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]

More useful information about my problem:

I took your advice and started by taking out the slide pins on the mounting bracket (torque plate) of the right front caliper.

The bottom slide pin, the one with the rubber bushing, was extremely hard to remove (surprised me how hard I had to work to get that sucker to come out). Once out, I could see that the rubber bushing had swelled. I had used a little packet of grease that I, now, can’t remember where it came from, so suspect it was that grease that caused the rubber to swell.

You can see the swelled bushing on page two of:

http://s1273.photobucket.com/user/GuiermoVilla/library/

If these two images don’t clearly show it, I measured the bushings with a micrometer and determined that the one that swelled was 0.024” larger than the extra one I had left over.

I cleaned off the old grease on both slide pins and applied Sil Glyde, which advertizes that it is good for caliper slides and can “stop slide sticking, and ease rebuilding of rubber parts: o-rings, grommets, boots, and seals boots against moisture.” After putting both pins back in, both were easily manipulable by hand, moving in and out easily.

Then I got inside the car and pumped the brakes a few times, hoping to get the calipers to set up around the rotors, and then tried to use the breaker bar and socket to turn the right rotor, thinking that I might have fixed the problem. No such luck. . . the rotor was very tight and hard to turn, making a bad scraping noise from the short turns I applied.

Then I looked carefully around the rotors and discovered that the back side of the rotor was running extremely tight against the back side of the mounting bracket, and either the bracket or the top rear pad support plate was scraping hard against the outer back edge of the rotor, causing the last quarter inch to the edge to be a little damaged.

I decided to put the front tires back on and drive the car around in my driveway and short street to see if it was acting any better, or if the problem was the same as yesterday. The problem is now different. It is no longer cyclical. It gets loud when I make left hand turns, but I can hear a little of it when turning right as well. During a left hand turn, there is a constant loud scraping noise. When driving straight, it almost goes away.

Since it was starting to rain, I put her back in the garage and decided to make this report before taking another step. I do plan on opening up the left side caliper pins to put Sil Glyde in them as well, because I suspect the other side will have the same bushing swelling going on.

NOTE: I don't know how to place images in these posts. Help me.

drums suck. next time i need to change mine i'm swapping them out for discs.

What do you feel it is about drum brakes that make them suck?

Second Issue: the thin metal dust cover plate may be slightly bent and rubbing the rotor, just bend it a bit with your hand.

I bend it nearly everytime I work down there...

This post has been edited by Langing: May 16, 2014 - 11:05 AM

[mkernz22]

drums suck. next time i need to change mine i'm swapping them out for discs.

What do you feel it is about drum brakes that make them suck?

Discs are newer technology and they are a lot better than drums.
Working on drums is a pain where as discs are very simple.

[Langing]

drums suck. next time i need to change mine i'm swapping them out for discs.

What do you feel it is about drum brakes that make them suck?

Discs are newer technology and they are a lot better than drums.
Working on drums is a pain where as discs are very simple.

Thanks, I believe what you say is correct. My brake rebuilding project forced me to learn how both types work (my 94 has rear drum and front disc). Though they are somewhat Rube-Goldberg in comparison, the drum brakes didn't seem all that hard to understand or put together, however, initially getting the drums off took us about two hours, trying to figure out how to stick two screwdrivers in a little hole in the dust plate into the darkness and turn a thingy to unstick the shoes, according to a diagram I didn't understand. And, assembling them must be somewhat non-intuitive because I made at least two assembly errors which required taking parts back off again. Still haven't got the parking brake right. Had one side with its shoes reversed from the other rather than a mirror image.

The only thing I found difficult with the discs, other then getting the exact concept down, was figuring the proper way to lubricate the slider pins. Used a grease at first that caused the rubber bushing on the lower pin to swell, locking the pin in place. I would have never found that problem except one guy read my comments and told me my problem sounded exactly like his. Without his comment I don't know how long it would have been before I found that stuck pin, and I know it would have worn one of the pads far faster than the other.

So, my experience pretty much verifies what you said. As far as disc brakes being a lot better. . . well, the entire auto industry is almost finished changing over to all four wheels having disc brakes. Drum brakes have been around since the beginning, and it has taken quite a while for the newer and better technology to take over. The reason for the slow changeover, I feel, must be related to the issue of dealing with the parking brake.