73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Brakes, Frame, Steering & Suspension => Brakes and Braking Systems => Topic started by: SUX2BU99 on June 24, 2008, 03:15:18 pm
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If I wanted to just do a simple clean of the rear drums on the used rear end I bought, can I just wash it down with brake cleaner? Wash it off with water after or no? I took one drum off and they looked pretty good so I'm not interested in tearing them all apart.
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I, too, am interested in anyone's thoughts on this procedure, Since I just did the same thing (without the water, just brake cleaner)
I just replaced my 3.73 12bolt open diff with a very noisy ring&pinion with my doner truck's 3.42 10bolt gov-lock. My truck brakes are fine and just sprayed off the backing plate and internals with brake cleaner, then did a quick spray pass down each shoe to make sure no grease got left there. Then bolted my brakes to my newly installed diff and never had to disconnect the parking brake.
It is still in the air with the drums off. But i'll be done soon and have a status report.
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I'm interested in your procedure of how you removed the old diff and put in the new one, if you don't mind running it down quickly in point form. I have a plan in mind but I want to see how someone else has done it.
The brake lines on the new diff were all cut, so I know I will have to transplant a couple of items which are no big deal. So are you saying you removed the entire brake assembly, still intact and attached to the backing plate, from your old diff and then simply bolted it onto the new diff? That's an interesting idea. The parking brake cable was also cut but the boneyard guy said you just put a 12-point 1/2" socket overtop of whatever holds the cable one and it releases it really easy?
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The parking brake cable was also cut but the boneyard guy said you just put a 12-point 1/2" socket overtop of whatever holds the cable one and it releases it really easy
Wish I'da known that, my method of working each little tang and finally getting the p-cables out of the donor was less than rewarding.
In point form:
Place some chocks at the front wheels
Using floor jack on diff housing, raise truck high enough to sit comfortably behind the diff cover.
Support with jack stands (6T) at the front of each leaf spring perch. This will let the springs sag a little when you let the diff down. Stay out of the way while lowering! While lowering diff, take the time to tap-set the legs of your jack stands with a hammer to relieve stress from time to time. I am doing this out in the gravel diveway, so I used a long 2x12 under the stands to keep everything close to level and supported.
Set p-brake and Remove wheels.
Unset p-brake and remove drums.
I determined at this point my brakes were just fine.
Cleaned brake assembly as stated.
I am replacing my rear brake hose, so I disconnected the hose up at the frame bracket and then disconnected the lines at each wheel cylinder.
Lower the differential, and get the jack out of the way.
Remove diff cover and remove the pin at the spider cluster. Push in each axle and extract the c-clips then remove axles.
Remove the 4 bolts holding each backing plate and swing each brake/plate assembly down to rest. Put something under them to keep the shoes off of the dirt (in my case, I had 2x12 to rest them on) the p-brake is still attached, no need to remove.
Replace axles, c-clips, and spidergear pin and put the diff cover back on. This will make someone a nice differential one day. All it needs is all new innards :)
Put the jack back under the differential and raise to support some of the weight.
Use a stout pull bar and a 15/16 socket to break loose the u-bolts at the springs. Then rattle off the nuts with an impact. Use a wire brush first to remove dirt and rust off the threads first.
more later. got to go home...
I am back. On to the list...
Once the u-bolts are free, go back and make sure the vent tube is disconnected at the bottom of the bed. Then drop the diff.
Manage to get a creeper under the housing and you can move it anywhere.
Reinstall is reverse, except you dont put the dirt back... ;D
Still in the process of putting everything back, got the backing plates on and the new brake hose and lines, drums. Still need to torque the u-bolts (thinking of getting new ones) then put the new housing gasket on and fill the differential. And I need to put a different u-joint to match the 10-bolt yoke.
I couldn't fine a torque value for the backing plate bolts (fine thread 3/8") so tightened them to 60 ft-lbs. U-bolts are supposed to be 140 ft-lbs according to Haynes.
Later.
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Washing your brakes with brake clean is a waste of money and needless exposure to more chemicals. Use simple green and water. Let them air dry before you put the drums back on.
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Awesome, thanks Vile!
CCZ, I look forward to hearing more!
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I'm having a problem removing one of the drums. It will wiggle a bit but it won't come off. It won't turn either. It seems as though the shoe is engaged. Perhaps the parking brake is 'on'? The other side drum was fine. What can I do about this to get the drum off?
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I'm having a problem removing one of the drums. It will wiggle a bit but it won't come off. It won't turn either. It seems as though the shoe is engaged. Perhaps the parking brake is 'on'? The other side drum was fine. What can I do about this to get the drum off?
Have you tried to back off the shoe adjuster ? Try tapping with a hammer ?
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I had to use a hammer on my donor's drums. Just a couple of light raps at 90deg intervals around the back edge will do it.
When I say light, I mean that if your finger was in the way, it would hurt a little.
I used a 2.5lb beater.
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Take a BFH and strike the drum on the face side a few times to shock it. This will help break the rust.
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I'll try that then. I had my rubber mallet out and was bonking on the edge of the drum trying to loosen it but it wasn't enough. I scraped out a bunch of mud and crud from between the drum and backing plate so I suppose there certainly could be some rust in there, especially if the shoe is sitting very close to the drum. I sure hope that's what it is. Having a stuck shoe I'm sure would really suck to get loose. I haven't touched the adjuster wheel yet. Which way backs it off?
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http://forum.73-87chevytrucks.com/smforum/index.php?topic=5029.0
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Wow, was that ever helpful! Thanks Vile. I've been on this forum when that thread was posted originally but I don't remember it. What Pugsy123 said was interesting because the drum will wiggle about 1/8" if I put a flat screwdriver between the drum and backing plate and try to move the drum. The drum won't turn though so I will try backing the adjuster off. If I'm looking at the backside of the backing plate, do I push on the adjuster at the top or the bottom of the star wheel to back off the shoe? Or, in other words, turn the wheel up, or down?
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Okay, I'm getting really choked here. The drum is stuck on there I'm sure because the brake shoe is engaged. I can wiggle the drum so it isn't rust-stuck. With a crowbar inside the lip between the drum and the flange I can move it 1/8 to 1/4". And when I wiggle it, I can see the cut e-brake cable moving too. The boneyard monkeys cut the e-brake cable and left a few feet of it. So what do I do???? Where are these knock-outs on the backside of the backing plate? I see none. I see some dimples around the perimeter. Are those them? When compared to the drum I have off, those dimples don't line up with the adjustment wheel. HELP!!
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Does the wheel turn freely? If so the brake isn't stuck on. Look in the hole with a flash light. Take a small pocket screwdriver and move the adjuster lever out of the way. then rotate the star wheel backwards. It will wan to click in the tightening direction and lock in the oposite direction. Moving the lever out of the way will allow you to rotate it backwards so the drum will come off easliy. Take a pic so we can see what you have
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No, that's just it: the drum will not turn at all. Not like the other side which turns freely. And there is no hole on the back side of the backing plates. Neither of them have any holes. Are there plugs in the holes? I know I"ve seen these little rectangular holes before but these dont have them :(
Man, why can't anything jsut be straightforward? Do I have the ONLY 81 GM 12 bolt with no bloody window at the adjustment wheel? In that thread you linked to Vile, Pugsy said there might be a stamped area to punch out. There are some dimples like I said around the perimeter but they look pretty thick to punch out. I wacked at one with my crowbar and a hammer and it didn't look like it was wanting to go anywhere.
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I'll have a few pics uploaded in 5 min.
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Face of offending drum. Diff 'snout' is pointing down, for reference.
(http://memimage.cardomain.com/member_images/1/web/3001000-3001999/3001366_3_full.jpg)
Backside of backing plate. You can see on the top right corner where I wacked one of those dimples with my crowbar. Not sure if that's supposed to be a 'knockout' window or not.
(http://memimage.cardomain.com/member_images/1/web/3001000-3001999/3001366_4_full.jpg)
Another pic
(http://memimage.cardomain.com/member_images/1/web/3001000-3001999/3001366_5_full.jpg)
And the other side of the backing plate. No window..... ???
(http://memimage.cardomain.com/member_images/1/web/3001000-3001999/3001366_6_full.jpg)
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Can you actuate the brake cable or is it seized? If it's seized just cut it and force the cable back up in. If it's not take a 3lb sledge (BFH) and smack the drum here
(http://i6.photobucket.com/albums/y228/Sabaka454/drum.jpg)
Picture someone's face you can't stand and smack it hard on the x's. Put some penetrating oil over it too.
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I haven't tried too hard to move the e-brake cable since the diff is a little wobbly on those jackstands. I could try that but will probably get frustrated with that quickly and relegate myself to the BFH :D It's that or I drill myself a few holes in the backing plate to access the adjuster wheel.
Have you ever seen a backing plate with no access slot to the adjuster?? I can't believe it doesn't have one. Do those dimples look like knock-out points?
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they do not look like knockouts, they are what the shoes slide on on the other side.
usually the adjuster access knockout is on the face of the drum, but if the drum won't turn then there's not much point. use the hammer.
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put that thing on the ground and put 2 lugs back on and wedge you crowbar btwn the lugs and see if it will turn with a little extra leverage. dont bend your lugs, though.
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I hate it when you write a long reply and then it disappears >:(
Anyway, I bought a 2.5 lb ball-peen and a can of Liquid Wrench today and went at it. After lots of spraying, smacking and prying with the crowbar, the drum finally came off the fully-engaged shoes. I adjusted them back down so that the drum wiggles just a little bit so I know they are almost seating at rest, but not quite.
Next issue (isn't there always? This is the part I hate about wrenching) is very tight shock mount bolts, brake lines and bleeder screws. I don't want to round any heads off or break anything either like the small and soft brake line nuts and bleeder screws. Suggestions???? Already shot them with LW and the impact gun ain't working on the shock bolts.
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Use a 6 point socket and a breaker bar. Your impact gun isn't going to do you much good on anything rubber mounted. Lines use flare nut wrenches. Try tightening a little bit then loosening. Work it back and forth. Also take a pic of the shoes with the drum off so I can give you some pointers on things to look for.
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Cool, thanks Vile I will do that. Yeah flare nut wrenches are something I do not have so no wonder regular wrenches mess them up. Right tool for the right job, eh? I'll have to pick some up.
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Here's the pass brake setup with drum off. This was the one that was causing me problems. I've moved the assembly around and the springs seem to work well. I plan to wash off both sides with Simple Green and the shoot on some Liquid Wrench as a lubricant. Oh, and give the inside of the drums a light sanding.
(http://memimage.cardomain.com/member_images/1/web/3001000-3001999/3001366_7_full.jpg)
(http://memimage.cardomain.com/member_images/1/web/3001000-3001999/3001366_8_full.jpg)
So how about these parking brake cables? Is it just a matter of prying all of the tangs apart and them squeezing them back on? I'm not sure how to get this trick of putting a 1/2" 12 point socket overtop to get them to let go. Both sides are different.
Passenger side. It has tangs that end over the top like a claw
(http://memimage.cardomain.com/member_images/1/web/3001000-3001999/3001366_9_full.jpg)
Driver side. No claw here for some reason even though the pic doesn't show the top like the other one does but the tangs don't bend over.
(http://memimage.cardomain.com/member_images/1/web/3001000-3001999/3001366_10_full.jpg)
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>:( >:( >:( >:( Well I gone and done it now, I broke a bleeder screw. Twisted right off in the socket. I got the other one off after figuring out to keep at it with repeated tugs on the socket and it came free. Wish I had a brain and did that the 1st time. Soooooo mad. So am I hooped now and have to take the whole bloody thing apart and replace the master cylinder?? If I can somehow get the remnants of the bleeder out, I can just put in another one.
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just get some new hardware, cables, shoes and wheel cylinders and get the drums turned. Start out fresh and they'll last you a LONNNGGGG time.
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Yeah that would be the best way I'm sure. I'd still have to get those parking cables apart. What's the deal with those?
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Not really sure what you mean? to get them out of the backing plate just squeeze the tangs in and push once you have them removed from the brake lever.
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Oh yeah, I got that part done. But I mean to get them separated because I have to get them apart in order to get my old diff out and the new diff installed into the truck right? I posted a couple pics where it looks like they mate.
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I've done some net searching and while I haven't found any pages yet explicitly about these trucks, every page I've read about removing a parking brake cable say to do it right from the brake assembly. So I guess that means I'm going to have to take the brake assembly apart regardless and the connector I've shown pics of is not meant to take apart?
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I'm not sure what you are asking. If you are removing the whole rear axle just disconnect the cables at the equalizer.
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I posted a couple pics where it looks like they mate
If I remember earlier in this post, you have gotten a complete rear end assembly with the parking brake cables cut, so you need to remove these to put your own on.
The pic shows where the outer sheath connects to the backing plate. You need to now find the end of the inner cable which is attached to a lever on the rear shoe.
The only way to get to that lever and remove the cable end is to disassemble the brakes.
Hope this helps!
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Gotcha, I have to remove it from the shoe itself within the brake assembly. I thought maybe I could disconnect it somehow at the joint/connector that I took pics of but that looks like a permanent joint since it's all crimped together.
So taking apart the rear brakes basically is pulling on the springs with pliers or whatever to get the hooks off? And taking good note how it all goes together.
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And taking good note how it all goes together.
or...
do one side at a time.
or...
have a good picture.
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Yeah I'll just do one side at a time, plus theres the brakes on my truck too for reference. Is it a real pain to yank on those springs to get them to let go or is it relatively easy? Sometimes it can be hard to know how much force you should be putting into something, especially when it's almost 30 years old.
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They make a special tool to walk the springs off real easy, If you plan on keeping the truck for a long time. Less than $20. It also assists in putting them back on, which is the real task.
You can get them off pretty easy with a pair of pliers. Remove the little pins that hold the shoes against the backing plate and the whole shebang will collapse with very little effort and the tension will be off the springs.
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Cool, thanks very much to you and to Vile for helping me out so much with this. I appreciate it! I'm sure I'll be back with more questions.
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btw, your truck looks way better than mine.
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Use brake spring pliers
(http://evergreen-rentals.com/images/brakespringpliers.jpg)
and a hold down spring tool
(http://www.bencostuff.com/images/tools/285_4.jpg)
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Yep, that's it. I lost mine years ago, but they were really handy. Here's what I used for both tasks:
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Right on, I'll look around for those tools. A good investment I'm sure.
Thanks for the compliment on the truck. I bought it mostly the way it is now but have done improvements here and there.
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Ya know what's disgusting? I have a Canadian Tire (big sports/auto/home/seasonal chain in Canada) and a UAP/NAPA outlet right near my office. Price out the brake spring tool. Can Tire: $14. NAPA: $31 :o Jegs: $4. Price out the hold down tool: Can Tire: $12.50 NAPA: $14 Jegs: $3 ??? Ticks me off......
Oh yeah, I couldn't find a crowfoot wrench except at NAPA and paid $9 for a 3/8x7/16 single wrench >:( So dumb.
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I got the wrench thing figured out and vound a vendor who had reasonable prices on them.
I've taken apart the pass side brake and took a ton of pics. Fighting against the tension of the springs was the most difficult part. Partially reassembled it just so I can get practice at it, and then bought new shoes, springs and wheel cylinders. Not all of the hard parts come with the new stuff so I'm going to be wire brushing and repainting those pieces.
So in trying to take a wheel cylinder off, I've got a frozen bolt. This diff is just seeming to fight me all the time. Drum wouldn't come off, and then busted a bleeder screw and now this. The other bolt came off with some fighting but it relented. This one won't. I've hammered at the wheel cylinder to loosen the rust and on the bolt head. My 6-point socket is rounding off the edges and the bolt head is fairly mangled. So what can I do? Still try and twist it off, or should I just drill the bolt out?
The bolt passes thru the backing plate into the cylinder thankfully so drilling the bolt out and destroying it and the bolt threads in the cylinder is no big deal since I have replacements. I've never drilled out a bolt before so I should find a drill bit closest as I can to the diameter of the bolt shank, punch a center in the bolt head with an awl, and then just go at it?
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pound a socket on there and snap it off. I have plenty of brake tools if you need them I will give them to you.
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Hey, thanks for the offer! Both the pliers and spring tool have both been great advice so far. And I got that bolt off. I did like you said and just pounded a socket on there. I guess it gripped better than it did before getting mangled because the bolt came free! Now the trick is getting the socket off the bolt, but my vise, a punch and a hammer will fix that.
I got the bare backing plate all wire brushed and will coat it with Chassis Saver, then reinstall the new parts. Progress is being made. Then comes the drivers side...... lol
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Here is an excellent link I found. Actually, on some automotive forum somewhere somebody said to check autozone for DIY links. I did and found the best info yet on doing rear drum brakes:
http://www.autozone.com/addVehicleId,1237304/initialAction,repairGuide/shopping/repairGuide.htm?pageId=0900c1528004c85c
If the link doesn't go straight to where it's supposed to, choose the truck you want, engine size of whatever, and then choose Brake Shoes under Drum Brakes to get the full info and diagram.
Question though, in my Haynes manual for my 03 Tahoe, it says to lubricate the friction areas on the backing plate with hi-temp grease to keep the shoes moving freely. The autozone link did not say this. Should I?
Oh, and I've touched the shoes with my bare hands. Do I need to clean them with Brake Kleen now?
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Well I went out today while I had the chance and got a little tube of hi-temp thread sealant, hi-temp silicone brake system lube and a can of non-VOC brake cleaner.
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Just keep the linings free of grease. Lube the lands on the backing plate with either white lithium or moly lube. Just a small amount.
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Cool, thanks. I'll spray off the shoe faces too since I was touching them with my bare hands just to be sure.
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spray a little on a rag and wipe them off once you have them all done and adjusted up.
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Well I was successful last night in actually getting the entire passenger-side brake assembly reassembled! I'm sure the drivers side will go way faster now. I had one partial snag though. There is a spring that goes vertically from the parking brake level up to this little 3-side thing that the actuator rod/link connects too. The Autozone instructions didn't reference it, nor did their blow-up diagram but it's in the pictures. I couldn't get the lower hook entirely seated into the hole. It popped out on me a few times but this last time it held. It's not as secured as it was before though.
Here it is originally. It's the spring that's just to the right of the hold-down spring (http://memimage.cardomain.com/member_images/1/web/3001000-3001999/3001366_20_full.jpg)
Here is a shot looking up. See how nicely seated the hook is into the hole? (http://memimage.cardomain.com/member_images/1/web/3001000-3001999/3001366_21_full.jpg)
And here it is after reassembly. The hook isn't going into the hole very well and it can't really rotate either. Is this thing even needed? (http://memimage.cardomain.com/member_images/1/web/3001000-3001999/3001366_26_full.jpg)
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That spring will keep the adjuster in position to adjust the brakes when you tap the brakes in reverse. You need it.
It is not in there right. Put it in the bottom hole first oriented just as it is with the pigtail end seated correctly (further in the hole), then get a long screwdriver or your spring install tool against the tang where it will finally go and lift. The spring should just snap in place.
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Okay, I'll try that then. The 3-sided thingamabob was pressing up right against the shoe so that's why I didn't do it in that order but I'll try it out again and hopefully it will work right for me.