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Brakes lockup when braking hard in reverse


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I've searched through the threads and haven't found anything specific to my issue... please forgive me if there is and just haven't found it.

 

I have read that braking while in reverse will help to get sticky drums to adjust.

 

Well, yesterday I tried this technique, and while I admit, I hit the brakes really hard (not slam, but harder than normal) I found myself with locked brakes all-around. After 2 or 3 pumps of the pedal, the brakes would release and everything would go back to normal.

 

Any ideas? Thanks!

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the first part of your issue seems like simple physics... the brakes are designed to work best when moving forward... and since the front discs will grip better they'll lock up when the weight is taken off of them because of moving backwards... and the angle of the vehicle would cause the drums to do the same thing...

 

however, you say that the brakes remain locked until you pump the pedal a few times? so if you try to move after braking hard backwards you can't go anywhere because the brakes are still locked up?

 

could be that the self-adjusting mechanism caused the drum shoes to dig in really hard...

 

I have to agree with grossgary... don't do that, and get rear discs... (:

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Lets define what hard breaking is. The self adjusters are basically a ratcheting mechanisim. There is a primaryt and secondary (leading or trailing ) shoe. BY backing up your causing the trailing shoe to become the leader, and due to the way the self adjuster cable is routed, this works the self adjuster. You dont have to break all that hard to get them to work. They will even adjust when driving normally. I suspect that your break hardware (springs) are tired and need replacing. Any issues with self adjusters can usually be traced to tired springs.

 

 

nipper

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If you have clutch, you probably just set the hillholder.

 

it isn't supposed to operate on level or downhill slopes, but backing up and stopping suddenly makes the check ball roll to the back of the valve, just as if pointed uphill.

 

The brakes probably released when you let off the clutch to get the car to drive, and you coincidentally thought it was the *pumping* of the pedal that made it go away.

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If you have clutch, you probably just set the hillholder.

 

it isn't supposed to operate on level or downhill slopes, but backing up and stopping suddenly makes the check ball roll to the back of the valve, just as if pointed uphill.

 

The brakes probably released when you let off the clutch to get the car to drive, and you coincidentally thought it was the *pumping* of the pedal that made it go away.

 

NICE HIT! good call.

 

how many of the old gen had hill holders anyway?

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Since '80 or '81, all of them. Up until hydro clutches in 97
well, not that this is related at all, but i thought huck said his 93 FWD impreza EJ18 didn't have it? maybe the extra weight was too much for the EJ18? :lol: pardon the tangent.
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i thought huck said his 93 FWD impreza EJ18 didn't have it?

 

That would be news to me. All the MT 90-94 Legacies and the first 2 years of Outbacks had them.

 

I work on fewer Imprezas than any other subaru besides *rare* models like SVX, XT6.

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Once again, I am humbled by the overwhelming level of expertise on this board. Often times its difficult with my noobishness to even post a seemingly dumb thing such as this. But fortune favors the prepared mind, and I am prepared to be embarrassed in order to learn.... many thanks!

 

To answer your question Spiffy, no, can't move forward or backwards after braking hard. Pumping sets it free... but Gloyale makes a good point regarding attributing it mistakenly to another solution.

 

So I took a look at both rear drums, and the springs look good, in fact new-ish.

Gave everything a good cleaning, and incidentally, eliminated an annoying rubbing sound by removing a hardened clump of dirt/dust/rust from the groove of the backplate assembly, woohoo!

 

So OK, point well-taken, I will not do that again.

I do intend to switch to discs for the rear, but my budget will not allow that to happen for a while (planning & saving for a Weber swap).

 

Boy do I want to try to replicate this with hill-holder disconnected... but I won't:-\

 

Thanks again all!

"USMB keeps my Soob alive" - my future t-shirt idea...

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