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Old 05-08-2013, 08:49 PM   #1
Maladd
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Brakes engage when trying to back up?

Hi all, I have a problem backing up. The transmission does engage, but I can't back up..it's like the brakes are engaged. I have no trouble going forward.

My truck is manual drums all the way around.

Could this be some type of problem with the self adjuster?

Jeff
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Old 05-08-2013, 08:58 PM   #2
DnHolland
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Re: Brakes engage when trying to back up?

Have you had any brake work done lately, or did this just start happening out of nowhere? Having your primary and secondary shoes on backwards could cause this. It could also be a misadjusted self-adjuster.
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Old 05-08-2013, 10:35 PM   #3
Maladd
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Re: Brakes engage when trying to back up?

I've redone everything on the chassis, and I'm definately no mechanic. I was very sure to put the shoes on the correct sides.

That being said...I wouldn't have even 90% confidence in anything I did myself. I do remember that on one of the back brakes, the self adjuster was pointing the wrong direction (according to the haynes manual), but I put it back together like the repair manual showed. I have no idea if it was working right before or not since the vehicle I got the chassis off of was not running when I got it.


Jeff
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Old 05-08-2013, 10:38 PM   #4
Maladd
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Re: Brakes engage when trying to back up?

Also, the way the adjusters were before I rebuilt were one side was "pointing" towards the rear, and one to the front.

Now they both "point" the same direction, but can't remember for certain off the top of my head. I believe the cap is towards the rear on both of them. Believe the front brakes are set up the same, but ran out of time to look at them today.

Had a massive air bubble in my cooling system and focused on that first.

Jeff
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Old 05-08-2013, 10:46 PM   #5
DnHolland
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Re: Brakes engage when trying to back up?

On drum brakes you want to associate everything front and rear, not left and right. The primary shoe has a smaller brake pad area than the secondary. The primary shoe should always face the front of the truck. If the self adjuster is installed correctly it should have a lever that can contact the star wheel.

I made this mistake years ago I replaced the brakes on an old F-200. I put the brakes on the same way they came off and they didn't work. Turns out whoever did it before put them on wrong and I just copied them.

I wish I had some pictures to show you. If I can find some I will post them here. If you have a chance, take some pictures of what you have and label them front/left, front/right, etc. so we can take a look at what you have. That may be the best way to get the help you need.

By the way, left is always driver's side and right is always passenger side.
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Old 05-08-2013, 10:49 PM   #6
Maladd
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Re: Brakes engage when trying to back up?

Yeah, I'd love to shoot some pictures tomorrow and have them verified as correct...or not. Was the first time I worked on drum brakes in over 20 years.

Strangely I ended up with no warm memories, just an idea to save up for a conversion LOL.

Jeff
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Old 05-08-2013, 10:59 PM   #7
DnHolland
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Re: Brakes engage when trying to back up?



Maybe I did this right.

In this picture the front of the truck would be on your right, so this is a passenger side set up(it will be a mirror image for the driver's side).

I found this on google so it's not an exact match but it will work.

You should have a lever that comes down from the secondary shoe and hang over the 'star' wheel of the adjuster. When you apply the brakes in reverse, the servo(rotating) action of the brake shoes cause the lever to come down, turning the star wheel. Thus, self adjusting the brake shoes as they wear.

Hopefully the picture shows up, and hopefully that helps you diagnose your problem.
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Old 05-08-2013, 11:01 PM   #8
DnHolland
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Re: Brakes engage when trying to back up?

The picture didn't show up. Apparently I'm better at replacing drum brakes than posting pictures. Post up some pics of what you have and we'll go from there.

Converting to disc would solve your problem, though.
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Old 05-09-2013, 04:49 PM   #9
Maladd
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Re: Brakes engage when trying to back up?

It looks like I mistook the trans going in to drive for reverse and wouldn't move. All gears except park are currently Drive, and can fell it wanting to move forward when starting the truck.

Think I probably lost that little S hook on the internal linkage of the TH350. I had to replace the shift rod last week and bet I didn't get it back together just right. Think it's going forward in all gears and the parking rod is only thing keeping it from running forward while it's in park.

I had noticed last night while burping the transmission that the engine seemed to bog after giving it some throttle.

Thanks for all the help though :-)
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Old 05-09-2013, 09:04 PM   #10
Maladd
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Re: Brakes engage when trying to back up?

Nut had backed off and the S had fallen off. All is well now :-)
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Old 05-09-2013, 09:46 PM   #11
DnHolland
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Re: Brakes engage when trying to back up?

Glad you got it fixed.
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Old 05-12-2013, 07:16 AM   #12
wraprail
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Re: Brakes engage when trying to back up?

Quote:
Originally Posted by Maladd View Post
Yeah, I'd love to shoot some pictures tomorrow and have them verified as correct...or not. Was the first time I worked on drum brakes in over 20 years.

Strangely I ended up with no warm memories, just an idea to save up for a conversion LOL.

Jeff
Don't worry, they haven't changed in the last 20 years.

I guess you were saying you don't really have a brake problem?
As unsure as you seem maybe it would be a good idea to pull the drums and take a look.
For your safety? (and everyone else on the road.)

One quick way to check if the adjusters are in backwards might be to look in the adjustment slot on the backing plate. You should be able to see your star wheel in the hole.

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