E-Brake Drum Out of Round?

[JackIIA]

Looking for abit of trouble shooting on my ebrake. I get some rub on the transmission brake drum regardless of adjuster setting. Since a picture is worth a thousand words, a video must be worth at least 2,000. That, and I wanted to take advantage of the cool movie embed feature (thanks Thompson!) and so have posted a quick video of the drum rub.

In the video, the first 2 clicks of the adjuster are from full lock of the brake drum. The second two clicks give a "no-rub" condition of the brake drum...until you apply the brake, release, and check. At that point, you get the rubbing back. It doesn't matter how far you back the adjuster out, the rubbing remains.

Does this suggest the drum is out of round, or somehow the expander isn't retracting. The expander was disassembled, cleaned, and greased up. The pistons do expand and contract when I pull the brake and put my fingers on the piston to check them. Movement of the expander assembly is minimal and the expander unit shaft feeding in to the anchor plate is fully releasing. Also, the adjuster unit is the NEW style which means you can't mix up the adjusting plungers.

Is some minor rub of the e-brake shoes normal? I would think no. Thanks.

_tIkJUM_dEs

[jac04]

I have always adjusted the e-brake so there was no rub at all.

Do you have the proper return spring mounted down near the bellcrank?

[scott]

Are your returny springies new? Are they installed correctly?

[SafeAirOne]

Is there a picture of (or a thousand words about) the handbrake with the drum removed?

[JackIIA]

Jeff - Yes. It's brand new. Getting it on was tough so I know it has some tension (not a ton though). And it hooks on the other end to the tx case mounting bolt.

Scott - Yes. New springs too. I believe correctly installed (per drawing in Green Bible).

[EDIT: Mark...here you go....]

I think I have the "early type" shoes on this e-brake. The manual says early type shoes are identifiable by half-round slots in the shoe webs. I'm attaching a pic of what I think that is. I suppose it's possible I actually have new style and am therefore installing the shoes incorrectly. But when I put them in the other way, they are not symetrical, but instead look like they'd constantly contact the drum. Plus, wear marks on the shoes suggest I've got them how they were before.

My only other thought is that these shoes are incorrect for the transmission brake. One source I talked to wondered if they might be shoes for the wheel drums, which I'm told have a greater curvature than the e-brake shoes. They came with the truck, so who knows. Here's acouple of pics.

[jac04]

Not sure it will help, but I would thoroughly clean the drum mounting surfaces on the output flange and on the drum itself. You want good metal-to-metal contact there in order for the drum to run true.

Edit:
You also appear to have the shoes installed incorrectly. Fully lined end of the lower shoe should be toward the expander. Fully lined end of the upper shoe toward the adjuster.

In your picture, both fully lined ends are toward the adjuster.

[JackIIA]

Edit:
You also appear to have the shoes installed incorrectly. Fully lined end of the lower shoe should be toward the expander. Fully lined end of the upper shoe toward the adjuster.

In your picture, both fully lined ends are toward the adjuster.


I wouldn't mind if the problem were that simple. I believe the shoes I have are the early type...in which case it's the slots in the shoes which determine orientation (and they should both face the adjuster). For the later type of shoes, the fully lined end of the lower shoe is fitted to the expander unit and the fully lined end of the upper shoe is fitted to the adjuster housing as you describe.

I could be wrong when I identified the shoe type, won't be able to look again until Sunday. Thanks for the suggestions.

[gudjeon]

I can't remember which one but the expander and/or adjuster is meant to be "floating". The nuts are locker type and not meant to be tightened right down to the backing plate. It could allow for some movement if the drum is not running perfectly true.

[jac04]

Also, do the old style shoes only go with the old style adjuster? Not sure, but something to look at.
The old style adjuster has plungers that come out at an angle according to the manual, similar to this:
http://3.bp.blogspot.com/_Tzy2hgZfA5E/Slyo7Z3PxDI/AAAAAAAAABI/UXVI1TinFxY/s1600/111_5565.JPG

[bmohan55]

this link to a UK forum may be useful, he talks about both old style & new style hand brakes...you may have to register to view it but there is a lot of good info on that board.

http://forum.landrovernet.com/showthread.php/71717-Replacing-the-handbrake-drum-rear-output-shaft-oil-seal.-Series-models.

[JackIIA]

thanks for the thoughts all. that website reference was a good one.

Jeff, you were correct. i had installed the shoes were incorrectly - they were NOT the old style. i misidentified based on the written description in the manual. i get pretty good spin now.

one last question on this....when I tighten down the brake output flange, I can't get it anywhere near the 85 ft/lbs required to make things work correctly. i chimed in on another similar post last week with this same issue. one thought for another owner was incorrect or missing shims for the speedo housing (which might bring the e-brake assembly closer to the tx box than correct). but my preload seems correct, and includes shims).

what i originally did was doubled up on the washers under the castlenut and tightened it down to the required torque. the result was a complete inability to turn the output shaft. what it appeared to be doing was pressing the rear side of the brake output flange solidly against the speedo housing and the seal, to the point of scraping off hylomar sealant around the seal.

so, i've gone back to basically how i found it originally, hand tight and cotterpinned (with two washers instead of one). there is no obvious play in the flange or lateral play with this arrangement.

so what is the downside of this approach. does it result in vibration at speed? will it shread the output seal? what is causing the disparity between the stated specs and mine. ideas welcomed. thanks.