Emergency brake (driveshaft) adjustment procedure

[The_Handier_Man1]

From: brians69d24  (Original Message)
Sent: 9/22/2006 9:56 AM

What is the proper procedure for adjusting the emergency brake that is driveshaft mounted?
There are 3 adjustment points that I can see; on the handle, the cable where it enters the backing plate, and the star adjuster wheel.

thanks
brian



From: denisondc
Sent: 9/22/2006 1:25 PM

Unless your handbrake cable is new and can be relied on to fully release, I would start by working the handle on and off a few times. Then check to see if the actuator arm inside the drum is being allowed to fully release. Dont worry if it doesnt drop back all the way - the bumping and motion of driving along will help it release the last little bit. But if the acuator arm wont move back by being pushed on, (such as if it needs to be hammered on with a screwdriver to go back all the way), then you might want to consider a new handbrake cable.
Here is how I set mine: I first adjusted the star wheel until I could hear some slight drag as the drum was turned. You have to operate the handbrake on-off in order to center the shoes, after you think the shoes are touching, since you might have to readjust the star wheel again. When the shoes touch the drum after having operated the handbrake, then the star wheel is probably set okay. I did this park before I reconnected the driveshaft, to make it easy to turn the drum.
Then adjustment on the handle beside the driver should be backed off, but still be 6 to 8 turns away from falling off of the mechanism. Lastly you adjust the nut on the cable, where it enters the brake backing plate, until it is just beginning to move the actuator arm.
I think you will find that after the first use or two you need to Turn the handle (tighten) a few turns to keep the RV from moving. I think this is normal seating of the moving parts. I have also found that I have to tighten the handle more if I plan to park on a steep slope. And maybe once a year, I back off the handle again, crawl underneath, and turn the star wheel a few teeth - like 4 to 6. I havent had to reline my shoes for the last dozen years, but then most of my driving/camping is in areas relatively flat and the parking brake doesnt get much use. I never try to stop the RV with that little 'parking brake'.



From: Coachmen1972
Sent: 9/24/2006 5:59 PM

If you get both rear wheels off the ground you can turn the drive shaft and hear what's going on inside the little drum.......

If the cable is not moving freely, take it off, and coil it up in the bottom of a five gallon bucket. Get a gallon of WD-40 or similar and soak it for a week....

Finally. I put a small barrel clamp (go to a bicycle shop) on the BACK side of the cable where it attaches to the handle......in other words not only is the cable held when you set the brake, it is also positively forced back in the outer cable when you release the parking brake.

My $0.03..

Oscar........trying to find the time to put the beautifully rebuilt Thermoquad with new Edelbrock cast aluminum RV intake manifold in Sir Gasalot, a 1972 22' Coachman, on an M300 chassis....



From: ClydesdaleKevin
Sent: 9/25/2006 7:20 AM

This is my 2 cents on the that little parking brake...lol:

First, that is exactly what it is...a parking brake.  It is not an emergency brake, and even with new shoes, and new cable, a new drum, and being perfectly adjusted, that brake will not stop your rig in an emergency...not a chance.  Probably wouldn't even slow it down.  Also, unless it is in perfect working order, it will not keep your rig from being driven!  More on that in a bit.

I took my cable off, hung it from a tree branch, and then sprayed the entire outer jacket, soaked it, in Tri-Flow...an incredible lubricant that has teflon in suspension.  The oil evaporates and leaves behind a teflon dry lube...good stuff, you can get it at bicycle shops.  Anyhow, I then sprayed Tri-Flow into the cable housing itself at the top where it was hanging.  I did this until it was finally dripping out the bottom of the cable housing.  I kept spraying it for about a week while I worked on other things.

I then reinstalled it, adjusted the star wheel in the little drum until there was just a faint whisper inside of contact, and then tested it.

Yeah, it keeps the rig still when you shift from park to drive.  It would probably keep the rig still on a SLIGHT hill.  But...if you step on the gas, the power of the engine and transmission WILL move the rig.  It will feel like you are stuck against a wheel wedge...and then all of a sudden break free and drive off like the brake wasn't even there.

The reason I went through the hassle of getting it to work was for Virginia inspection...but by the time I had to have the rig inspected, I had reregistered the rig in Florida, where there is no inspection...yay!

Anyhow, after all was said and done, I went back and adjusted the cable very loose...as loose as it would go, and then readjusted the star wheel so that the shoes have no contact with the drum.  Since I don't need it for inspection, and since I use wheel wedges to chock the rig when I park, I decided it was better to eliminate all possibilies of it dragging and reducing my gas mileage.

Kev



From: denisondc
Sent: 9/25/2006 7:55 AM

Before we start on a drive, as part of bleeding the brakes, I have my wife operate the parking brake handle repeatedly; while I lie underneath and watch to see if the cable really releases. Sometimes I have to nudge the actuator arm back (small hammer) to the -fully released- position a few times to have it behave as it should.
Then I try to remember to use it each time we stop - every rest area, restaurant parking lot, gas station, and campground. This way the mechanism gets some exercise, with periods of bouncing and vibrating in between - to allow it to fully release. I do this so it will continue operable. If you seldom or never use it, I think the mechanism will stiffen - so that when you do need to use it, the brake lining will be dragging (wearing out) afterword.

Kevin is correct: It is Only A Parking Brake - I think the manuals even call it that. I have found it will hold pretty well on a steeper slope....If I turn the handle clockwise several times before I engage it. I only do this on special occassions; so there will be less stress on the shifter cable, when taking it out of park on a steep slope. I really dont want the shifter/parking mechanism to get damaged!
After we are off the steep slope, I try to remember to unsrew the handle again so it will just hold the RV on a mild slope.