Rear Brake Disc/Parking Adjustment Options

[trdproven]

Are there any adjustments that need to be made if you put on a new caliper I noticed these celicas use a duo servo mechanical drum parking brake design, where the cable goes into from behind the rotor vice externally. is the only rear parking brake adjustment in the center glove only? I keep reading you adjust something in the rotor first and then move on to the adjustment in the center glove. is that an adjustment in the rotor where that rubber plug is? I noticed when I looked into the rubber plug, its not very clear what to adjust there, the toyota service manual is not very detailed. it says to adjust something so that pads basically lock the rotor, the description sounds like drum brakes but it was listed under disc brakes and drum brake shoes had its only paragraph. Just wondering if anyone knew. I'm used to the hondas rear brake set up.

This what the manual says:
Disc Brakes
Raise and support rear of vehicle. Remove rear wheel. Release
parking brake. Remove adjustment hole plug from rear rotor. Turn
adjuster until parking brake shoes lock rotor. Back off adjuster 8
notches.

This post has been edited by trdproven: Jul 7, 2012 - 2:56 AM

[krom8]

Stick a flat head screwdriver in there. It's adjusted in an up or down motion. A picture is worth a thousand words. In the picture it's the part at the bottom of the picture next to the lithium grease.

Here's a picture from autozone

Adjusting this will actually move the shoes in or out. I own an st so I don't have rear discs but I'd say that the inner shoes on your discs work in a similar fashion the rear drums do on an st.

This post has been edited by krom8: Jul 7, 2012 - 3:51 AM

[trdproven]

Ill take a look again, i know how drums are, but i did not see anything that can be adjusted in there, I couldnt grab anything with the screw driver earlier.

[trdproven]

So again, i just changed my rear brake calipers.

#1. I noticed if I grab my wheel with handbrakes on, my car can move about an inch back and forth before the hand brakes lock the wheel, is that normal? It’s the same thing when I tighten the wheels with a breaker bar it moves about an inch then locks allowing me to tighten my lugnuts. Isn't it supposed to be tight from the beginning meaning already the wheel does not spin? In other cars, they are already locked so can't say for sure whats normal.

#2. Also when I have the car lifted, with handbrakes not on (released), I can spin the tire each about a good spin 10 times, is that normal drag for brakes? Should it be less spins? I noticed it being less on other cars when I try to get ideas but comparing.

#3. I also noticed that the drag sound from the pads sounds a bit inconsistent on the right side from the left side, the left side sounds more like consistent drag which should be the normal one. The right side seems like a skipping dragging sound, not a constant whooshing sound.

#4. Is there some type of adjustment inside the rotor? I noticed there is a rubber plug that when you remove, there is a hole to see inside the rotor. But I do not see anything to adjust. Toyota manual says the emergency brake is duo-servo, not sure what that means, but the cable runs to just behind the rotor, the manual says to adjust something but I don't see anything in there. For the handbrake when I pull up according to the manual says it should be between 4-7 click when you pull up, that’s about what I get, so I guess that adjustment is still ok. So I am still not sure if I still need to adjust anything inside the rotor.

Just wanted to see if anyone had some ideas just so i can try out from your experiences and if anything make my problem solved faster. If not, I usually troubleshoot here and there when I have time and they get solved anyway over time, but I appreciate any extra info.

This post has been edited by trdproven: Jul 8, 2012 - 1:20 AM

[azian_advanced]

#1. I noticed if I grab my wheel with handbrakes on, my car can move about an inch back and forth before the hand brakes lock the wheel, is that normal? It’s the same thing when I tighten the wheels with a breaker bar it moves about an inch then locks allowing me to tighten my lugnuts. Isn't it supposed to be tight from the beginning meaning already the wheel does not spin? In other cars, they are already locked so can't say for sure whats normal.

that's normal. the parking brake shoes have some rotation that allow the wheel to turn a little.

#2. Also when I have the car lifted, with handbrakes not on (released), I can spin the tire each about a good spin 10 times, is that normal drag for brakes? Should it be less spins? I noticed it being less on other cars when I try to get ideas but comparing.

that also sounds normal to me. after replacing the brake shoes, the wheel was able to spin about 6-8 times depending how hard i turn them. there shouldn't be any drag by the shoes when the handle is released
.

#3. I also noticed that the drag sound from the pads sounds a bit inconsistent on the right side from the left side, the left side sounds more like consistent drag which should be the normal one. The right side seems like a skipping dragging sound, not a constant whooshing sound.

could be warped rotors.

#4. Is there some type of adjustment inside the rotor? I noticed there is a rubber plug that when you remove, there is a hole to see inside the rotor. But I do not see anything to adjust. Toyota manual says the emergency brake is duo-servo, not sure what that means, but the cable runs to just behind the rotor, the manual says to adjust something but I don't see anything in there. For the handbrake when I pull up according to the manual says it should be between 4-7 click when you pull up, that’s about what I get, so I guess that adjustment is still ok. So I am still not sure if I still need to adjust anything inside the rotor.

duo-servo means there are two pistons pushing against the brake shoes. that's how drum brakes are usually set up (example). but in the celica's e-brake setup (example) there are no pistons but it's still set up that both shoes push against the rotor. there isn't anything else to adjust besides the star-wheel at the bottom and the nut for the cable at the handle.

[Galcobar]

The rotor has a hole in it large enough to stick a flathead screwdriver through. This is different from the two bolt holes which you can use to push the rotor off of the hub. The hole in the rotor should be lined up with the largest hole in the face of the hub to allow access to the adjuster wheel.

Once the rotor is in place, turn the rotor so that the access hole is at the bottom. This will allow you to catch the adjuster wheel.

Temporarily install two or three lug nuts to ensure the rotor is properly positioned on the hub.

Turn the adjuster and expand the shoes until the rotor disc locks. With a flathead screwdriver in the wheel, move your hand down to expand the shoes, and move your hand up to pull the shoes back.

Return the adjuster eight notches.

Now you can adjust the position of the parking brake lever. Four to seven clicks of the lever should produce full engagement, requiring 796 N (44.1 lbf) of force. If otherwise, you must adjust the relationship between the lever and the cable.

To do so, remove the centre console. Loosen the top lock nut, then adjust the lower nut until travel is correct. Torque the lock nut with 5.4 N–m (48 in.–lbf) of force.

The last step is a repeated road-speed adjustment -- the parking brake is self-adjusting.

Drive the vehicle at about 50 km/h (30 mph), then with the parking brake release button pushed in, pull on the lever with 88 N (19.8 lbf) of force. Hold the lever and drive the vehicle for about 400 meters (0.25 mile), then release. Repeat two or three more times -- once or twice is probably sufficient if neither the rotor nor shoes are new.

This post has been edited by Galcobar: Jul 8, 2012 - 3:27 AM

[trdproven]

#1. I noticed if I grab my wheel with handbrakes on, my car can move about an inch back and forth before the hand brakes lock the wheel, is that normal? It’s the same thing when I tighten the wheels with a breaker bar it moves about an inch then locks allowing me to tighten my lugnuts. Isn't it supposed to be tight from the beginning meaning already the wheel does not spin? In other cars, they are already locked so can't say for sure whats normal.

that's normal. the parking brake shoes have some rotation that allow the wheel to turn a little.

Sounds good.

#2. Also when I have the car lifted, with handbrakes not on (released), I can spin the tire each about a good spin 10 times, is that normal drag for brakes? Should it be less spins? I noticed it being less on other cars when I try to get ideas but comparing.

that also sounds normal to me. after replacing the brake shoes, the wheel was able to spin about 6-8 times depending how hard i turn them. there shouldn't be any drag by the shoes when the handle is released

**I actually replaced the caliper and the pads, not sure if meaning shoes is the same thing.
.

#3. I also noticed that the drag sound from the pads sounds a bit inconsistent on the right side from the left side, the left side sounds more like consistent drag which should be the normal one. The right side seems like a skipping dragging sound, not a constant whooshing sound.

could be warped rotors.

**thats what i was thinking, but shouldn't I get a weird braking result, like vibrating braking or uneven pad wear? The old pads looked fine. and if I recall it didn't have that sound before just now.

#4. Is there some type of adjustment inside the rotor? I noticed there is a rubber plug that when you remove, there is a hole to see inside the rotor. But I do not see anything to adjust. Toyota manual says the emergency brake is duo-servo, not sure what that means, but the cable runs to just behind the rotor, the manual says to adjust something but I don't see anything in there. For the handbrake when I pull up according to the manual says it should be between 4-7 click when you pull up, that’s about what I get, so I guess that adjustment is still ok. So I am still not sure if I still need to adjust anything inside the rotor.

duo-servo means there are two pistons pushing against the brake shoes. that's how drum brakes are usually set up (example). but in the celica's e-brake setup (example) there are no pistons but it's still set up that both shoes push against the rotor. there isn't anything else to adjust besides the star-wheel at the bottom and the nut for the cable at the handle.

**Gotcha but does the term brake shoes mean the GT's have pads and then shoes on the inside too? Your description sounds like an ST where the drum shoes are in the inside and push up against the rotor from the inside.

The rotor has a hole in it large enough to stick a flathead screwdriver through. This is different from the two bolt holes which you can use to push the rotor off of the hub. The hole in the rotor should be lined up with the largest hole in the face of the hub to allow access to the adjuster wheel.

Once the rotor is in place, turn the rotor so that the access hole is at the bottom. This will allow you to catch the adjuster wheel.

**I saw the rubber plug, looked in there, there was a hole, but did not see anything on the inside that I could adjust in fact, the access hole, seems to follow the rotor hole. Do I need to release the rotor off first to get to the access hole, or i just have to rotate it to the south? No matter what I did, the outer hole and inner hole access seemed to follow each other so Im curious cus I drive it around and the two holes are still lined up no matter the position. I might be thinking that its good so all I have to do now is rotate it to the south to access it.

Temporarily install two or three lug nuts to ensure the rotor is properly positioned on the hub.

**This is what I read, but what does putting lug nuts on do? i was just thinking the lugnuts move with the rotor no matter what.

Turn the adjuster and expand the shoes until the rotor disc locks. With a flathead screwdriver in the wheel, move your hand down to expand the shoes, and move your hand up to pull the shoes back.

**what is being meant by shoes here again? Are we both on pads or shoes? Does the disc brakes have the same adjuster?

Return the adjuster eight notches.

Now you can adjust the position of the parking brake lever. Four to seven clicks of the lever should produce full engagement, requiring 796 N (44.1 lbf) of force. If otherwise, you must adjust the relationship between the lever and the cable.

To do so, remove the centre console. Loosen the top lock nut, then adjust the lower nut until travel is correct. Torque the lock nut with 5.4 N–m (48 in.–lbf) of force.

The last step is a repeated road-speed adjustment -- the parking brake is self-adjusting.

Drive the vehicle at about 50 km/h (30 mph), then with the parking brake release button pushed in, pull on the lever with 88 N (19.8 lbf) of force. Hold the lever and drive the vehicle for about 400 meters (0.25 mile), then release. Repeat two or three more times -- once or twice is probably sufficient if neither the rotor nor shoes are new.

Shoes is being used frequently maybe I do not understand the design or something? Not sure if we are all on the same page, but then again, terminology is confusing me here. but just to know, you have to press in the lever, pull up the handbrake, drive for .25 miles and still have the button pressed in the whole time?

thanks for the help guys! looking forward to clarification first. I'm going to redo the crush washers again, i hate brand new ones sometimes, they seem tough to seal sometimes.

This post has been edited by trdproven: Jul 8, 2012 - 5:27 AM

[Galcobar]

As I've explained and showed you repeatedly in your other thread on brakes, Toyota uses a drum-in-disc design. The caliper is used for regular braking, grabbing the disc with pads. The parking brake uses shoes, applied to the inside of the drum. The rear rotor incorporates both a disc and a drum.

Azian Advanced was kind enough to link you a picture of the Celica's rear brake setup, with the rotor removed. You can see the caliper holding the pads, and the parking brake holding the shoes. That silver cylinder at the bottom with the notched wheel is the adjuster.

When the hub turns, the rotor turns. This is because the rotor is mounted on the hub -- you'll note both the lugs and the centre hub stick through the rotor. The rotor must be properly installed on the hub so that its access hole lines up with the largest hole in the hub. This allows you to access the parking brake hardware, which is behind the hub, even when the rotor is in place. If your rotor is managing to turn separately from the hub, you have sheared off the lugs and are about to have a very bad day.

The point of putting on the lug nuts is to ensure the rotor is properly positioned on the hub. Otherwise, it rattles, and a loose rotor is a bad idea when trying to properly position the parking brake shoes.

And yes, when setting the parking brake shoes you hold the release button down and the lever up, so that the parking brake does not lock into place.

This post has been edited by Galcobar: Jul 8, 2012 - 5:42 PM

[trdproven]

Thats the part that i needed clarification, thanks, sounds like I don't need to worry about this then, since I only changed the calipers, the drum in disc was not affected at all, my handbrake clicks are just about right and the handbrake works correctly. I just thought that there was something else I needed to do.

Thank you and thanks Gerald

This post has been edited by trdproven: Jul 8, 2012 - 7:04 AM

[BonzaiCelica]

what is this style of brake system called. the emergency brake shoes inside of rotor design?

also how can you tell if your rear brake disc are warped on the part that contacts with the shoes. whats the measurement for the inner part of rear disc to know whether the surface area is worn down?

Heres my issue :

the whole brake adjustment is driving me nuts. If one side of the rear parking brake adjustment is not the exact same adjustment as the other, will pulling the hand brake several times bring each side in perfect sync. Since both left and right parking brake cables meet up as one once it comes into the center console?

If Toyota recommends 4-7 clicks max, then how would the shoes not end up touching the inner part of disc and slowing down the vehicle. Im currently at 10 clicks on hand brake that will hold the car in place, and I'm still getting slight drag and noise when i take off from a dead stop. I get slight jolting forward motion (due to shoes touching on certain parts of rotor) if i let the car roll from 10mph to a dead stop. I've put 150 miles on my Raybesto emergency brake shoes.

Looking at my old shoes i don't have any uneven wear on them (which should mean my rotors aren't warped?). I also greased the rear backing plate as I see know one mentioned this here. please help fellow 6gcers!

This post has been edited by BonzaiCelica: Oct 12, 2014 - 2:33 AM

[azian_advanced]

you may need to disassemble your brake shoes to test that your cables aren't seized, and the brake shoes aren't seized with the parking brake shoe lever (example).
i've had the brake shoe lever seize with the shoe before which limited its travel resulting to dragging (wheel getting really hot!) and not properly locking up after pulling the handle all the way.
so i took it apart, cleaned up any rust, re-greased the joints, and put it back together.
everything worked good as new after that.
i even went out to do the other side to make sure i won't have to do it again.

[BonzaiCelica]

yay im glad you showed up. well i just came back from local auto shop and they said i cannot machine them down anymore. I put regular caliper grease on the backing plate, thinking that it would be sufficient. I already knew it wouldn't work very long so I have to take everything apart and put anti-seize grease on the backing plate so that everything is moving freely. This will now be the 3rd time that I take everything apart (ha im getting quicker at this)

the shop also said wait for 500 miles till everything brakes in. its been 200 miles so far since the install.

how do i check if cable isn't seized?? just have someone pull on it from the inside and watch the shoes expand??

This post has been edited by BonzaiCelica: Oct 13, 2014 - 6:16 PM