Author Topic: Wheel Cylinder Replacement?  (Read 11147 times)

Offline 313C10

  • Newbie
  • Posts: 19
Wheel Cylinder Replacement?
« on: November 12, 2010, 07:02:49 pm »
Just looking for some quick tips or past forums on how to replace a wheel cylinder.I have a 84 (custom deluxe) LWB 1/2 ton with in-line 6.Not sure what rear end its stock.
 Rear passenger tire keeps locking up when applying brakes and has been getting worse. Also letting off slower. It had been leaking a small amount for a while,and is also worse. I've only done brakes on semi-trucks/trailers, so any how-to's and what not to do would be greatly apprecited.
1984 Chevy Custom Deluxe I-6 LWB
1986 Chevy Blazer 350 TBI. 8?+ in. Lift

Offline topp

  • Frequent Member
  • **
  • Posts: 498
Re: Wheel Cylinder Replacement?
« Reply #1 on: November 12, 2010, 07:37:28 pm »
Spray PB Blaster on the bolts (2 of them) and the Hardline fitting into the MC for a few days PRIOR to doing anything....
'90 Suburban TBI 350

Offline 1979C20

  • Senior Member
  • ****
  • Posts: 1659
  • Kyle Taulton.
Re: Wheel Cylinder Replacement?
« Reply #2 on: November 18, 2010, 11:50:01 am »
I replaced both cylinders on my rear because I would fill the reservoir and the next day it would be empty, sitting in my DRIVEWAY! Make sure you have a good amount of brake cleaner, PB blaster on the 2 bolts next to the brake line and the brake line fitting itself at least 4 hours before. I have a full floater rear end, so I will tell you what I did and if you have a full floater then it will help you, if not, then maybe someone else can. I found it easier to jack up both rear tires with jack stands under the axle (but if you do one at a time you can keep your gear oil from leaking out too bad). Unbolt the wheel and set aside. Then, unbolt the 8 bolts on the hub of the floater and tap with a dead blow to break the seal loose. Slide the axle out of the axle housing and sit it aside, try to make sure no dirt gets on it. Grab a fairly large flat head screw driver and a dead blow. If you look inside of where the axle slid out, you will see a large hex nut with metal tabs keeping it from turning. Bend the taps out towards the outside of the axle housing so it will let the hex nut spin. If you have a socket big enough to turn the nut, use it. if not, place the tip of your flat head against one of the points on the hex nut and tap the screw driver with your dead blow to loosen the nut. unscrew the nut all he way and set it face down on a rag or something (so that when you go to put them back on, they are in order of what goes on first). If I remember correctly, there is another nut behind that one. remove that nut the same way. now, you should be able to remove your brake drum. Make sure the parking brake is released and pull the drum towards you. You may have to tap the back side of it with a dead blow or hammer to bump it loose. Once the drum is removed, I would take a picture of the brake show assembly for reference. Begin with pulling off the springs, starting with the one closest to the outside. On the brake shoes, you will see one round, slotted disk with a spring behind it and a pin through it to the back side of the plate on both shoes. with a pair of vise grips or channel locks, grab the outer edges of the disk, push it away from you, and spin it so the slot lines up with the wedge on the pin, releasing it. Remove the shoes, then pull the 2 pistons out of the sides of the brake cylinder. Remove the bolts from the back of the cylinder, and the brake line and then swap the cylinders. Reverse order everything and you should be set. Hope this helps!
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline 313C10

  • Newbie
  • Posts: 19
Re: Wheel Cylinder Replacement?
« Reply #3 on: May 12, 2011, 04:41:24 pm »
ok its been a while since i started this but, basicly i have the bed off my truck lowered it. i set the parking brake one day it wouldnt release i cut the cable and its still stuck a little bit im about to try to take off the hub off. that last post helped a lot im still confused if the brakes are on how do i get the hub off
1984 Chevy Custom Deluxe I-6 LWB
1986 Chevy Blazer 350 TBI. 8?+ in. Lift

Offline beastie_3

  • Senior Member
  • ****
  • Posts: 3170
  • Josh
    • My truck pics
Re: Wheel Cylinder Replacement?
« Reply #4 on: May 12, 2011, 04:59:40 pm »
I would wack the drum a couple times to see if the shoes release.

Offline Dr_Snooz

  • Junior Member
  • ***
  • Posts: 684
  • "I like to take hammers, and just break stuff"
Re: Wheel Cylinder Replacement?
« Reply #5 on: May 13, 2011, 12:05:33 am »
You don't have to remove the brake shoes to replace the wheel cylinder. Of course, what usually happens is that you open the brake up and see how bad the shoes are and that the drum is gouged and can't be turned and as long as you are doing everything else, you may as well replace the wheel bearings and seals... you end up taking everything apart anyway.

The way to get the drum off with the brake on is to back off the star adjuster wheel. If you haven't had the drum off before, then you'll have a hard time figuring out how to back it off. Basically, there is a teeny little sight window cut through the drum backing plate. The window gives access to the star wheel. Don't bother shining a flashlight in there, you won't be able to see anything. You use two very slender slotted screwdrivers. With one, you will push the ratcheting mechanism away from the star adjuster nut. With the other, you will turn the star adjuster. If that doesn't make sense, don't worry because it's even harder to do than it is to understand. I just bashed my first star adjuster until its ratcheting notches were rounded off. Once I got the drum off and saw how it worked, then the other side went easy. The star adjusters are available from the auto parts store and can be replaced pretty easily if you decide to bash it apart like I did mine.
1989 Chevy Suburban V-2500, 5.7L, TH400

1990 Chevy C-3500 Ext. Cab, 7.4L, 3L80

2009 Chevy Silverado 1500 WT 4WD, 4.8L, 4L60

Offline 313C10

  • Newbie
  • Posts: 19
Re: Wheel Cylinder Replacement?
« Reply #6 on: June 05, 2011, 05:45:10 pm »
i solved the problem with the parking brake by simply yanking on the cable but now about 3 weeks later my front l caliper is locked up
1984 Chevy Custom Deluxe I-6 LWB
1986 Chevy Blazer 350 TBI. 8?+ in. Lift