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Old 02-12-2015, 11:39 PM   #1
treveiger
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69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

I recently did the brakes on my 69 C20 with the HO52 full floating rear end. I decided to do a walk through of what I did so people can use this as a reference. I took several pictures throughout the job to hopefully better explain how I did it. If there’s anything people want to add please do as this was my first(and hopefully last) time working on full floaters.

I got started by looking through my 1969 Chevrolet Truck Chassis Service Manual and the forum( www.67-72chevytrucks.com ) to help get a idea of what I was getting into. The sections in the Service Manual I used were:
· Axle Shaft-5200 and 7200 Lb. Axles (page 4-25 in Rear Suspension and Drive Line)
· Hub and Drum (page 4-26 in Rear Suspension and Drive Line)
· Section 5 Brakes (I basically used this as a picture reference of the ones that looked like the drums I was working on)

Step 1. Removing Axle

First you need to support your truck with jack stands and take off the tires. Once your done with this you will see your Hub/Drum Assembly. The Hub/Drum Assembly is pressed together through the lug bolts so it will come off as one unit. In order to get the Hub/Drum Assembly off to service the drum brakes you need to take the Axle Shaft out. To remove the Axle Shaft you need to take out the 8 bolts you see in the below. There will be a small amount of gear oil that will come out so be prepared to catch it in a container.
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Old 02-12-2015, 11:41 PM   #2
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

Once you remove the 8 bolts the Axle shaft should be now free to come out. If its stuck the Service Manual says to use two 1/2"-13 bolts in the threaded holes provided in the axle shaft flange. By turning these bolts alternately the axle shaft may be easily started and then removed from the housing.(Quoted from the Manual). Personally I just pressed on the Axle Shaft Flange and the seal broke free so I was able to pull out the Axle Shaft in the pictures below.
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Old 02-12-2015, 11:43 PM   #3
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

When pulling these things out try to support them as best as possible, there not too heavy.

The picture below is the part of the Axle Shaft that goes inside the rear end(sorry I don't have any pictures of the whole Axle Shafts), these beasts are about 4ft long.
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Old 02-12-2015, 11:45 PM   #4
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

Step 2. Hub/Drum Removal

First thing you need to do to remove the Hub/Drum Assembly after removing the Axle Shaft is disengage tang of nut lock from slot or flat of locknut.
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Old 02-12-2015, 11:55 PM   #5
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

Then remove locknut from housing tube, using a special Axle Nut Removal Tool. You can rent the tool at Advanced Auto Parts. (I do have a picture but it wont let me post it right now.)
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Old 02-12-2015, 11:57 PM   #6
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

The Axle Nut you remove will look like the one above. It’s a little bugger getting out with the special socket but it is doable. Next the Nut Lock will slide on out and will come out like the picture below.
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Old 02-12-2015, 11:59 PM   #7
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

After the Nut Lock is out there is another Axle Nut that you need to remove just like the one before, use the special socket to remove it.
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Old 02-13-2015, 12:03 AM   #8
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

Once that Axle Nut is out you need to remove the washer that is in there. A dental pick would work nice but I just slid the drum forward a little then back into position and I was able to grab the washer and pull it out.
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Old 02-13-2015, 12:06 AM   #9
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

The picture above is also the orientation, Axle Nut, Nut Lock and Washer. That will be the order that they will need to go back in. Once all that is done the Hub/Drum Assembly SHOULD slide off, if it does not the shoe might be pressed against the drum. If this is the case you will need to back off the adjusting screw inside the drum through the little slot at the bottom of the drum and back off the shoe in the drum to get out the Hub/Drum Assembly. Take caution in taking these off the axle as these are heavy. Once the Hub/Drum Assembly is off you will should see the picture below.
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Old 02-13-2015, 12:10 AM   #10
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

Step 3. Drum Brake Assembly Removal

Next you will need to take the Brake Drum Assembly apart, take caution as these springs are under tension and have the potential to hurt someone if not careful. I will just post pictures of the disassembly steps that I did as I wouldn’t know how to exactly explain it, and it will also be good for a memo when putting things back together.
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Old 02-13-2015, 12:17 AM   #11
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

Some More
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Old 02-13-2015, 12:22 AM   #12
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

and more
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Old 02-13-2015, 12:28 AM   #13
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

and more
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Old 02-13-2015, 12:31 AM   #14
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

annnd more
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Old 02-13-2015, 12:36 AM   #15
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

Once the brakes are disassembled you will have the choice to replace the wheel cylinders or just use your old ones. For me I bought new ones at Napa. For the price the security of knowing they were new was worth it for me. To remove these are quite simple although you will need to bleed the brakes as you have to disconnect the brake line but bleeding brakes are a simple quick process that is good to learn anyway. To remove the wheel cylinder there are two bolts on the back side of the wheel cylinder that will need to come off(sorry forgot what size they were), then all you do is disconnect the brake line and the wheel cylinder will come off. To reinstall just do what you just did in reverse and hand tight until snug, DO NOT OVER TIGHTEN.

Step 4. Brake Assembly Reassembly

Now that the disassembly is over with, all that there is left is the reassembly. I did not have many pictures of this process as my wife was helping me because the springs were quite stiff and hard to stretch. Once again please take caution and wear gloves for this process because if caught right these springs will rip your hand wide open or worse.

Take note that the E-Brake components are gone, my E-Brake was stuck and worthless so I just decided to toss it as I never use it. Do this at your own risk...
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Old 02-13-2015, 12:38 AM   #16
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

Step 5. Hub/Drum Reassembly

Once you have all off your springs and shoes back on you’ll need to put back on your Hub/Drum Assembly. My Hub/Drum assembly was in good shape still so I just took them into a local machine shop to have them turned. I also replaced the inner Hub seal as shown in the picture below. To remove pry old seal from its location in the hub bore, using care as not to damage bore surface. Thoroughly clean all oil and foreign matter from seal contact area in hub bore. Pack the cavity between the seal lips with a high melting point wheel bearing lubricant, and position seal in hub bore. Carefully press the seal into the hub bore, using appropriate tool until seal is properly seated(I used a wood 4x4). Once you install the inner hub seal carefully install the Hub/Drum Assembly. Once the Hub/Drum Assembly is back on you’ll need to install the washer that was in Step 2. Hub/Drum Removal then follow the Hub Bearing Adjustment in Step 6.
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Old 02-13-2015, 12:42 AM   #17
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

Step 6. Hub Bearing Adjustment

Before checking bearing adjustment, make sure brakes are fully released and do not drag. Tighten inner adjusting nut to correct specified torque (50-60 Ft. Lbs.) at the same time rotating hub to make sure all bearing surfaces are in contact. Next install tanged nut lock against the inner adjusting nut. Align inner adjusting nut so short tang of nut lock will engage nearest slot on inner adjusting nut. If it is necessary to rotate the adjusting nut to make tang align correctly, rotate the adjusting nut slightly clockwise for barrel roller bearings(up to 1/8"). Install outer locknut and tighten to correct specified torque(175 Ft. Lbs.). Then bend long tang of nut lock over into slot of outer nut. This method of adjusting will result in the proper bearing loading, and wheel should turn freely.

Step 7. Drum Brake Adjustment

For this step all I did was adjusting the star lever in that little slot on the drum brake on the front until I started to feel a slight drag then stopped. The first picture is the star lever that adjusts the brake. The second is the slot on the front of the drum(left side of drum)that you’ll need to use to adjust the star lever.
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Old 02-13-2015, 12:48 AM   #18
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

Step 8. Axle Installation

To reinstall the axle you will need to thoroughly clean both axle shaft flange and the end of the wheel hub. The note in the book states the “any lubricant on these surfaces tends to loosen the axle shaft flange bolts”. After cleaning, place a new gasket over the axle shaft and position the axle shaft in the housing so that the shaft splines enter the differential side gear. Position gasket so that holes are in alignment and install flange-to-hub attaching bolts. Torque the bolts to the specified torque(90 Ft. Lbs.). Another note in the book is “to prevent lubricant from leaking through the flange holes, apply a non-hardening sealer to bolt threads”. I also put some gasket sealer on the gasket to prevent any leakage. Make sure not to use too much thread sealer or gasket sealer or it may be forced out as the bolts are installed.
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Old 02-13-2015, 12:53 AM   #19
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

few more
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Old 02-13-2015, 12:55 AM   #20
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

After that you need to install your tires and that’s it. I hope this information helps someone because I was new to drum brakes and full floating axles but its really not hard. If there is anything anybody would like to add/ask please do.
Also, sorry for the multiple posts. Thats the only way I could get the pictures to where they needed to be.
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Old 02-13-2015, 11:01 AM   #21
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

Hello,

This is a very nice write up, I just did this process about 1 month ago. Couple of questions:
-->I'm assuming you had to separate the hub from the drums to have them turned. How out of spec were the drums? One of mine was 1/4'' larger in diameter than the nominal.
-->What fluid did you use to fill the rear diff to make up for what was lost during the job?
--> What do you mean when you say "Take note that the E-Brake components are gone, my E-Brake was stuck and worthless so I just decided to toss it..." From the picture it looked like every thing was in place. What did you toss?

Thanks!
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Old 02-13-2015, 11:14 AM   #22
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

Very nice write up. Thanks for sharing.
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Old 02-13-2015, 12:05 PM   #23
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

This is great.. I did this work on the same rear end about 6 months ago.. (although I made couple of mistakes along the way!) This will def help someone in the future...
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Old 02-13-2015, 02:27 PM   #24
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

Quote:
Originally Posted by Duluth67 View Post
Hello,

This is a very nice write up, I just did this process about 1 month ago. Couple of questions:
-->I'm assuming you had to separate the hub from the drums to have them turned. How out of spec were the drums? One of mine was 1/4'' larger in diameter than the nominal.
-->What fluid did you use to fill the rear diff to make up for what was lost during the job?
--> What do you mean when you say "Take note that the E-Brake components are gone, my E-Brake was stuck and worthless so I just decided to toss it..." From the picture it looked like every thing was in place. What did you toss?

Thanks!
I asked my machine shop and he said not to separate them he'll just do it with them together. As far as wear on them in not sure. He just said they were in good shape.

A trick I did was jack up the side that your working on a little higher then the other side to reduce the amount lost and repeat on the other side. I use only Ams Oil in my toys and I'm pretty sure its the severe gear 75w-90.

I got rid of the cable(kinda hard too see unless you see it in person) on the outside of the back plate of the drum. I'm sure soon I'll probably redo the ebrake but as for now it works fine.
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Old 02-13-2015, 02:47 PM   #25
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Re: 69 Chevy C20 HO52 full floating rear end drum brake removal/installation.

nice writeup. The only thing I would say is you dont need an axel nut remover. A screwdriver and hammer to break it loose worked fine for me. once its loose it spins right off. Of course torquing it back on is kind of a guess with the screwdriver method
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