6G Celicas Forums

Another quetion:

Ok, I set both rear wheel adjusters so I can get the tires to spin slightly over 3X with all of my power.

Pulled up the e-brake full, 9 clicks now rather than the 11 of yesterday, but the lever felt more normal in my hand. I'll have to adjust it to get within the 4-7 click range.

Went to the rear wheels to try to spin them. The left wheel was dead stuck (parking brake works). The right wheel can be moved without much effort (parking brake partly works).

Released parking brake and again tried to spin the rear wheels. They both seemed to spin as much now as they did before.

What does that test say to you?

Since the parking brake had unequal effect at the rear wheels, and the rear shoes seemed to be adjusted about equally, does that mean that the left parking break cable is shorter than the right? Does not the parking brake cable begin at the parking brake as a single cable that gets divided into two independent cables under the car, so the difference in cable lengths would be from the point of bifurcation on to the wheels?

Or, is it more likely there a problem in one of the drum brakes (I did work on the brakes, so that's the more likely answer, right?)? How can I verify this? And, if that is the case, does the test indicate which one is messed up? How can I know? Finally, if this is the case, what is the most likely problem with the brake?

Parking break question:

Adjusted the parking break cable so it reaches top at 6 clicks.

Still have same situation regards the rear wheels. Left side tire will not rotate at all, right side will rotate somewhat, when forced by hand. When I release the PB, both tires spin at what appears to be the identical amount of total rotation as before.

Did a further test. I engaged and released the PB 10 times in rapid succession, expecting that if the right wheel was sensing a 'clearance' greater than 0.024" it might let the adjuster tighten by one click, or so, so the right tire would possibly get more of a brake and I might not be able to rotate that side when the PB was engaged. Failed! I can still rotate right side by hand when the PB is engaged.

Crawled under and inspected the PB cable. It's in very good condition, with no obvious deterioration, despite her 20 years of age (looks reasonably close to new). Can see the single cable coming from the PB lever above, running under the heat shield to the cable splitter, and then see two cables coming out from under the heat shield, crossing one another, one each leading to a different rear wheel.

Assuming I have a problem in one of the rear drum brake assemblies, I would next like to remove the drums and attempt to observe how they are working on each side as my wife slowly pulls up the PB (but she isn't home at the moment).

My question is:

Since the PB works by pulling the PB lever attached to the rear shoes, and does not place forces into the hydraulic system by way of the brake cylinder, I do not believe there is any chance for me to blow the brake cylinders the way I did when I asked my wife to step on the brake pedal when we were bleeding the front brakes while the drums had not been put onto the rear wheels. Let me know if my proposed test isn't a wise thing to do. How else, other than careful observation of the PB operation, comparing both sides, can I determine what is causing the difference between the operation of the PB on each rear wheel?

This post has been edited by Langing: May 18, 2014 - 6:21 PM

Never press the brake pedal when the caliper or drum is off. You wont destroy anything, but you will push the piston out of the slave cylinder/caliper. This would necessitate bleeding the cylinder/caliper until the piston is returned far enough to reassemble the brakes, or if the piston was pushed all the way out the brake fluid would escape and the system would need to be purged of air.
I havent seen a pair of drums disassembled on a 6gc before, I have rear disc. Perhaps you could put the rear end on jackstands and have your wife depress the brake pedal(keep the wheels on). I would be curious to see if the same tire that spins freely when the PB is engaged also spins freely while the hydraulic brake is applied since both systems utilize the same brake shoes. This would determine if the issue was with the drum/shoes or with the linkage of the PB. Just make sure she is lightly applying the brakes, perhaps have her slightly increase pressure until you can no longer rotate the wheel by hand and determine if this threshold is balanced between the two rear wheels

This post has been edited by Special_Edy: May 19, 2014 - 9:09 PM

Roger that. When I first had the brakes reassembled, I decided to bleed the system, starting with the front discs (forgetting that I had not put the rear drums back on) , and asked my wife to step on the brake pedal a few times and hold the pedal down. We had gone through the cycle a couple of times and I was kneeling at the front right wheel, watching the brake fluid flowing out of the bleeder valve, when she asked me what that strange noise was. I asked “what strange noise.” She said it sounded like a burst water balloon, like water spraying. Immediately I rushed to the driver’s side rear, and found the wheel cylinder had blown brake fluid all over the place. Almost all of it went up into and around the wheel well, so I caught it before it destroyed my nice epoxy painted garage floor! So, by experience I definitely understand what you are saying.



That is great advice! Just the kind of help I was looking for. I thought it such a good idea that I enticed my wife to follow me to the garage to try out the experiment before going to sleep (it was after 11 pm, and she leaves for work at 7 am). I remounted the right rear tire, so both rear tires were on and then I asked her to begin pushing on the brake pedal while I tried to spin the tires by hand. We weren’t able to get the brake to hold the rear wheels, which seemed strange to me, until I realized that I still had the caliper and pads of the bad right front wheel off, the other remaining problem. Since the brake was moving the piston (luckily, she was not stomping on the pedal), I figured that was why it wasn’t stopping the rear tire from moving. Since it was so late, I called it a halt so she could get some sleep. But your suggestion was a good, definitive way to isolate the problem down to the brake parts or the PB cable, and I do thank you for the suggestion.

Now. . . my next move this morning is to take the ‘star wheel’ adjuster off the right rear so I can examine it to see if it might be left wheel’s adjuster. Maybe the two adjusters are mixed up.

Check me if I am wrong, but the way I figure it, the adjusters are operated by an actuating arm that moves downward (behind the adjuster screw, when viewed facing the wheel), turning the ‘star wheel’ such that you will see the gear teeth moving upwards whenever it is ‘adjusting’ the brakes (tightening the clearance; expanding the adjuster screw). That is true of both the left and right side drum brakes, the teeth will move upward when the adjuster is operated. Since the adjuster screws are oriented from back to front exactly the same on both sides, one of them must have its threads reversed from the other. They are NOT the same.

I was not aware of this difference when I was assembling the rear drum brakes, so it would have been very easy for me to have gotten them installed incorrectly, and this might explain the erratic behavior I have described. I will check this out today and let you know what I find.

If that isn’t the problem, I will still have time to put the right front wheel back together so my wife and I can run your experiment tonight.

And thank you so much for taking the time to digest my problem and make suggestions. I feel that I am getting very close to achieving success.

When you bleed the brakes, you're suppose to bleed the side that is farthest from the master cylinder then work your way to the closest.

It goes:
Passenger rear
Driver Rear
Passenger Front
Driver Front

Just make sure there is are no air bubbles present in the entire system. There shouldnt be any bubbles in the main lines unless you removed the MC or allowed the reservoir to get low, just in the slave cylinders and calipers, plus the hoses if you changed them.

Yes, I agree with you. Sorry I gave the impression that I didn't know. You see, this little job has turned into quite a project. I have been at this for over a month now, and you don't know that I had already been bleeding the brakes, starting well before the incident I reported, with the intention of pushing as much brake fluid through my system as it takes to eliminate as much residue I possibly could of the old fluid. The brake fluid had not been completely changed out, probably since the car was first purchased, 20 years ago. If I ever get this project finished, I hope to go back and rebuild or replace the master cylinder also, so I will know there can be no (easy to eliminate) source of residue and debris left in my refurbished brake system.

Due to the nature of my project, I've done a significant amount of research about bleeding brakes, including Haynes manual, Toyota FSM, YouTube videos, and other sources. Almost always your statement that you should work your way from the wheel farthest from the MC and end up on the wheel that is the closest to the MC is what is recommended. But notice that, according to this general advice, the actual sequence of wheels that should get bled can, and does, vary by vehicle, depending on how the brake lines are actually run from the MC to the various wheels. So, one needs some knowledge about where the brake lines actually go, once leaving the MC, in order to know the correct bleeding sequence. Many times this can be found in a common repair manual for the vehicle. But that's not the only thing to consider when thinking about your rule. For example, the rule seems about as logically sound as one could ever imagine, but ask yourself the question "Where did the rule come from?"

For instance, for my 1994 Celica, my Haynes manual suggests the sequence be RR LF LR RF, which isn't the sequence you set down. My Green Book (Toyota FSM) only says "HINT: Start bleeding from the caliper the farthest away from the master cylinder and finish at the closest" another case of the rule. Take a look at some sequences:

My Celica: RR LF LR RF
Your sequence: RR LR RF LF
Man in video: LF RF RR LR https://www.youtube.com/watch?v=MfTmlOZbXgs
EricTheCarGuy: LF RR RF LR https://www.youtube.com/watch?v=V5O_pbC8R2E

There are people who just do not subscribe to the rule. The clearest example I know of is Eric the Car Guy, who basically advocates doing the opposite, especially when replacing brake fluid. I believe he is concerned not to take the dirtiest fluid down the longest lines first. Thus, he goes from the closest to the farthest. I've included his YouTube video in the list. He believes that going by the rule, the normal sequence for most cars is RR LF LR RF, again NOT your sequence, however it is the sequence specified in the Haynes manual for my Celica. So, there you have all three issues, a standard rule, a reverse standard rule, and length of individual line dependent bleeding sequence.

My intention was simply to document and make you aware of some "discrepancies" that came to my attention during my work on this project.

And while writing this, it struck me that I now must go down to the garage and trace all of the Celica's brake lines, to see that the Haynes advice is credible.

And before I leave, I want to thank you for commenting. As far as I can tell, you are correct.

Good for me to remember that before I sign off on this project I should go round to all the wheels and do a final bleed, just to make sure.

I wonder if you know how to make sure the Proportioning Valve is free of air? The FSM says when one inspects the fluid pressure to inspect the left front (LF) and right rear (RR) together, and the right front (RF) and left rear (LR) together. When the Haynes manual gives the bleeding sequence RR LF LR RF, does that guarantee that air is removed from the P valve?

Yesterday I removed both drum brake adjusters to inspect them. What I theorized the day before is actually true. The adjusters are different. There is a left side adjuster and a right side adjuster. Unfortunately, mine were not stamped with a L or a R, so I wasn't aware that I needed to be careful where I used each one, and might have installed them incorrectly, but, luckily, didn't.

The best way to see that the adjusters are different is the following photo:



One can easily see the orientation of the teeth on these 'star wheels.' The teeth of the star wheel on the right require a lever arm pushing downward on the right side in order to turn it, and that turning motion will be in the clockwise direction.

Since the adjusters are mounted in the rear drum brakes in such a way that the lever arm is behind the star wheel, the effect, as seen from the front, is that the star wheel teeth move upward when the parking brake is adjusting to expand the length of the adjuster, and thus take up slack produced by the wearing away of friction material.

The star wheel on the right in the photo must be mounted with the left rear brake.

The next photo shows the threads of the two screws that are driven by the star wheels.



It may be hard to tell, but the threads on the star wheel on the top (same one as on the right in the first photo) are reverse threads. That should make sense when considering how the adjuster on the right works on the left rear brake. The lever arm pushes down and turns the star wheel clockwise, but reverse threads turning clockwise will tend to unscrew the star wheel, making it longer to achieve the desired expansion of the adjuster.

There are some other photos of the adjuster that might be helpful located at photobucket:

http://s1273.photobucket.com/user/GuiermoV...rake%20Adjuster

They have titles and descriptions that ought to make the story understandable.

This post has been edited by Langing: May 21, 2014 - 2:59 PM

REAR BRAKE INSTALLATION procedure

In the FSM has 14 steps.



STEP 9: CHECK OPERATION OF AUTOMATIC ADJUSTING MECHANISM

(a) Move the parking brake lever of the rear shoe back and forth to check that the adjuster turns.

[DID THAT, THEY BOTH TURN]

If the adjuster does not turn, check for incorrect installation of the rear brake.

(b) Adjust the adjuster length to the shortest possible amount.

[DID THAT BY TURNING BOTH STAR WHEELS DOWNWARD TILL THEY STOPPED TURNING, THEN BACKED THEM OFF JUST A SMIDGE SO THEY DIDN'T GET JAMMED]

(c ) Install the drum

[DID THAT]

(d) Pull the parking brake lever all the way up until a clicking sound can no longer be heard.

[DID THAT, 6 CLICKS]



STEP 10 CHECK CLEARANCE BETWEEN BRAKE SHOES AND DRUM


(a) Remove the brake drum

How can the drum come off when the PB is engaged fully? Is this a problem with the instructions? Or did they actually want the installer to remove the drum despite the fact that the PB was fully engaged? I've tried it with the PB fully engaged. In fact, I have tried it several times from scratch. Most of the time, I was able to remove the drum using my hands or bolts screwed in from the front would easily pop them off, but a couple of times one drum was stuck on and removing it using bolts might have broken the hold down springs, so I resorted to releasing the PB.

Well. . . think about it, their goal is to set the shoe/drum 'clearance' to 0.024". . . I suppose their way of doing that is by minimizing the adjuster length and pulling the PB full up. If that is how the rear drum brakes are initially set to the proper clearance (0.024 ") then pulling the drums off should be no problem for the installer because there would be a 0.024" clearance between the shoes and the drum, right? That might be correct for the everyday brake job, where some installer is changing out both pair of brake shoes and nothing more, but. . .

Let me remind you that my project was to install ALL new or newly self-rebuilt brake system parts on all four wheels, so the NEW shoes should be at their thickest (OD) and the NEW drums at their thinnest (ID). Then, the shoe/drum 'clearance' (the difference between the THICKEST OD and the THINNEST ID) should be dead on 0.024" IF THERE WAS NO ERROR IN EITHER THE SHOE OR DRUM DIMENSIONS! What's the chance of that?

Let me finish the sub-steps of step 10:

(b) Measure the brake drum inside diameter (ID) and diameter of the brake shoes OD. Check that the difference between the diameters is the correct shoe clearance,

Shoe clearance:

0.6 mm (0.024")

(they show the measure being taken using a vernier caliper).

If incorrect, check the parking brake system.

RIGHT: where is that procedure in the FSM?

I'm using the AmPro Drum Brake Resetting Tool I ordered on-line (less than $20) that is a template with a built-in 0.024" clearance, rather than a vernier caliper, because I cannot afford a 12" vernier caliper:



Using this tool makes the job simple. All you have to do is stick the inside diameter measurement side into the inside of the drum and make sure it is the greatest expansion of the tool, then lock it in place. Turn it over and use the OD measure side to see if the shoe OD is exactly that. Done! Well. . . done, if your shoes are really close to that measure, but no larger.


STEP 11: INSTALL BRAKE DRUM

STEP 12: INSTALL REAR WHEEL

STEP 13: FILL BRAKE RESERVOIR WITH BRAKE FLUID AND BLEED THE BRAKE SYSTEM

STEP 14: CHECK FOR LEAKS



All that said, I am still getting inconsistent results. I intend on doing a little more experimenting, but mostly suspect that the problem is due to my putting all new components on and I have a dimensional tolerance problem. When I get the right front caliper back to working I will try the experiment of using the normal brake pedal to see if there is still a difference since the two systems are independent, as recommended by my good friend above.

One encouraging result: the last time I went through all this from scratch, when I had to release the PB to get the right side drum off, I measured both ODs and found them very close to being correct, except the right side OD was just a little too large. But, get this, I mounted both wheels and spun them by hand. The right side would revolve 13 times before stopping, and the left side revolved 15 times! Call me stupid, but. . . I think that is really encouraging.

This post has been edited by Langing: May 22, 2014 - 11:37 AM

KING'S X


Looks like I was fooling myself when I thought I saw that moving the parking brake lever back and forth caused the star wheel to advance.

THE RIGHT SIDE ADJUSTER DOES NOT TURN!

That puts me back at the first sub-step of STEP 9, which says that

"If the adjuster does not turn, check for incorrect installation of the rear brake."


I took that side apart for the umpteenth time, looked over everything I could imagine might be incorrect. Re-measured the clearance between the shoe and the parking lever, found it possibly slightly too large, so installed a 0.013" shim and put the brake back together again. NADA!!

Spent another hour examining the operation of the levers and the star wheel and comparing the two sides. Finally resorted to pulling up the parking brake again to see if I could detect any difference between the two sides with the PB engaged. . .

AND FOUND SOMETHING

Here is where I need expert advice.

On the left side, the side I presume to be working properly because manipulating the PB lever causes the star wheel to advance, pulling the PB full up causes the PB lever (attached to the rear shoe) to pull forward to the extent that the automatic adjusting lever actually touches the shaft of the hub (or comes damn close). Also, the lowest part of the PB lever touches a finger-like tab that is part of the lower center bracket (the bracket that carries the PB cable on one side and the anchor spring on the other; just above the PB cable running in that bracket there are two finger-like tabs sticking out). The travel of the PB lever is stopped by that tab, and when it is stopped the lever arm of the automatic adjusting lever (the metal arm that does the turning of the star wheel) is standing raised somewhat off the star wheel teeth, in the air.

On the right side, pulling the PB full up causes the PB lever to move out a fair amount, but it doesn't come close to touching the hub or lower bracket finger tab. Instead, it seems to be stopped by another, lower down, part of the bracket, and that holds the PB lever back about a quarter inch, maybe a little more. As a result of traveling so little, the lever arm of the automatic adjusting lever is still resting on the star wheel's teeth. It doesn't get pulled into the air. It's no wonder the star wheel isn't turning!

Next, on both sides I looked very closely at the parking brake cable as it comes into the rear brake area and goes over the lower bracket (beneath the two finger-like tabs) and onto the PB lever, where it attaches at the bottom.

The PB cable on the left side seems taught and centered in its channel in the lower bracket, whereas on the right side, it doesn't seem as taught, and doesn't squarely ride in the center of its channel in the lower bracket. It seems to me that the lack of PB lever travel on the right side is due to the PB lever hitting the wrong spot on the lower bracket, but also it seems that the PB cable might be too long and thus might be fighting with the PB lever. [I am not at all certain of this, so take it with a grain of salt; today I intend on removing all parts from both wheels and carefully examine all parts and the assemblies of them. At that time I will carefully measure the exact length of the cable that is inside the wheel (it bolts on at the back of the backer plate).]

HAS ANYONE EVER EXPERIENCED THIS PROBLEM? IF THE PB CABLE WAS TOO LONG, HOW DO i SHORTEN THE LENGTH OF PB CABLE THAT EXTENDS INTO THE RIGHT REAR BRAKE?

OR

WHAT ELSE COULD BE WRONG?


It might help if you take a look at these photos:

Adjuster photos:

http://s1273.photobucket.com/user/GuiermoV...rake%20Adjuster

Closeups of right rear

http://s1273.photobucket.com/user/GuiermoV...g%20differences

Closeups of left rear

http://s1273.photobucket.com/user/GuiermoV...owing%20problem


This post has been edited by Langing: May 23, 2014 - 8:59 AM

A week ago I met the man (on-line) who amazed me with his video (in Spanish) tutorial about taking apart Celica dashboards. If you haven't seen it, you really ought to spend a little time watching him disassemble his Celica dash completely. You can learn a lot about Toyota secrets of interior parts disassembly. To me, this man is a genius for taking things apart and getting them back together. He has done over 15 dashboards to date, and he paints them. Plus he truly likes to help people solve problems. His Spanish video is at YouTube:

https://www.youtube.com/watch?v=LZ9yYj_0l3U

He did it again in English, which is also good, but the best is the Spanish version:

https://www.youtube.com/watch?v=XJ3A1N4kOHY

Anyway, he said he would help anyone with problems, and I had a real problem with my drum brakes, so I zipped off a request and damn if he didn't spend more than a day helping me figure out what to do with my brake problem. To make the long story short, he recommended that I set the adjuster such that the threaded portion (exposed space = adjuster length extension) was a little less than a quarter of an inch as an initial starting point. And then work from there (trial and error) to home in on the proper initial adjustment. It wasn't long before I had satisfied myself that I had a good initial adjustment set for the clearance between the shoes and the drums on both rear wheels. Actually, the Drum Brake Readjustment Tool from AmPro had come in and I was able to use it to set in the proper clearance so easily with that tool (plus you don't need to buy a 12" vernier caliper to take measurements in order to get a proper clearance of 0.024"), I discovered that it put me in an initial condition for the clearance that produced a little less than one quarter of an inch thread exposed in the adjusters, just like Luis had said and I believe either approach gives the same result. So, I declared victory and moved on to work on the right front disc problem.

Well, according to this gentleman, Luis, what I was dealing with was the difference between OEM and aftermarket parts, and frequently one must make accommodations for this or that deficiency in form, fit or function of a bastard part. When the FSM said to begin with the adjusters tightened to their shortest possible length, it brought out a tolerance problem within the component assembly, but when I started at the quarter inch point, the brakes worked reasonably close to properly.

So, I left the rear, with its tires mounted, on jack-stands. When I last was dealing with them, I could spin the left tire and it would revolve 20 times before stopping, and the right 13 times. They spun freely, with very little drag.

Yesterday, I tried to spin one of them and found it locked, stuck, could not turn it at all. Checked the PB, it was lowered. Tried the other rear tire, and found the same result. Before I tear into them to find out for myself, I want to ask you a question and give you a little time to think about it.

QUESTION: What is my problem?

you know how I solved this problem??
BuY a Damn GT!! I hate drum brakes.

but maybe you've just got the parking brake cable too tight, try loosening it at the cable nut on the parking brake lever.

Correct Answer!

That's exactly what I had planned to do first.

Since you have been so kind recommending where to start, I will use that to trigger getting off my. . . seat and going out to loosen the cable right now.

TX

TX much! Fixed! PB = 5 clicks!

with mine I had it set to about 5-7 clicks and it seemed ok, but then when I was driving down the road it would suddenly start to grab and make this awful noise.
so I loosened and tested it to be sure it was just as tight as it needed to be to hold the car on a hill, and not much tighter

Really? Sounds like I better loosen it a bit more before I get her back on the road. I sure don't want that to happen to me.

Just enough to hold on a steep hill and no more; sounds like sound advice, thanks! How many clicks was that?

Now I have to fix my dial indicator (bought 5 Federal indicators in a single pack on ebay today for $20; used but supposedly working fine; resolution to 0.002 mm = 7.87402e-5 inch) so I can make sure my front disc has little to no run-out. Only then can I get back to checking why my disc was scraping the mounting bracket. Since cast iron can't bend, and I'm positive I didn't mess the mounting bracket to that degree, the orientation of the rotor is all that could possibly be incorrect. But before I discovered the problem, I thought I had gotten the run-out minimized. Tried again today to first measure at the inner ring of the hub and thought my current indicator was sticking (0.0001"), so I took it apart and could not get the bezel back on and can't figure out why. That's when I went to ebay.

Patience, patience, patience. . . is a virtue, is a virtue, is a virtue. . .

I think It may have something to do with how worn the Ebrake shoes are, mine was owned by some kid who liked to do Ebrake Uturns or something.
as long as it holds without pulling the lever All the way up you'll be ok

So, it should hold on a hill with the PB pulled up, but not all the way? I was thinking the PB had to be pulled full up whenever engaged. Hey, thanks for the information. The things you are telling me are very helpful at my current state of knowledge.

As to your buying your car from someone who has driven it somewhat hard -- you mean to tell me that those YouTube videos of crazy kids making turns and U-turns by pulling on the Ebrake are for real? I remember "squealing" my brand new GTO's tires, just to show people I could do it, till I had to buy new tires, but that behavior stopped as soon as I realized the costs. With what I know now, I wouldn't dare, thinking of the harm it might do to the suspension, etc., not to mention a possible crash. Guess when I was a kid I was just as crazy as kids today.

Found a thread that is encouraging:


Keep warping rotors, im really frustrated! Getting warped for the 3rd time (Last Post was in July of 2006)

The initiator was a fellow named eliaz, and he described having severe brake problems that manifest as warped rotors; they could warp in as little as 250 miles!!!

By the end of the two page discussion, someone suggested the possibility of having a bent hub/wheel bearing assembly, the whole assembly bent in such a way that the rotor was not rotating in the proper plane, causing the rotor to be in constant contact with the brake pads, causing the rotor to heat up to a high temperature (what better way to warp a rotor?).