Monday, February 20, 2012

Brake pedal firm when engine not running goes to floor after engine starts?

My brake pedal goes to the floor after starting the engine.
I have a nice firm brake pedal when the car is not running, as soon as Istart the engine, the pedal goes almost to floor.Brake pedal goes almost to the floor after engine starts.
Brake pedal goes to floor when engine on.
Brake pedal goes to the floor.
Brake pedal goes to floor only when engine running.
Brake Pedal goes right to floor when engine starts.

This types of queries are asked by many customers.
In this case the car is toyota Camry.It has ABS brake system.

But this types of problems are very common in ABS brake system cars.

In this case the brake is proper when engine is up,but as soon the engine is started the brake pedal goes to floor.
Holding the foot on the brake when engine is started the pedal goes to the floor .

On basis of this issue,the details to troubleshoot the problem is as follows :----
This types of problems basically occurs after replacing brake pads and brake shoes or if the brake pads and shoes worn out.
If this parts are replaced,but not installed properly,such problem will be noticed.
If you have solid pedal pressure with the engine off is unlikely any air in the hydraulic system. The ABS actuator assembly is not activated and the hydraulic circuits would be going through the actuator assembly and the wheel cylinders. Unless the abs actuator motor buzzes or has been activated is unlikely any air is trapped in the assembly itself. Sometimes well the engine is running if you overpower the brake pedal it can appear as though it is going down too far. If you're comfortable with putting in drive I would attempt to see if the brakes. Under normal conditions. All of this is assuming that you have all of the brake-shoes Springs and retainers installed correctly and adjusted correctly. If the brake drums and shoes are not adjusted correctly you can get over travel due to the vacuum booster applying excessive pressure that you normally would not get with the engine not running. This also is true for the front brake pads. Under vacuum booster pressure if the pads are not installed correctly it can cause a low or spongy pedal. You could remove all the wheels and see how much play you have in the rear brake shoes to drum travel and then have someone push the brake pedal to make sure that the calipers are not flexing or the brake pads are not moving excessively. This would be the only other possible solution.

If you are dealing your brake repair job yourself,then i recommend you to do it very properly.
I've had a lot of apprentices newbie's do four-wheel brake jobs with one wheel cylinder they bleed the brakes then get in and say I start the car and the pedal drops too far. A lot of this is due to over forcing the brake pedal and once the vehicle is driven they find that the stopping power is normal. Obviously you need to use caution when first starting to break this in. If the brakes start to wear in and are adjusted properly you should be able to stop with normal pressure without overpowering the brake pedal.

The low brake pedal  cab be the issue with the rear brakes out of adjustment or the front pads being stuck in the holders. 

This details will help you.
Thanks.

See below the latest solved car problems:-----

How to replace Brake Power Booster?

http://repairhelpcenter.blogspot.in/2012/02/how-to-replace-brake-power-booster.html

1997 Chevy Tahoe Brake lights not working?

http://technoanswers.blogspot.in/2012/02/1997-chevy-tahoe-brake-lights-not.html

How to service Drum brakes?

http://repairhelpcenter.blogspot.in/2012/02/how-to-service-drum-brakes.html

What type of problems usually noticed on Drum brakes?

http://repairhelpcenter.blogspot.in/2012/02/what-type-of-problems-usually-noticed.html

How to test Drum Brakes?

http://repairhelpcenter.blogspot.in/2012/02/how-to-test-drum-brakes.html

Brake Bleeder Screw Function?

http://repairhelpcenter.blogspot.in/2012/02/brake-bleeder-screw-function.html

Replacing ABS unit on Buick Century?

http://technoanswers.blogspot.in/2012/02/replacing-abs-unit-on-buick-century.html

How to Deactivate Airbag system on Ford Ranger?

http://technoanswers.blogspot.in/2012/02/how-to-deactivate-airbag-system-on-ford.html

Brake pedal is pulsating and vibrating?

http://repairhelpcenter.blogspot.com/2012/01/brake-pedal-is-pulsating-and-vibrating.html

All types of brake problems and repairs

http://howtobyme.blogspot.com/2011/11/abs-and-service-light-comes-on.html

What is Brake Drum Bar?

http://repairhelpcenter.blogspot.in/2012/02/what-is-brake-drum-bar.html  

ABS light stays on but brakes work fine?

http://howtobyme.blogspot.com/2011/11/abs-light-stays-on-but-brakes-work-fine.html

VCS maintenance required on Toyota Camry?

http://howtobyme.blogspot.com/2011/11/vcs-maintaince-required-on-toyota-camry.html

VCS and ABS lights go on and off intermittently on Lexus?

http://howtobyme.blogspot.com/2011/11/vcs-and-abs-lights-go-on-and-off.html

ABS & Brake lights warning indicator steady on dash and speedometer not working for Dodge Ram?

http://howtobyme.blogspot.com/2011/11/abs-brake-lights-warning-indicator.html

Isuzu rodeo speedometer is jumping?

http://schematicsdiagram.blogspot.com/2012/01/isuzu-rodeo-speedometer-is-jumping.html

E-brake is stuck down on Ford Focus?

http://schematicsdiagram.blogspot.com/2011/12/e-brake-is-stuck-down-on-ford-focus.html

Brake warning light comes on and car will not start intermittently?

http://repairhelpcenter.blogspot.com/2011/12/brake-warning-light-comes-on-and-car.html

When the car stops, abs pump turns ON?

http://howtobyme.blogspot.com/2011/12/when-car-stopsabs-pump-turns-on.html

Where is Power Brake Booster located on 1995 Lincoln Town Car?

http://howtobyme.blogspot.com/2011/12/where-is-power-brake-booster-located-on.html

Sometimes ABS light comes on while Driving?

http://howtobyme.blogspot.com/2011/12/sometimes-abs-light-comes-on-while.html

How Anti-Lock Brakes Work?


Brake System Troubleshooting?

http://technoanswers.blogspot.com/2011/11/brake-system-troubleshooting.html

Car Brake lines have no pressure?

http://schematicsdiagram.blogspot.com/2011/12/car-brake-lines-have-no-pressure.html

Car Brakes Dragging?

http://repairhelpcenter.blogspot.com/2011/12/car-brakes-dragging.html

Car Brakes grabbing?

http://repairhelpcenter.blogspot.com/2011/12/car-brakes-grabbing.html

Car Brakes Making Noise?

http://repairhelpcenter.blogspot.com/2011/12/car-brakes-making-noise.html

Car Brakes Pulling?

http://repairhelpcenter.blogspot.com/2011/12/car-brakes-pulling.html

Pulsating Brake Pedal?

http://repairhelpcenter.blogspot.com/2011/12/pulsating-brake-pedal.html

Spongy brake pedal?

http://repairhelpcenter.blogspot.com/2011/12/spongy-brake-pedal.html

Hard Brake Pedal?

http://repairhelpcenter.blogspot.com/2011/12/hard-brake-pedal.html

How to Disconnect Power to EBCM on Pontiac Grand Prix?

http://schematicsdiagram.blogspot.com/2011/12/how-to-disconnect-power-to-ebcm-on.html

Where is ABS/TCS module located on 2005 Cadillac Deville

http://schematicsdiagram.blogspot.com/2011/12/where-is-abstcs-module-located-on-2005.html

How to Replace Power Brake Booster on 1996 GMC Jimmy?

http://schematicsdiagram.blogspot.com/2011/12/how-to-replace-power-brake-booster-on.html

Isuzu Trooper Shifts hard and Engine Revving in stop?

http://schematicsdiagram.blogspot.com/2011/12/isuzu-trooper-shifts-hard-and-engine.html

What is Brake Bleeder Screw?

http://repairhelpcenter.blogspot.com/2011/12/what-is-brake-bleeder-screw.html

How to replace car Brake Cable?

http://repairhelpcenter.blogspot.com/2011/12/how-to-replace-car-brake-cable.html

How to Replace Brake Disc?

http://repairhelpcenter.blogspot.com/2011/12/how-to-replace-brake-disc.html

ABS motor keeps running?

http://schematicsdiagram.blogspot.com/2012/01/abs-motor-keeps-running.html

Anti-lock brake light stays on all the time?

http://technoanswers.blogspot.com/2012/01/anti-lock-brake-light-stays-on-all-time.html

Is it necessary to replace Brake caliper while replacing rotors and brake pads?

http://repairhelpcenter.blogspot.com/2012/01/is-it-necessary-to-replace-brake.html

Emergency brake Adjustment for Hyundai Tiburon?

http://schematicsdiagram.blogspot.com/2012/01/emergency-brake-adjustment-for-hyundai.html

How does Brake Backing Plate works?

http://repairhelpcenter.blogspot.in/2012/02/how-does-brake-backing-plate-works.html

How to replace control panel on Audi A4 models?

How to inspect, service and replace brake shoe liner?

How to inspect brake drums?

How to replace Brake light switch on Chevrolet Tahoe?

How to replace brake rotors?

Engine accelerates when brake is applied?

http://technoanswers.blogspot.in/2012/02/engine-accelerates-when-brake-is.html

Loss of acceleration?

http://technoanswers.blogspot.in/2012/02/loss-of-acceleration.html

1996 Chrysler LHS brake light circuit wiring diagram?

http://technoanswers.blogspot.in/2012/02/1996-chrysler-lhs-brake-light-circuit.html

How to replace rear brake pads on 2002 Lincoln continental?

http://technoanswers.blogspot.in/2012/02/how-to-replace-rear-brake-pads-on-2002.html

max