alternator problem = no brakes??

ten45 · 06-10-2007, 07:32 AM

was going to use my carnival '01 this morning when i heard a disturbing sound after starting. i'm guessing it's the alternator bearing or something. 'charging' indicator light is on. what surprise me is that the brakes indicator light is also on. and after a few minutes when i tried to park it back, i loss brakes and hit my garage! put it in REVERSE while stepping on the brakes but the car moves back. no brakes. put it in DRIVE and same thing. i turned off the car, checked the brake fluid and everything else looks normal. started the car again and brakes are back. but still the indicator lights for both the brakes and charging are ON. and that rattling sound is still there. now I'm worried to drive the car to the shop to check the alternator as i might lost brakes again. is it safe to drive the car? anyone have experienced this before? would appreciate if anyone can help.

07rio5 · 06-10-2007, 08:24 AM

Wow...

You have two individual issues going on here. That they seem to have happened simultaneously is coincidence...

Losing your alternator in no way should effect your brakes working. Even if you had an electric booster and it went out, you'd still have the hydraulics of the brake system. You'd just have manual brakes.

Look for leaks at all the brake line joints, wheel cylinders (if you have drums), master cylinder, etc. Or your master cylinder went out.

With the alternator, remove the belt and turn it by hand.

You can also take it to an AutoZone or something and have it checked...

ten45 · 06-10-2007, 09:42 AM

thanks for the quick reply. I was also thinking they are 2 different issues. however, with car computers/electronics nowadays, i'm not sure if alternator current issues can make the program dumb? mine have ABS. anyway, i'll do another safe road test later and see how it goes. still, if anyone have other inputs....

pepper · 06-10-2007, 03:00 PM

if its a Diesel engine you have then the alternator also provides the braking effect. the brakes should still work but will take about 10 times the foot pedal pressure to activate. The Servo for the brakes is on the back of the alternator so it does both jobs at once.

ten45 · 06-10-2007, 09:26 PM

pepper,
yes, mine is diesel. so how does this servo work exactly? could the local alternator shop knows how to repair it? this is good information. thank you!

ten45 · 06-12-2007, 08:03 AM

i had my alternator replaced yesterday. the rattling sound comes from the pulley or bearing. it maybe the rotation is slipping or stopping causing the servo to generate weak vaccum for the brakes. it is also not charging properly that is why i decided to replace it with a a brand new alternator. those indicator lights now make sense to me. therefore, alternator problem sometimes = weak brakes for diesel engine. thanks!

07rio5 · 06-12-2007, 11:43 AM

Quote:

Originally Posted by pepper

if its a Diesel engine you have then the alternator also provides the braking effect. the brakes should still work but will take about 10 times the foot pedal pressure to activate. The Servo for the brakes is on the back of the alternator so it does both jobs at once.

Well, no sh!t ?! It's always cool to learn something new

So, a servo provides power to a vacuum pump to allow power-assist? That still doesn't explain loss of hyd-pressure, right? Can ya give me the quick run-down?!

Heh... lose your alt and loose your brakes... whatta concept!!!

bloody13 · 06-15-2007, 03:50 AM

I haven't known any instance that the alternator affects any brake part like its Mazda brake shoe causing malfunction on braking system. Perhaps this is just a conclusion based on your personal experience.

54FLX · 06-19-2007, 06:16 PM

The alternator does not supply power to the brake servo. The brake servo is on the end of the alternator and is driven on the same shaft as the alternator via the pulley off the engine. It just happens to be part of the alternator and is supplied as one (expensive) unit. If you look closely you will see two pipes attached to the end of the alternator on the opposite end to the pulley.

sln8458 · 07-13-2007, 07:38 AM

Guys

Modern brakes have/are servo assisted, actually they use the vacuum in the intake maifold, to help/assist the brakes. However this only works on petrol driven engines. So on diesel powered cars a vacuum pump is fitted to generate the vacuum assistance to the brakes. On some cars they are independant units which are belt driven and others (and the Sedona appears to be one) have the vacuum pump as part of the alternator, so if the alternator goes south so does the brakes

look here > > Car Bibles : The Brake Bible 2/3rds down the page

SteveN