drum brake problem

[keithy]

hi all,
I was trying to look at the source of the squeaky drum brake today, on my 98 le. Went out, put the car on jack stands, removed wheels and removed one of the rotors. I cleaned the inside of the brake drum, asked a friend to step on the brake pedal and test out the parking brake to inspect the source of the noise. Everything was ok until when I wanted to put the rotor back on. The rotos would not fit! when I removed the rotor, it was easy. Is there anything that I should know to put the rotor back? Please help..........

[mazdaverx7]

you need to back the shoes off. there should be an adjuster poking out of the backing plate. it has a gear on it and you will rotate that gear until the shoes begin to back off and your rotor will fit back on. then install the calpier bracket, pads and caliper and you're golden.

[Mike Gerber]

The gear that mazdaverx7 is referring to is accessible from the front side you are looking at with the brake drum off. (I think he was thinking you have rear disc brakes with small shoes that act as the parking brake.) It is usually at the 11:00 or 1:00 position, depending on which side of the rear you are working on. Take a slotted screwdriver and back the teeth one way or the other until the drum fits back on. This will take a bit of trial and error. To back the teeth off and allow the shoes to retract, you will have to pull the locking bar slightly off of the gear teeth. It will become obvious when you see the gear mechanism. The bar keeps the self adjusting mechanism from backing off on it's own in normal use. You should be able to get the drum back on. Refer to the brake section of the generation 4 manual stickied at the top of the General Camry Discussion Forum, for more detailed instructions with diagrams.

Mike

[Novice_cardude]

Also, if it is he drum-in-disc brake system you'll have to compress the caliper pistons in order to get the caliper back on over the pads. .. That is, if your friend actually hit the brake pedal. if he just pulled the e-brake, it'll be fine.

Or just thump both shoes on the rear back together, and try to put the rotor back on :P That's what I usually do.

[keithy]

mazda, mike and novice,
thanks for the advices. I tried what you guys suggested and it still didn't work. Retracted the gear all the way, still no help. But I "think" I found out what the problem was after working on it for 5 hours straight. The problem is that the wheel cylinder wasn't retracting back to the original position. The reason for it was that after removing the drum, the shoes had nothing to back up to, to avoid the cylinder to over-expanding. When I started the ignotion and stepped on the brake pedal the wheel cylilnder was pressurized, thus expanding both ends to a point when it cannot be retracted back to its normal position(somehting is definately stuck). After several tries, I decided to bleed the system, and boy was I wrong. The wheel cylinder still did not retracted, but instead I now have air in the braking system......
But that's ok for now coz I don't get to use the car anyways.
I think my next step would be to remove all component and not have the shoe to pressurize the wheel cylinder. Might have to try adjusting the colar at the cylinder ends to see if that was the thing that is keeping the cylinder from contracting back to its original state. I will write back tomorrow to tell you guys if I solved the problem. Wish me luck.

again, thanks for all the input.

[keithy]

sorry guys for I am a procastinator. Just could not find the time to finish up my drum brakes earlier. The problem was solved by using a clamp to retract the cylinder. For some weird reason, the cylinder would not retract back to its original position. Took off the shoe and used a c-clamp to "compress the cylinder at both ends gently. And the cylinder did retracted back with little force. Now, all is welll. Flushed the old brake fluid off and used preston synthetic DOT 3 brake fluid. Test drove the car and all looks good for now. Thanks for all the advice and help given.

by the way, for those of you who are planing to bleed your brakes, the size of the clear tube you will need is 3/16" ID. OD dos not matter. I bought those from LOWES for about 14 cents/foot. You will need about 2 ft.

[Stillrunning]

First, calper pistons don't retract when the pedel is released, they just release pressure. It is normal to use a tool to compress the piston back into the caliper if the piston is extended. This is noticable when you put new pads on and have to compress the piston to install the caliper over the rotor. You need to remove some fluid from the master when doing this or it will overrun. Second, the rotor develops a ridge from wear and rust on the outer edge where the pad does not touch. If the caliper is removed it does not hurt to file that ridge a little to allow easier assembly. Third, the caliper slides usually need disassembly, cleaning and re-greasing once in a while. Sticking slides can cause advanced pad wear and uneven braking.

[keithy]

Originally Posted by Stillrunning

First, calper pistons don't retract when the pedel is released, they just release pressure. It is normal to use a tool to compress the piston back into the caliper if the piston is extended. This is noticable when you put new pads on and have to compress the piston to install the caliper over the rotor. You need to remove some fluid from the master when doing this or it will overrun. Second, the rotor develops a ridge from wear and rust on the outer edge where the pad does not touch. If the caliper is removed it does not hurt to file that ridge a little to allow easier assembly. Third, the caliper slides usually need disassembly, cleaning and re-greasing once in a while. Sticking slides can cause advanced pad wear and uneven braking.

ok then, now I am learning. Got some questions for ya.
1. if we compress one cylinder at a time, wouldn't that expand the other three cylinders because the brake system is a closed system?

2. do you have to remove the cylinder, take it apart and regrease it before putting it back on? When I talk to a mechanic, he told me specifically "Not to mess" with the cylinder if my intention is only to change the brake shoes. I disagree with him because in the toyota repair manual, I saw the diagram of the the cylinder and all its components. But I did not want to take any risks due to the fact that I have to get my car moving yesterday.

[keithy]

sorry double post