# Brakes Not Strong Enough



## EVfun (Mar 14, 2010)

What do you mean, "My brakes are not tight enough"? What are they doing or not doing that concerns you?


----------



## TEV (Nov 25, 2011)

If you have power brakes but you don't have a vacuum pump installed yet, I think it's only normal to have " not strong enough" brakes. If you do have the vacuum pump you have to check how fast and how much vacuum it's makes. Just search for vacuum pump on this website and you will find all the informations you need. Good luck.


----------



## Frankencar (Nov 17, 2008)

I do have a vacuum pump installed. It is the kit from ElectroAuto. But it doesn't seem to be doing enough to boost the brakes. I know I added 1000 lbs of batteries, but I would still expect better brakes than what I am getting.


----------



## TEV (Nov 25, 2011)

You have to check how fast and how much vacuum it's makes.


----------



## Frankencar (Nov 17, 2008)

TEV said:


> You have to check how fast and how much vacuum it's makes.


How would I do that?


----------



## evnz (Jul 24, 2010)

What are the brakes disc or drum and how worn are they,have you got a extra tank between the pump and brakes and lastly have you checked for leaks


----------



## mizlplix (May 1, 2011)

From direct personal experience, I went from a 1981 Ford Escort ICE to an EV. I got to drive both iterations of the same car, The EV version sucks when stopping. Yes, it had a vacuum pump (from Graingers)

My 20 6volt GC batteries weighed 68Lbs each. 20 X 68= 1,360 Lbs.
The batteries were the culprit. It drove like it was heavily loaded (and stopped like it too). 

So, I installed Escort Station-Wagon brakes, (larger rotors, drums and their own specified master cylinder). VERY little improvement, even with a vacuum pump. I made a large tank to boost the vacuum volume. It did give me 4 complete applications of the brakes before I ran out of boost. Before, it had 2 applications before getting rock hard and not stopping)

Vehicles are rated in GVWR ratings. A vehicle rated to carry a 1,000Lb payload is like a 3/4Ton pick up or cargo van. And they still let you know you have a load in them. What chance does your much smaller car have stopping/carrying that load?

Even with band-aids applied, you are not going to make it act/drive like it was a normal car.

(I am a life long mechanic/race mechanic, car designer and builder. I am not some guy that can "Change my own spark plugs".) I kinda know my way around the mechanical world. 

You will not make your car act or stop like it was 1,000# lighter. You need to plan and look ahead while driving, to be aware of things around you and try to not be in a position where you need to do a panic stop.

A lead/acid vehicle is a great one to "get your feet wet" in the EV world, but between now and when you need another set of batteries, you need to decide....

1. Do I drive my car enough to consider it my primary vehicle?
2. How many near misses have I had due to the "heavy car syndrome"?
3. Do I spend a lot of time on EV maintenance?
4. Are you committed to continuing the EV lifestyle?

You have at least 2-3 years to ponder those questions before you will need a pack replacement. 

I disagree with you on one of your early points on building an EV. I have owned 3 of them, built 2 others and helped others on many more. 

I have come to the realization that a "Cheap" donor is not the important factor. Cheap is a good thing, but not a deciding factor. 

1. Paint is expensive. Get one with good paint.
2. "Ugly is forever". Pick a car that you like, appearance wise.
3. Transmission type is crucial. Get a car you do not have to change out major components.

Documentation is good. Keep a record of battery voltages, water usage, ETC> 
It will let you go back and understand why certain things happened. 

Good luck with your car and stick with it, it will be worth it to you in years to come.

Miz


----------



## piotrsko (Dec 9, 2007)

My best guess, based on his other threads, is that the booster diaphragm has developed a leak. not as critical when running an ICE because max vacuum occurs during braking.

replace the vacuum booster. test the vacuum lines for leaks by unplugging the booster, sealing the line and see if the pump shuts off.

The Ranger will lock up all 4 even with 1190 lbs of lead in the back, down hill, at 55 mph.


----------



## PStechPaul (May 1, 2012)

Has anyone tried using a hydraulic brake booster for an EV? Of course it requires a hydraulic pump but if you have power steering you will have that already:
http://www.cdxetextbook.com/brakes/brake/comp/hydrobrakebooster.html

Or perhaps use electric linear actuators rather than the vacuum booster:
http://www.thomsonlinear.com/website/kor/kor/download/document/Linear_Actuators_bruk.pdf
http://www.autofieldguide.com/products/better-brakes-for-active-safety
http://www.nookindustries.com/CCactuator/CCactuatorFeatures.cfm
http://www.conti-online.com/generat...chassis/download/daten_und_fakten_2012_en.pdf

Would it be possible to use an air compressor to pressurize the opposite side of the power booster diaphragm usually just connected to atmospheric pressure? Here's an explanation of how it works. Seems like it would be possible:


----------

