Rear Axle Trouble

[dilvoy]

Hmmm.... That's a good one! I can't really tell from the picture, but is your E-Brake hooked up? That has a large pin and washer like that to hold it to the brake shoe. (Think it is in that hole in the lower-left of your pic) I can't see the rest of the brake system, so I'm not saying that is what it is, but I'm just guessing from the pictures. I wish you luck!

Does that bolt have an "H" shaped head? From picture 1 it looks possibly like a brake cylinder pushrod.

I think that's what it is. It looks like the rear one (upper in the foto) is not in place.

 

[Sgt Hulka]

May all problems be solved thusly... Congrats!

 

[M1009 Fiend]

Here are some better pictures

 

[ragedracer]

I could be mistaken, but I'm about 99% sure that that is one of the pistons off the brake cylinder.

Lemme see if I can find a picture of one.

 

[ragedracer]

Ok, I'm now 99.99% sure after looking at your pics. In your pic, the rod/piston should be where the blue line is in the red circle. It pushes against the shoe. In the other pic I found, it just kind of gives you an idea of what it should look like. It looks like a bolt with a notched oval head.

 

[M1009 Fiend]

Thank you for the pic and conformation, thats what i thought it was after looking at the TM.

Now can i drive with out it for any period of time?

 

[4bogginchevys]

I would not drive it, it can completely fail.....the last little bit of seal holding the fluid in does not have anything to push against and could "pop" the next time you hit the brakes, serious danger....

 

[ragedracer]

Thank you for the pic and conformation, thats what i thought it was after looking at the TM.

Now can i drive with out it for any period of time?

Could you, and get away with it? Maybe.

If it were my, I wouldn't. You could end up losing all your fluid if a seal breaks, and then it would be rather difficult to stop.

If it were me, I'd just run down a junkyard and find one of the little pushrods/pistons.

 

[kenny]

Ok, I'm now 99.99% sure after looking at your pics. In your pic, the rod/piston should be where the blue line is in the red circle. It pushes against the shoe. In the other pic I found, it just kind of gives you an idea of what it should look like. It looks like a bolt with a notched oval head.

YEP thats what it looks like and the rear brake shoe look wore out. The only time those pop out is the brakes being wore out.. or the drum is wore out or the brake way out of adjustment.

I would replace the shoes, wheel cylenders, get new hard ware/spring kits and turn the drums.

About 75 to 100 dollars should get you another 75 to 100 thousand miles.

 

[kenny]

How many miles are on your truck?
I am glad it is not your rear end that you have to change.

 

[M1009 Fiend]

According to the odometer i have 86,800 or something.

Ok so no driving for awhile.

So junk yard for new piston rod, then new shoes, wheel cylinder, hardware....
Am i missing anything?

 

[M1009 Fiend]

About 87,000 according to my odometer.

What is the best way to know if the breaks are wore out??

What is the correct brake shoes size, and search only got me more confused?

 

[Cucvnut]

just tell them at auto zone you need stuff for a 86 k5 blazer

 

[burbn10]

About 87,000 according to my odometer.

What is the best way to know if the breaks are wore out??

What is the correct brake shoes size, and search only got me more confused?

Measure the inside diameter of your brake drum and also measure the width of the brake shoes that are on it now. That is usually the best way to determine which setup you have.

 

[Crash_AF]

Better yet, take the old shoes in with you, compare them to the new ones in the box. Ask for the biggest ones that you can get for a 1984 K5. Or have them cross the GM number in the TM

The new wheel cyl may or may not come with the rod... I'd check first before you go scavenging. Also, NAPA might have new ones rather than having to find and clean up old ones.

I have found that rear brake adjusters rarely do their work to a satisfactory level so when I rotate my tires, I pull the drum and clean and lube the adjuster before tightening the brakes up. I figure half the work's done already with the tire off, why not spend the extra 5 minutes per side and make sure the rear brakes are doing their job.

Later,
Joe

 

[burbn10]

Better yet, take the old shoes in with you, compare them to the new ones in the box. Ask for the biggest ones that you can get for a 1984 K5. Or have them cross the GM number in the TM

The new wheel cyl may or may not come with the rod... I'd check first before you go scavenging. Also, NAPA might have new ones rather than having to find and clean up old ones.

I have found that rear brake adjusters rarely do their work to a satisfactory level so when I rotate my tires, I pull the drum and clean and lube the adjuster before tightening the brakes up. I figure half the work's done already with the tire off, why not spend the extra 5 minutes per side and make sure the rear brakes are doing their job.

Later,
Joe

I agree with the adjusters. Use a good lithium or silicone grease that won't wash away quickly. GM recommends lithium grease. I think new adjusters are like $10 from Advance Auto Parts.

 

[4bogginchevys]

I use synthetic wheel bearing grease in the adjusters, and have never had aproblem with the adjustment that should occur when you backup. I make it a point to back into my driveway, sometimes it's easier to back into a parking space at the store, and if the pedal feels a little weak i'll back up and down my street on a saturday hitting the brakes like mad...lol. It ends up as less time spent with things taken apart, and it's easier on the knees than kneeling on the garage floor.