Hand brake Adjustment

LarryC

Curator of #10105275
O.K., I have a new one. Done it many times. But now , no luck. It looks like I have moved into one of those new regimes where another method must be used for something that I have commonly done in the past and I am not finding the magical new method required..

Problem: Tightening the adjusting nut on the cable equalizer bar does not result in equal rear wheel locking. And it varies from side to side during attempts. And when I get one wheel (at least ) tight enough to do a respectable job of holding the vehicle, the hand brake handle is so tight that it is nearly impossible to disengage or only accepts about one click when pulled upwards. Usually one wheel is still relatively unlocked.

The lever at the calipers work fine when applied with a crow bar at the caliper. And very little pressure is required, so they are not stuck or balky.

If I try adjusting the tension by sliding the handbrake assembly forward, after loosening the lock nut an appropriate amount, I can get very little motion on the assembly. And in any case, the results are the same.

New cables, too.

Anyone else have experience with this scenario?
 

Black-Tooth

Tony Natoli
Strange problem Larry...

I can only assume you have this page and if the cables are NEW, then you've also probably been there, and done that!



If I study the drawing and understand what you wrote... I'm afraid I can only come to one or two or three conclusions, or possibly (most likely) all.

1. The "Swinging Arm", item 27 in this drawing, would be the only point where I could see such a "transference" of the problem as you describe. If ONE caliper, or ONE cable has even the slightest amount of MORE resistance than the other... then the transfer of pulling power or movement will be less on that caliper over the other one.

2. The possibility and probability of this occurring is highly LIKELY and is something that has always been there if we can assume every part is copacetic as you described. So in other words, its NORMAL and probably works just great in PRACTICE.

3. Yur nuts, and are either imagining all this stuff or screwing with us just to get attention... Again...

HTH...
 

mikemo90

True Classic
e brake

this might seem like a silly suggestion, but, but if you have someone to push on the brake pedal (in the air of course) do both wheels lock and hold tight? there is a helicoil worm screw in the center of the rear caliper that spins the piston when the parking brake is applied, hence the tab on the rear pad and the corresponding slot on the piston. might be that the worm screw has a nick, or the piston isn't rotating.
ya might attempt to pretend that you are installing a new set of rear pads and screw the pistons in all the way and see if the pistons move at all and see if you can pass the obstruction. might be time for a caliper overhaul, and the rear are a B##CH!!!
best o luck:headbang:
mikemo90*aol.com
 

ng_randolph

Bjorn H
The pistons don't rotate (except when you are manually screwing them in to make room for new pads). The only thing that rotates is a "nut" of sorts inside the piston (smoke blue in the image below):

Piston_assy.JPG


The gray plunger moves in and out of the caliper as you operate the hand brake. The purple plate, held by the gray clip ring, holds the "nut" in place inside the piston. Between the "nut" and the purple plate is a small ball bearing, allowing the "nut" to rotate. The red part is a spring tightly wound around the nut. What is not visible is that the bottom end of the spring is bent down and locks inside a blind hole in the piston, so the spring can not rotate. This spring is the "ratchet" for the self adjusting parking brake. When you step on the brakes, you are essentially trying to pull the "nut" off the plunger. Due to the coarse threads on the plunger (and inside the "nut"), this will cause the "nut" to turn. Rotation of the "nut" in this direction will tend to unwind the red spring, so the nut is able to turn in this direction. When you apply the parking brake you are forcing the plunger into the caliper, pushing on the piston. This should tend to force the "nut" to spin onto the plunger, but this would cause the red spring to be wound more tightly around the "nut", keeping it from rotating.

But to the actual point of your post: I agree it is a good idea to verify that both hydraulic brakes work evenly before trying to get the hand brake in adjustment. It is also worth stomping on the brakes multiple times to allow the self-adjusters to settle.
 
Last edited:

LarryC

Curator of #10105275
Thanks guys.. Those are all great suggestions.

I did the baseline test by checking that the pedal does in fact lock the rears, and it does.
ng_randolph, that is a great diagram and makes some sense of the otherwise mysterious internals of the handbrake operation at the caliper. I'm saving that in my "brakes folder".

The odd thing is that a manual test of the handbrake mechanism at the caliper says they are find. By manual I mean levering on one of the "swing arms" with a crow bar. This gets a very decided result on the wheel and locks it up right now. And with just a little pressure actually and miniscule motion of the arm, too. So that part works. What is strange is that the brake cable cannot effect the same results. Just the slightest pressure locks them up nicely. But the cable does not seem to apply the required pressure. Since they use to work just fine, I am leaning towards the possibility that the system is just worn and needs new calipers for a fresh start.

All of this is without mentioning the near impossibility of tightening the handbrake nut. It takes hours when all I can get is a bout 1/16 turn of the nut in that tight access opening before I have to swap to another wrench with a slightly different clocking and get another 1/16, etc. I need something like a ratcheting 13 mm box end wrench. Not to had locally unfortunately.

Yes, I seemed to have moved into a dark phase where things that use to work or make sense no longer do.
 

Dan Sarandrea (Phila)

Waitin' On Parts...
The thing that's new would be my "prime suspect."

Cables were replaced, so maybe the cables are pinched as they go around those confounded roller wheels that are "axled" by the two "Hey, what do these two bolts do?" bolts.
 

EricH

Eric Hamilton
Moderator
The thing that's new would be my "prime suspect."

Cables were replaced, so maybe the cables are pinched as they go around those confounded roller wheels that are "axled" by the two "Hey, what do these two bolts do?" bolts.

Dan, you beat me to it. I would bet long odds that that's the problem.

When I replace the cables (a hateful job that I put off as long as possible) I always take the tension off the old cables by slackening the bolts that hold the brake lever in place on the tunnel, slide the lever assembly backwards.

If it looks like I'll have to adjust the evil part 27, I do that while the cables are out and pull the entire rod 28 if necessary. The idea is just to get the adjustment to where the cables are slack with the lever assembly slid all the way back, taut with the lever assembly in mid position. That way I don't have to do a lot of turning of the unreachable locknuts on part 27 to get the final adjustment right.

A 13mm GearWrench or equivalent is absolutely essential for getting that nut adjusted.
 

LarryC

Curator of #10105275
Hmmm, you guys could be onto something

I suppose it would not take much for the cable to get off that pulley during reassembly. That could explain a few things. I will take look as best I can and see.
 

LarryC

Curator of #10105275
If that turns out to be the problem

I am not really clear on how I can fix it with minimum pain.
 

EricH

Eric Hamilton
Moderator
I am not really clear on how I can fix it with minimum pain.

- Loosen the bolts that hold the ebrake lever to the tunnel, slide it all the way back to get maximum slack.

- Unhook cables from rear calipers.

- Working underneath car, unbolt the plate that covers the pulleys, just aft of the tunnel. The hard part here is that the two big bolts are the shafts upon which the pulleys turn, so as they come out the pulleys will go astray. try not to pull the bolts all the way out, but because you're working from beneath it's hard to stop them from dropping free.

- Reinsert the bolts in the plate so that you can get the pulleys back in place and get the pulleys properly routed around the pulleys. Make sure that the fittings on the end of the cable sheaths are properly positioned.

- At this point, you will be thinking that the job would be easier if you could turn the entire car upside down so everything wouldn't fall out again when you tried to bolt the plate in place. You would be right, but unfortunately that's not an option. Instead, still working under the car, Use one hand on the head of each bolt to hold it in place as you lift the plate back into position. Use your third hand to start the bolts in their threaded holes in the chassis. No third hand? OK, you can use a piece of duct tape to hold the bolts kinda sorta in place so they won't drop out.

- Once the bolts are started, it's easy. Tighten them up, rehook the cables at the calipers while swearing creatively and copiously (this will come easily, as after the previous step you will be an expert at copious and creative swearing), reposition the e-brake lever and lock it down again.

This really isn't a hard job, but it is fiddly and frustrating and not much fun. If you have access to a lift and a helper, it's a lot less painful.
 

LarryC

Curator of #10105275
Thanks for the suggestions, Eric.

I will probably put this task off for a while as I do a few other things and come back to it after I work up the enthusiasm. I certainly miss being able to park on the small incline at the mailbox with the motor running. It was tough all summer with the condenser and radiator fans running and then shut down for 30 seconds and restart with both fan roaring away.
 

Red Bull 78

True Classic
Someone beat me to this "FIX", but I drilled a 1/2 in hole in the Cover so I can stick a 1/4 in Drive Extension thru it. Add a 13mm Deepwell and choose your weapon. 1/4 in Driver Handle, Power Screwdriver or Drill. Zzzziiiippp! Finish with a Ratchet Wrench. Stick a generic, 1/2" plug in the hole.
NOTE: Make it a 3/4 in hole, so you can just stick the Socket thru it. Too hard to Fidgit with the Socket & Extension thru the OEM Hole
 

Attachments

  • E Brake Cable.JPG
    E Brake Cable.JPG
    91.8 KB · Views: 90
Last edited:

Dr.Jeff

True Classic
I've never done the job of replacing or adjusting these cables, so I might be seeing things incorrectly. But for the two bolts that act as pivots for the wheels and mounting bolts for the cover plate, can you put a couple squares of card stock with "X"s cut in the middle over the bolt (on the top side of the plate) to hold them while positioning everything? I.e., the third hand.

Make a pair of these little squares:
1395046_p_060915.jpg


And place them here:
E Brake Cable.JPG


They should hold the bolts in place long enough to get things in position and tightened.
 

lookforjoe

True Classic
I didn't have an issue assembling the mechanism & then installing it with the cables. There is also an access plug below to tension the adjuster, albeit with a rachet wrench, not a socket.

X19_0345.jpg
 

LarryC

Curator of #10105275
Same here. I did not find the bolts to be an issue. I just used a little grease and they stayed put until completely re-installed. The handbrake ultimately :fixed itself" as I posted somewhere after that thread. Don' know why or how. But it works fine now. One thing that may have helped is putting a good washer between the adjusting nut and the cross-bar pivot rounded thing.The nut tends to chew up the rounded part and it get snaggy. No more snaggy. Now equilizes quite nicely.
 
Top