Rear Brakes Tutorial/How To

[zardiw]

Hey all. I had to do the brakes on my truck, and after I started, I thought I'd document the procedure.....then I went a little overboard.....lol.........:

http://www.lighthouse57.com/brakes.htm

z

[wyldman]

Good job,very nice.

Only problem I see is you used anti-sieze on the wheel cylinder piston extensions,which could damage the wheel cylinder dust seal.Anti-sieze and rubber don't mix well.

There is also no need to use silicone on the axle shaft gasket.Most are soft metal,and the viscosity of the fluid is so thick,it will never leak.The silicone makes removal a pain next time,and it can get into the bolt holes (blind thread),and crack the hub when the bolts are tightened.

[Bob Van]

zardiw,

First, Welcome to "The best site around".

My brother runs a brake shop and we just did the rears on my truck, (98 2500 GMC), Monday.

Dealer did the rears about 5000 miles ago (under warranty) due to wheel cylinders leaking. According to the dealer, they replaced the cylinders, seals and shoes. The problem was while backing and trying to stop, they would lock up or thump and grab.

Only left front shoe showed wear, leading us to believe wheel cylinders were not working properly. We replaced shoes, wheel cylinders and hardware.

Working fine now.

Your pictorial was excellent. Even greased and lubed everywhere you did.

We just didn't have the time to make them as pretty as yours.

Again, Welcome to the site!

[zardiw]

Hey....Thanks.....good to be here. I wasn't sure about the anti seize on the cylinder rods either...how about lithium grease? I'll change the pages to reflect these corrections. Thank you for pointing them out...........good ol feedback is GOLD.........z

[76chevyman]

I wouldnt put any kind of lube on the wheel cylinder rods (I would put anti-sieze anywere theres metel to metel contact. those rods are metel to ruber so i wouldnt put anythere)because the lude will hold in any dirt and in turn i would say it works in to the seal putting little ters in it then it causes a leak so i would leve it dri. But thats only my opion. Great right up though.

Rich:burnout

[wyldman]

They don't really need lubrication in there,but if you want to put something there,it should be a proper brake lubricant,usually synthetic based.Use brake lubricant on any parts that touch rubber,and anti-sieze on everything else.

[zardiw]

I've made the changes on the site. Thanks again.....z

[Oldcarnut]

I'm doing my 83 C3500 Dually and when I pulled the brakes apart one of the oil seals in the back of the drums was installed facing one way and one the other (both were leaking slightly). Im not sure which side of the seal goes toward the bearing (inside). Since we're holding the oil inside the hub should the open side of the seal face in? What I mean is, the rubber is formed right to the face of the metal part of the seal on one side and it's not on the other. My wonderful GM shop manual just says put the seal in, no illustration or anything.

This is too much work to guess and be wrong.

Thanks,

John W.

[zardiw]

Ok, this is a crude drawing, but it shows the idea of how a seal is supposed to work.......

http://www.lighthouse57.com/Pictures/Brakes/SealPic.jpg

I would think that the open area on your seal faces IN. Also, since you have to drive it in, the closed end would be out to give you something to drive against.....z

[zardiw]

PS. If your replacement seals are made by National, the printing will be OUT, and there will be little arrow/carets on the rubber part that point IN.........z

[Oldcarnut]

I don't know the brand and there isn't any printing on them. they are Carquest seals, same box as in your illustration. I thought the open side went in but psyched myself out and lost confidence. I went back and looked at the old ones and the one that was leaking was the one in backwards. The brakes are original so this has been this way since day one. The seal never leaked enough to go anywhere it could cause a problem. The inside walls of the drum were a mess though.

Thanks for the info.

John

[zardiw]

I know it's tough to determine which side on these particular seals because both sides look somewhat the same. Can you post some pictures??

Maybe use a magnifying glass to look at the insides closely. If you can see the spring that goes around, the spring side goes IN.........z

[zardiw]

OK, I took some pictures of my old seals. This is the side that goes IN:

http://www.lighthouse57.com/Pictures/Brakes/SealIN.jpg

The big highlighted circle shows the spring that is inside the seal. Also the small highlighted circle shows how the metal is formed when they make them. You can see the joint where it overlaps.

This is the side that is OUT.

http://www.lighthouse57.com/Pictures/Brakes/SealOUT.jpg

You can see a small secondary dust seal highlighted by the small circle. The large circle shows the printing 'National', and there's a part number somewhere there also. The metal shows no joint, and is solid.

Hope this helps................z

[Oldcarnut]

That is the way I put them in - thanks for the reassurance.

On another note, I read over your tutorial before I started this because it was so much easier to read compared to the shop manual. Last night something else stuck in my head. My truck has the 10 1/2" Chevy rear end so the retainer system is different. Mine uses one large nut with a woodruff type key for a lock instead of the bendable tabs with two nuts. However, you mentioned thrustwashers against the outer bearing. My shopmanual shows them but I don't have any. Up to this point everything has been fine. Do you or maybe anyone else know if GM did away with them at some point? My retainer nut is 1/2" thick and machined micely so it's a good fit to the outer bearing.

I'm the second owner of this truck and have had it for several years. The original owner told me the rear brakes were original. That doesn't mean someone didn't pull a wheel and check them at some point, though I doubt they would have pulled them both for a check. My common sense says if they worked this long don't worry about it. But now I've touched it and want it to stay together forever, any thoughts?

John

[zardiw]

That's a good question. But I don't have an answer :rolleyes:. If the manual shows them, I'd make sure they were there. Junkyard? Maybe call your local dealer and ask them......z

PS. You could ask your question here:

http://67-72chevytrucks.com/vboard/

z

[Oldcarnut]

I put the drums on and adjusted them loose and am going to bleed them. I will post on the other web site but otherswise will wait until tomorrow to put the axles in and see what the local dealer says. I just hope I can find them.

Thanks for the help and the quick responses and have a great day.

John