Need expert advice on finishing 94 Celica brake job Options

[Langing]

JULY 22 UPDATE: "BRAKE JOB" FINISHED. (See comment of today's date.)

JUNE 2 UPDATE: REAR BRAKES FINE NOW; FRONT RIGHT STEERING KNUCKLE DEFINITELY BENT (AT THE EARS); SEEKING ANOTHER KNUCKLE.

MAY 28 UPDATE: NOW WHAT? THE REAR WHEELS ARE LOCKED BUT THE PB IS DOWN! WHAT THE HECK IS GOING ON?

MAY 27 UPDATE: SATISFIED THAT THE REAR DRUM BRAKES ARE NOW FUNCTIONING PROPERLY; PROBLEM DEFINED DOES NOT AFFECT THE BRAKE AT ITS PROPER ADJUSTMENT OPERATING POINT; MOVING ON TO NEXT TASK

MAY 23 UPDATE: REAR DRUM BRAKE PROBLEM DEFINITION IS NARROWING SUCH THAT AN EXPERT MIGHT BE ABLE TO HELP ME (SEE LAST POSTS)


This is my first experience doing such an extensive job on my Celica, and I have the Green Books (FSM). Everything looks beautiful (to me), have photos.

I have finished replacing/rebuilding all parts of the brake system -- meaning at all four wheels (including new hardware, hoses, wheel bearings, etc) and am ready to put her back on the road, but . . . with all new shoes, pads, drums and rotors, how can I know they are working properly? I’ve already discovered a couple of assembly mistakes I had to correct, which tells me there may be something else I am missing?

First known issue: because I don’t have a vernier caliper longer than 6”, an AMPRO T71558 Brake Drum Resetting Gauge will arrive on Friday so I can set the ‘clearance’ between the shoes and drums at the rear. Beyond that I have some confusion on how the parking brake works to maintain the proper clearance, given the initial setting of the rear brakes. I want to be totally clear about what I am doing so I am not making a stupid but costly mistake.

For example: the manual says to verify that the parking brake levers (on the rear shoes) turns the adjusters (they do) and then to minimize the length of the adjusters (I did), then install the drums and pull the parking brake lever (in the cabin) all the way up until a clicking sound can no longer be heard (did that as well). The very next procedure is to check shoe clearance, but the last step left the parking brake on? And I was thinking that engaging the parking brake and then releasing it was the cause of the adjuster turning, and that it turns only by just one gear tooth distance. All that said, the manual has me just setting the initial clearance, popping on the drums and tires I'm good to go. Is that really all I need to do to make sure the rear breaks are functioning properly?

Second issue: with new rotors and pads on the front disc brakes, there isn’t a lot of free space in the caliper bracket and there is a scraping sound when I turn the rotors by hand, so there is obvious interference. I don’t know whether the slide pins are not working well, since the calipers aren’t sliding in and out when hand manipulated, or are they just supposed to rub together until enough friction material wears off that they can begin to have enough space to work once the car is on the road? How do I check them BEFORE I put her on the road, so I can be certain they are working properly?

My inexperience has me ready to go, but dead in the water.

This post has been edited by Langing: Jul 22, 2014 - 11:06 AM

[Langing]

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