Soft Brake Pedal - Toyota Nation Forum : Toyota Car and Truck Forums

REDSOXTICKET · 03-24-2005, 06:58 PM

after the rear "disc"brake pads (Camry 01, V6) were replaced without removing or disconnecting the brake lines. I was able to compress the caliper piston with a C-clamp.

The problem is that the pedal is now soft. The resevoir is filled with fluid and I have been pumping the brakes but still it is "somewhat" soft. Note that the pedal was not soft before I replaced the rear pads. I did not want to bleed the brakes that is why I did not touch the brake lines.

I will be replacing the front pads, could it be that the pads being new in rear and old in front is causing the soft pedal ?

When I compressed piston of the first rear caliper, I noticed that I did not take the cover of the brake resevoir but I did remove the cover when I compressed the second rear caliper. Could this have anything to do with the soft pedal ?

Only when both rear pads were replaced did I start the car and pump the brakes ?

THX

97&02camryleI4 · 03-24-2005, 08:04 PM

It it were me, I'd double check everything that was installed. For good measure, I'd bleed the brakes or possibly flush with new fluid, even though the line wasn't opened. It's like finishing half a job if you're just changing brake pads and/or rotors but not replacing the brake fluid. A lot of people don't bleed their brakes after they change their pads and it works fine for them. But that's just me. Good luck.

toyrolla · 03-24-2005, 09:23 PM

Quote:

Originally Posted by REDSOXTICKET

after the rear "disc"brake pads (Camry 01, V6) were replaced without removing or disconnecting the brake lines. I was able to compress the caliper piston with a C-clamp.

The problem is that the pedal is now soft. The resevoir is filled with fluid and I have been pumping the brakes but still it is "somewhat" soft. Note that the pedal was not soft before I replaced the rear pads. I did not want to bleed the brakes that is why I did not touch the brake lines.

I will be replacing the front pads, could it be that the pads being new in rear and old in front is causing the soft pedal ?

When I compressed piston of the first rear caliper, I noticed that I did not take the cover of the brake resevoir but I did remove the cover when I compressed the second rear caliper. Could this have anything to do with the soft pedal ?

Only when both rear pads were replaced did I start the car and pump the brakes ?

THX

Toyrolla's Rule of thumb:

When in doubt, bleed the brake system; starting with the wheel most far from the master cylinder to the closest.

Although I've used a C-clamp when changing pads, I still bleed the system as a precautionary measure.

What I can also recommend is a one man bleeder that you can probably get from your local auto parts store.

I used this and it cut the bleeding process for all 4 wheels in half with great results.

$7 to make my life easier is $7 well spent.

Good luck in resolving your problem.

NEME5IS · 03-24-2005, 10:30 PM

how do you use that one man bleeding tool?

REDSOXTICKET · 03-25-2005, 03:56 PM

Hello again, we'll I purchased the one man bleeding kit.
I started with the right rear, left rear, right front and left front as per the haynes manual.
I did this twice around and using almost 64 oz. of fluid.

These are the results. I also have some questions if you don't mind commenting.

Car off: The brake pedal goes to about three inches from the floor and can't go no more.
Is this normal ? Remember there are rotors all away around with new pads.

Car on not driving: The brake pedal can reach the floor. Is this normal, can someone let me know by testing this on there car ?

Car on and driving: The car stops suddenly (I guess), no skidding, ABS engaging. If I stop to suddenly it is probably because I hit a wall.

What is considered good braking distance ? (Miles per hour vs. distance) This way I can test the brakes.

THX

Edit
________________________________________________

I bleed the brakes with the car off or should the car be running ?

Does the all air escape into the one man kit bottle ?

Wouldn't the typical bleeding method of building up pressure by pumping the brake with the bleeder valve closed then open the valve slightly when the brake pedal is down to relieve the air better then the one man bleeder method ?
The one man method: You open the valve just once and air comes out along with fluid. I drove at least 16 oz of fluid thru the brake.
Could air still be in the line if 16 oz fluid is going thru the bleeder valve ?

THX

Bmaintz · 03-25-2005, 05:39 PM

I just bought this one man bleed bottle ($7.00) & it works great.... I had replaced the back brake linnings (had 1/2 firm peddle before)..... I did not break the bleeder or any leaks around the brake wheel cylinder, I did move the contact pistons around to get new rubber boots on (must have introduced air into the cylinder somehow)...... Anyway after I finished installing the brake linnings I had no peddle, had to pump all the time to be able to stop (hairy in traffic!!) ..... I bleed out the back brakes & then had a full firm peddle.... Bob

REDSOXTICKET · 03-25-2005, 08:54 PM

Bmaintz, do you have drums in the rear if so we have different brake systems.

You stated the brakes are firm but do they travel to the floor if you keep pressure on the peddle.

Again, I need to know of a brake system with rotors all around because the hydraulics with ABS is different.

Anyone

THX

Bmaintz · 03-26-2005, 07:28 AM

Drums in back but your pedal should not go to floor under pressure in both systems, hydraulic pressure is FIRM but air can compress.... Bob

REDSOXTICKET · 03-26-2005, 08:13 PM

The pedal is firm (travel about 2 inches) and does not go down at all under foot pressure but only when the car is off.

So your saying there could still be air in the system even if the pedal is firm with the car off ?

Could it be that the firm pedal signifies that the pressure booster is working ?

Rotors all around with ABS.
_______________________

The car on and driving, the brakes engage at the same brake height as with the car off. The car will stop long before the pedal reaches the floor but If I continue to apply pressure it will sink to the floor level minus about half inch or so.
________________________________

THX
Victor

bronzemaxell · 03-26-2005, 10:45 PM

Quote:

Originally Posted by REDSOXTICKET

The pedal is firm (travel about 2 inches) and does not go down at all under foot pressure but only when the car is off.

So your saying there could still be air in the system even if the pedal is firm with the car off ?

Could it be that the firm pedal signifies that the pressure booster is working ?

Rotors all around with ABS.
_______________________

The car on and driving, the brakes engage at the same brake height as with the car off. The car will stop long before the pedal reaches the floor but If I continue to apply pressure it will sink to the floor level minus about half inch or so.
________________________________

THX
Victor

i am awaiting to bleed my brake system as well, and not sure what cause my brake to fail when the car is sat for a while (6 or 8 hrs) in a very cold day or nite.

here is my obervation,
when the temperature is 35F or lower, and the vehicle has been sitting for several hours, step on brake padel to shift to drive, and if i step on the brake padel again to stop the vehicle, the pedal is harden, feel like no pressure, and the vehicle just keep moving forward like there is no brake applied, if i step on step on the pedel again, the pressure build up, engine rpm drops a little as something kick in, and it will work for rest of the trip, then until engine shut off and 6 or 8 hr cold down,

if the temperature is 40-50F or higher, it doesn't have this behavior, work just like normal.
do you guys think the problem with master cylinder, brake booster or air on brake line?

Mike Gerber · 03-27-2005, 12:24 AM

bronzemaxwell,

I don't believe you have air in the lines as this would cause a problem reguardless of the temperature. Check the large vacuum line feeding the brake booster for cracks. The brake booster works on vacuum and this line may be cracked and giving you a slight vacuum leak there. If you don't see any cracks in this line, then my next step would be to get a manual and do checks on the brake booster itself. An old test used to be to shut the car off and then press the brake pedal down 2 times. If the pedal gets hard on the second press of the pedal, then the brake booster is working normally. There might be a more modern test in some of the manuals.

Mike