Im trying to find an online reference for a 93 full size Blazer rear brake system. Whoever owned the truck before me apparently replaced the rear brake shoes and put the self adjuster pawl on incorrectly which allowed the shoes to wear far beyond their intended limits which caused the piston to "hyper"extend and blow a seal. Now that I have all the new parts ***embled up to the point of ***embling the pawl, I cannot figure out how it is supposed to be properly ***embled, unless its missing a part. The reference that I have now does not give an accurate depiction of its ***embled state. Is there an online reference for this or can anyone help me with this in any way? <!-- / message -->
If I'm understanding you correctly, you should be able to merely flip the adjuster around 180 degrees and make it work. There is a sort of triangle shaped bracket that has a small tang/arm/stickingoffpiece that will just lay across the front and above the adjuster, so that when you depress the pedal and the wheel cylinder expands, the spring that runs from the one side of the adjuster to the other shoe will cause the tang/arm to pull down on the adjuster, spreading it out. Do you have to remove the drum to manually adjust the pre-load on the shoes, or is there a sight window in the back to run the adjuster tool/flatblade screwdriver into to hit the adjuster? If it does, and the 'star' portion of the adjuster isn't within that window, then its on backwards. This is why whenever I do drum brakes I always leave one side intact (or do one side at a time) so that I always have a reference to check. Some don't think this far ahead, and it seems that the previous 'mechanic' didn't think that way either. Another way to do it is to use the digital camera. Works like a charm too!
Thanks Greg, I will check the other side but am thinking that if he screwed up this side, the other is probably the same. Also, I only have one jack and no jackstands, otherwise I would have compared the two already. The adjustment wheel is in the upper center of the ***embly and you do have to remove the drum to access the adjuster. I'll check what you said about the pawl placement this evening and reply then. Thanks again, Greg, you've been very informative.
Try this, there are two types of systems on these......one is the "dual servo" the other is the "leading-trailing shoe" setup. This picture is the leading-trailing setup, most common on these. This would be the left side, the front of the vehicle would be to the left. Hope it helps ya!
It would stand to reason that if one side were screwed up, the other would be as well. However, you'll be able to at least see what the completed ***embly looks like and reference to the other side. Something you should first pick up though is a set of jack stands. They aren't very expensive - Harbor Freight has a pair on sale this week for $12 - and are cheap insurance against having a load fall on you. Not to mention that in this type of situation, the ability to see both sides of your rear end (sounds bad, doesn't it?) at the same time would be well worth the added expense. Jacks fail, so safety should be paramount. In the above picture posted by Retrorod, the arm thing I was talking about is shown as #11, and the star wheel it contacts is shown as #10. To make sure this setup is working properly, just do a sort of 'dry run' with the tab (#11) against the star wheel (#10) to make sure they are working correctly. When the brake shoes expand against the drum, this tab should create a motion that will expand/unscrew the adjuster. If it isn't expanding, but rather screwing inward, then it is on backwards. This is probably what happened to your setup as done by the last mechanic.
Sweet! That pic does it for me...I'm missing the pin/screw/bolt listed as #12 in the illustration. The guy before me had the pawl attached to the shoe retention spring thingy listed as #8 which caused the pawl to sit about 1/8 in off the aduster which, I believe allowed the adjuster to run out beyond its limits. Do ya'll think I could use a small bolt, nut and two washers as an adequate fix? Thanks for all ya'lls help. Id be ****ed if ya'll hadn't helped.
you can buy all that hardware at most parts stores. Usually in the Help! section. That way its done right. Also, make sure the drums aren't worn oversize.... that can exacerbate the problem
Autozone has some online repair guides that may help. Here's one page from the 93 Blazer section: http://www.autozone.com/az/cds/en_us/0900823d/80/12/b8/68/0900823d8012b868/repairInfoPages.htm Look around in the other areas too. HTH
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