Parking brake no effect at all right side

Guys,
I´ve just rebuild all my braking system rear on my 94 BRM Wagon, due to German TÜV. There was almost no effect rear left side from the foot brake (hydraulic). Then I decided to make it perfect and replaced the shoes, wheel cylinders, all spring stuff and the parking brake cables. The front cable was ok, the rear right cable seemed a bit too short, but I could route it in order to clear some cm what was too short. The middle cable what includes the equalizer was wrong and didn´t fit to the Wagon, even the connector nipples were wrong. So i reused the old part ( just the middle one whats leads to the rear left wheel  incl. the equalizer) after checking it and it moved well. Then I reassembled all the brake, yet without brake bleeding and started to adjust the brake shoes and the parking brake (what is all independant from the hydraulic function).


Then I tested the parking brake and I noticed that the pedal travel is very long. Then I tried to turn the rear drums (wheels not yet fitted). The left hand drum was locked as it should be, but on right Hand I could turn the drum even with fully opeerated parking brake. So I thought that the nut at the equalizer has to be tightened  much more to bring clamping force to the right wheel. I tried it a couple of times, but the right wheel isn´t interested to move the parking brake not even just for a tiny amount, although the equalizer it tensioned like crazy.

The adjustment of the brake shoes is ok, I just can turn the drum by hand when the parking brake is loose on both sides.
Does anyone know this Problem? I`m not happy with this Equalizer, but I hope i can make it work, but I´m unsure what´s the reason why there is no effect at the right wheel at all. I even removed the drum and looked to the brake shoes whilst my wife operated the parking brake, no movement at all at the brake shoe. Please help me soon, I´m in hurry with the car, lots of thanks


Udo

Hi again,
I slept one night about this problem and found the reason once dreaming
I have located the counter support of the cable mantle not against the frame, rather against the equalizer itself where the pulling part of the cable is fitted as well. That was also the reason why the rear right cable seemed too short. So there was no relative movement between cable and its mantle, so no pulling at the brake shoe at all. It happened because the pre owner did it the same way wrong and in copied the same **** when replacing all parts. So looking back, there was probably never braking effect at the right wheel....the left one managed all parking brake by itself....

Thats my consideration yet in the appartment just whilst studying the manual what confirms this assumption. As soon as I´ve fixed it on the car, I will state it finally.

Ok, it was the reason as I stated before, now the cables are looking much nicer than before    The rear right parking brake works now basically, but it´s really difficult to get it equal on both sides. Apart from the basic problem before, could someone tell his experiences in getting the brakes equal? The RH parking brake is something worse than LH though I did the brake shoe adjustment as properly as possible. I Need a relativly long pedal travel to get the parking brake locked, if i tighten the nut at the equalizer even more, the RH wheel will be draged and I´m worried about to much friction and overheating
Could it  be that the brake shoes need some miles to break in and the parking brake effect will be much better afterwards? The drums are not new, but are looking ok so far. Not required to replace to my opinion.

I have not used my parking brake since I got the car except when I had to put the trans in neutral/low while working on the dash. I would rather put chocks behind the wheels instead of the parking brake. The only time you need it is for inspection (there are no inspections here). Putting the trans in park takes care of any possibilities of moving when parked with the exception above.

@Fred,
you lucky Americans have no TÜV to my Knowledge.....we have to do this mess every 2 years….
But if you don´t use your parking brake, it´s the best way to lose the function by not using it, in Germany called "Standschaden". I´m no sure if the parking position of the tranny will hold the car on a steep hill when being accidentially missused by locking it once the car is rolling yet. I think it´s just a hook what´s interlocking inside the gear what might damage something when missused - I think the parking brake takes load apart from the tranny components.
On a flat road surely no issue. Anyway, probably is there someone who struggles as well with the parking brake effect...

The trans has a pin that keeps the output shaft from turning. If you are parked on a hill, and your open rear is not broken it can not move. If you jack the rear corner on a hill with an open rear, it will rotate the lifted tire in the opposite direction that the car is moving. A limited slip will hold on moderate hills, but on a steep grade it may also allow a similar situation to develop, depending on which side you are jacking (left should not move, right may allow the car to move, 50 lb.ft. of torque on the limited slip clutch). This would be the only legitimate reason to have an emergency brake...changing tires on a hill. You could still chock the other tire, and be OK. Not using it can result in its malfunction, due to corrosion. For the most part the cable does not go through a sheath, and the sheaths are the primary parts that can cause issues. A good soaking with WD40 or equivalent would probably fix any binding in the sheaths.

Fred, thanks a lot and I would be glad if i wouldn´t need the parking brake as well as you….. Anyway, I hope there are other owners which maybe from Europe or even Germany who struggled as well with the parking brake in order to make it operate for the TÜV to tell me their experiences.

The basic problem is still that after the brake is adjusted and i operate the parking pedal, the right rear wheel doesn´t brake as good as the left one and -whats worse - if I release the parking pedal the right wheel doesn´t release completly from braking. I´m worried about the RH brake will get hot in consequence. I currently find no reason why the shoes doens´t release after releasing the pedal though the RH parking cable is brand new ( I´ve even checked that it´s working freely), all springs on the shoes are correctly installed, all contact points are lubricated but the shoes doesn´t release after loosening the parking pedal. I can´t hardly suggest that the drums could be the reason that the shoes doens´t release correctly. But right now it comes to my mind to swap the drums to each other to find out if there´s an influence…….


I´ve opened the rear brake now for three or four times and tried a couple of times to readjust the shoe spreaders (basic adjustment) as well as the equalizer nut to adjust the parking brake. I even disassembed the RH brake to lubricate all contact points. I checked if all springs of the shoes are correctly positioned. I´m pretty sure that if i tense the equalizer any more to decrease the pedal travel, the RH brake will work as it should, but it even doesn´t release the right wheel at all afterwards.


In the meantime I guess that the RH parking brake will never work as the left side physically due to the RH cable what is routed along the rear axle and there´s more friction inside than on the left side where it´s routed almost straight.  But anyway the brake has to work at least to be accepted by the TÜV and - apart from that -  the wheel has to be released completly after loosening the parking pedal.

In re-reading the entire post, there must be some problem in the cable for the right side. It could be binding in the sheath, the sheath may not be anchored properly at the ends, or the sheath may be internally damaged.

Does the cable pull out of the sheath properly at the adjuster when you apply the brake? Does the end of the cable at the adjuster pull the sheath into the socket, or does the socket/mount move when the brake is applied?

Hi Fred, thanks for your quick reply
I´ve even removed the cable from the frame fixing point ( near of the left trailing arm fix point) where the sheath is clamped, of course removed the cable bevore from the equalizer and clamped it off from all fixing points along the axle and the diff, then routed it straight behind the car and left the fixpoint at the right brake backing plate. All clamps are fixed perfectly inside the hole through the backing plate without clearence or any movement. I pulled the threaded end of the cable ( equalizer point) whilst looking to the parking brake lever of the brake shoe where it´s fixed. The lever moves, the cables moves freely, it´s brandnew. As long as the drum is removed, the shoes moves and releases. No idea why it doesn´t release when the drum is mounted. But I will double check it tomorrow again maybe with a mate to get it inspected more detailed with 4 eyes. Wifes patience will be stretched anyway... What I´ve noticed is that if the cable is fixed along the axle, the movement is a little bit worse than if it´s straightend behind the car due to the bendings, but that has to be accepted unfortunately, the spring loads has to overcome this…..

Me again, I also checked the cable completly with removing it from the bake lever, it moves perfectly, no binding at all. As well at the anchor points no movement of the sheath.

Yesterday evening I found out the reason for the problem. I removed the cable completly from the axle where it´s routed along with 5 or 6 bends up to the upper diff cover bolt. When it is straight pulled out of the anchor hole in the backplate of the RH brake, we could pull the cable without any Problems and move the shoe parking Lever as it should and it released perfectly. As soon as it´s repositioned back to the axle, the inner friction of the cable drags a lot and neither brake effect nor releasing is properly possible. I had a look to the Manual what routing is suggested by GM and it´s definitly no way to make it work with this routing. The cable is Dorman brand and I suppose that the inner plastic mantle of the cable is no real Teflon coating, maybe a minor suitable other plastic coating. As soon as it´s bent just a bit, you just feel more friction than as it´s straight.

I found an interim solution with routing it from the anchor point at the rear axle trailing arm LH underneath of the axle with a big bending underneath the tank leading directly straight to the anchor hole of the brake backing plate. So there´s one single big bending in one direction. As soon as it´s bent into the other direction as an S-shaped bend, there´s immedialtely big drag in side the cable, no chance to move it properly. Really disappointing and not easy to find out if there´s are obviously no installions faults. Probably I take the cable to an local specialist here in Germany and drop an order to amke a new low-friction one....

I am glad you found the problem. If necessary, a cable could be acquired from a local junk yard here, and sent to you, but it would be expensive to ship because of the size of the package. Dorman products are not always "exact" replacement parts. You should also contact Dorman, and they may even replace the cable.

How kind of you, Fred, lot thanks for this offer But as you can suggest, I would like to have a brand new part and because it´s that big package, it will be bent maybe other way than installed and after 5000 miles over the pond we are talking about the same problem probably

I also can hardly believe that Dorman makes another cable same size which is working properly and  shipping costs between USA and Germany are usually more expensive than the part itself at least with cheap ones. It´s annoying that obviously nobody has approved this parts and gives a feedback to the manufacturer. With these old parts, I guess that the original drawings won´t be ignored or not taken seriously in several details to keep costs down and as long as no one does complain, the parts will be dealt everywhere. Most customers might think that they have installed it faulty by themselves (as I did first by myself) and doesn´t have the guts to complain and find out poor manufacturing or whatever. But thats not still a problem in America, it´s just the same in Germany with reproduced parts of vintage cars…..

So it would very appreciated if everyone would tell about his experiences to make this stuff transparent, this would help to discipline the manufacturers to make better quality for the benefit of us all.

Final Statement:
The Interim solution with an new routing underneath the tank didn´t work as good as desired and there was not enough clamping force für the parking brake and it didn´t release steadily every time. So I had to investigate it once more and yesterday I found out, that the long spring inside the brake drum what forces the shoe to release is much weaker than the original one. The spring wire gauge is 1,25 mm at the Dorman part and the original spring is 1,75 mm (40% more !!!). Thank God I didn´t waste the original cable, it was not that bad, the cable was not like new but still acceptable and i replaced the new Dorman by the old one. Now the brake is working as new , as well the braking force is perfect and it releases perfectly even when I routed it the bent way along the axle ! Unfortunatly, I just noticed the difference in spring wire gauge not before I yesterday removed the brake shoe, normally you have not to redesign those spare parts. Anyway, the drag inside the aftermarket cable can´t be reduced as far so that the weak spring is able to make the releasing work, it has to be the stronger original spring in every case to release the brake. Tomorrow morning I have TÜV-date and we´ll see

It is amazing how a little part like that can cause so much trouble. Good luck with the inspection.

@Fred: Following your advice some posts before: Never waste good used ORIGINAL parking brake cables, however look to keep their conditions pretty good, much better that using nonproven junk parts

You are referring to junk "NEW" parts, I assume.

Yes Fred. Proven used parts are welcome