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Drum Brake Questions!!!

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Old Sep 16, 2009 | 11:19 PM
  #1  
mustangcat's Avatar
mustangcat
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Default Drum Brake Questions!!!

Hey guys.

Really need your help on this one. A very cute girl I know wants me to help her with her truck on Friday. I like this girl, so help me help her!

It's a 1990 Chevy 1500 pickup. Drum brakes.
She says when she went to pressed on the brakes the other day, nothing happened. The truck has been parked since.

1) Could it be her brake fluid is low? Do drum brake systems have a fluid reservoir under the hood like disc brakes?
2) If it's leaking, will there be signs outside of the drums, or will I have to remove the drums to find leaking?
3) Any other assumptions?

Thanks lads!
Old Sep 17, 2009 | 12:22 AM
  #2  
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67mustang302
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Drum brakes work mostly the same as disc brakes, they just use shoes, springs and drums instead of pads and discs and calipers. Could be leaking, if the fluid is low then where did it go? Leak. Might need bleeding, shoes could be glazed/worn etc etc.
Old Sep 17, 2009 | 12:55 AM
  #3  
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Originally Posted by 67mustang302
Drum brakes work mostly the same as disc brakes, they just use shoes, springs and drums instead of pads and discs and calipers.
That is incorrect. While disc and drum brakes serve the same PURPOSE, they operate in completely different WAYS. The drum brake system uses shoes that are pushed outward into the drum. The disc brake system uses pads that are clamped onto the rotor.

On to the problem. When you say nothing happened- I'm assuming you mean that the brakes didn't work at all- thus, the pedal is to the floor. If that's the case, than it is most likely a leak. HOWEVER, if it could also be air in the lines, or a bypassing master cylinder.

Believe it or not, the basic brake system hasn't changed much at all, and still relies on the master cylinder pushing fluid to the calipers and/or wheel cylinders for movement. There will also be a brake booster located behind the master cylinder that adds braking assist (it's a vacuum operated setup with a hosing running from the intake).

GOOD LUCK WITH THE GIRL!
Old Sep 17, 2009 | 07:54 AM
  #4  
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That truck will only have drums on the rear. Go check all the same basic things like you would on any car. Check for leaks, fluid level, pad/shoe wear.
Old Sep 17, 2009 | 08:00 AM
  #5  
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If there is a leak at the rear, check the wheel cylinder, top dead center of the drum. Typically, they are the first to go when there is a problem in the rear. Though, I doubt it is that because when brake fluid leaks into those shoes, it likes to grab and lock the wheel up while the brakes are depressed, not the opposite. A 1990 truck most likely will have brake line rust, check the cylinder reservoir to make sure she has fluid, if not, there is a leak and a line has blown out somewhere. Otherwise and hopefully, she just has worn brake shoes and they need to be replaced. The springs can be difficult, I like using a good set of pistol grip needle nose pliers to grab and pull them. When installing the springs, wear eye protection. Should the needles loose grip as you are pulling, they will hit your face, ask me how I know. Other than that, have fun and post pics of said female lol.
Old Sep 18, 2009 | 01:39 PM
  #6  
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Thanks for the assistance guys!

Looked at the truck today. No leaks, plenty of fluid. She said the brake pedal felt "super stiff" almost too hard to push down. And it doe's it every once in a while, but not all the time.

I suggested that she bleed her brake fluid since both the front brake pads(disc like JD said) had plenty of pad left.

Any other ideas of what might be going on?

-MC
Old Sep 18, 2009 | 01:43 PM
  #7  
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Check to see if the caliper(s) may have froze.
Old Sep 18, 2009 | 01:44 PM
  #8  
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Is it possible that the calipers froze then unfroze?
Since it doesn't do it all the time, just some time.
Old Sep 18, 2009 | 04:12 PM
  #9  
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67mustang302
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Check the power booster and lines, it may have an intermittent leak.
Old Sep 18, 2009 | 04:12 PM
  #10  
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Maybe the brake booster.

Edit: ^how the F man! but yes check for a leak.
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