Quiestion about brakes on 96 Camry - Toyota Nation Forum : Toyota Car and Truck Forums

Fabito · 12-30-2008, 08:51 PM

Hello,

1996 Camry, 2.2L, 4-cyl. Manual.

Here's the thing, I was driving around my neighborhood, doing about 25-30mph on normal weather conditions, when my brake pedal went straight to the floor with little pressure nearing a stop sign, as the pedal was already as far as it would go, I tried pressing harder (as I was freaking out) and it came to a screeching halt. I managed to get home somehow, I have not been able to take it to my mechanic because I can not afford a tow and havent found a mechanic to go to my house already charging me to just go.

I have only tried bleeding the brake lines and master cylinder. I have bleed them about 4 times, there is new brake fluid on the whole brake system. I used this manual to learn how to bleed the lines: http://www.**********s.com/camry/br.pdf (complete repair manual: http://www.**********s.com/camry/ ).
I'm getting no resistance whatsoever on the brake pedal with the engine off and on.

My question is:
What do you fellows think is the problem? I don't think its air in the lines, and the pads are not that old. I wish to be able to fix it myself. Any ideas, I would greately appreciate it. Or if I bleed the lines wrong, I would love to be corrected.

Thanks for you help.

***toyomoho*** · 12-31-2008, 12:08 AM

Have you checked the brake front calipers, rear cylinders and all lines for fluid leakage. Check the front flexible lines running to the caliper for swelling when braking. Check the brake system for damage that would allow a hydraulic piston in the caliper or cylinder to have a longer travel.

The brake system is just a hydraulic system. The master cylinder supplies the fluid pressure via the brake lines to move the pistons in the calipers and cylinders.

If all OK would suspect a bad master brake cylinder. A bad seal can cause the piston inside to fail to build fluid pressure. No pressure and the pedal goes to the floor.

Fabito · 12-31-2008, 12:14 AM

I checked the lines for swelling and leaks, also checked the tires for wet spots, as far as i could see, they were ok with no leaks. I will check the caliper and drums tomorrow with daylight. I've read about not pressing the brake pedal to fast while bleeding, I remember my dad doing just the opposite, hopefully it didn't cause any more damage.

Thanks. btw, its non ABS.

JCamry94 · 12-31-2008, 12:50 AM

Run your fingers up the brake line to check for leaks. Mine did that and I had to order a new line!

Also you can check the master cylinder pretty easily on the i4 engine you have since you got some open space down there, so check that for leaks as well.

***new echo owner*** · 12-31-2008, 01:20 AM

Was the fluid at the proper level before you bleed the system? Did it change any at all after the bleeding?

N.E.O.

Fabito · 12-31-2008, 10:25 AM

As far as I could see with broad daylight, there were no leaks in the hoses, I will check again with my fingers and a flashlight just to be sure. The fluid level was about 1/8 inch below full but above low before I started bleeding (and made sure it was at the right level when bleeding).
When I press the brake with the engine idling, 1 out of 10 times I get some resistance as it would normal.

***new echo owner*** · 12-31-2008, 06:58 PM

Sounds like you may have internal leaking by problem with your master cylinder. Did someone help you to bleed the brakes?

N.E.O.

JustinC25 · 01-01-2009, 09:52 AM

Master cylinder may be leaking into the brake booster.

Jimnist · 01-01-2009, 11:16 AM

No resistance at all?

Not even when you slam it on really hard, really fast? If you do (have resistance/pressure on the pedal), like NEO said, it could be an "internal" leak. Ive never heard of it on a car, but it happens on bikes sometimes. I don't remember exactly, but again, like Neo said, it was in master cylinder. Something about a seal, possibly o-ring getting dislodged and letting fluid past.

Fabito · 01-01-2009, 01:19 PM

Today I plan to take off the master cylinder and inspect it. I have a camry repair book that tells me how. I will check seals and gaskets. Hopefully thats all. Thanks a lot.

My dad helped me bleed the master cylinder, however the instructions were pretty vage when it came down to the end.

Unhook the likes
Press the pedal slowly
When the pedal is down, block the line holes and release the pedal.
repeat.
However, when do you hook the lines back up? while the pedal is down? or when the pedal is up? I hooked them up after we released the pedal.

***new echo owner*** · 01-01-2009, 05:10 PM

Are you talking about bench bleeding the master cylinder before installing it? Or are you bleeding after it has been installed?

N.E.O.

Fabito · 01-01-2009, 08:05 PM

Quote:

Originally Posted by new echo owner

Are you talking about bench bleeding the master cylinder before installing it? Or are you bleeding after it has been installed?

N.E.O.

I'm talking about when I bled it the first few times right after the problem surfaced.

That brings me another question, how do I bleed it when it install a new one? same way?

***new echo owner*** · 01-01-2009, 09:38 PM

If you are talking about just bleeding the brakes system, you shouldn't have to bleed it at the master cylinder. The sequence should start with RR, LR, RF, LF, have someone pump the brakes for you if you are just using a hose to bleed the system. Connect one end of the hose to the bleed valve, and submerge the other end to a container with some brake fluid in it. Pump the pedal a few times and then hold it down, open up the bleed valve and let the fluid out. When the pedal goes down to the floor, tighten the valve. Do this on each wheel a few times, keeping an eye on the fluid level in the master cylinder. Always close the valve with the pedal down, but with the hose in the container with fluid there is less chance of air re-entering the system.

To bleed the new master cylinder, you can bench bleed it, by clamping the master cylinder down with a vise, fill the reservoir up first, then just let it gravity bleed for a little bit until you see fluid coming out of the ports. Then cover the ports up with your fingers or buy a kit to re-direct the fluid back into the reservoir. You can bleed it further to get all the air out but it does get messy if you don't have any means of re-directing the fluid back into the reservoir. Or you can use the pedal in the car and the lines as a means to finish bleeding the M/C. Mount the M/C in the car, snug the lines down while holding the pedal to the floor. Then pump the pedal a few times, crack the lines loose to let the air out. Do this until you have a firm pedal. Then go through the bleeding process above for all wheels.

Others may have different ways of doing this, I use this way when I don't have my vacuum bleeder with me.

N.E.O.

donbryce · 01-02-2009, 09:53 AM

Quote:

Originally Posted by Fabito

My dad helped me bleed the master cylinder, however the instructions were pretty vage when it came down to the end.

Unhook the likes
Press the pedal slowly
When the pedal is down, block the line holes and release the pedal.
repeat.
However, when do you hook the lines back up? while the pedal is down? or when the pedal is up? I hooked them up after we released the pedal.

If you did what the above tells me you did, you actually unscrewed the brake line flex hoses at each wheel, or completely removed the bleeder screws? The procedure is to turn the bleeder screw on the caliper just enough to allow fluid/air in the line to 'squirt' out as the pedal is depressed, then immediately tighten it in to close it. You're trying to pump all the air out of the lines/calipers/master cylinder (air can be compressed) and replace it with brake fluid (which doesn't compress, transferring pressure from the master cylinder pistons to the caliper pistons).

Edit: OK, I read the procedure you quoted, and noticed that they start by giving instructions on bleeding the master cylinder in the case where the fluid level had dropped below minimum, allowing air into the master cylinder. Did you undo the lines at the master cylinder first, before bleeding at the wheel cylinders?

Fabito · 01-02-2009, 01:04 PM

Quote:

Originally Posted by donbryce

If you did what the above tells me you did, you actually unscrewed the brake line flex hoses at each wheel, or completely removed the bleeder screws? The procedure is to turn the bleeder screw on the caliper just enough to allow fluid/air in the line to 'squirt' out as the pedal is depressed, then immediately tighten it in to close it. You're trying to pump all the air out of the lines/calipers/master cylinder (air can be compressed) and replace it with brake fluid (which doesn't compress, transferring pressure from the master cylinder pistons to the caliper pistons).

Edit: OK, I read the procedure you quoted, and noticed that they start by giving instructions on bleeding the master cylinder in the case where the fluid level had dropped below minimum, allowing air into the master cylinder. Did you undo the lines at the master cylinder first, before bleeding at the wheel cylinders?

Yes I bled the master cylinder first, then hooked the lines back up and then bled the lines, like you said, by turning the plug just enough, however more fluid came out of some tires than others FR and RL had the most fluid come through the hose.

Today finally planing on bleeding the lines again before taking off the master cylinder. And checking the pistons and gaskets.