced by installing an electric vacuum pump which will feed the brake booster. Btw, anybody tried the avanti electra retrofit kits and smoked tail light covers for EV? or any other brakes you can suggests?


----------



## jmygann (Jul 26, 2007)

Anyone know about this ....

http://www.asiannet.com/more_products.asp?re_id=179570&rid=2394


----------

