Parking brake questions..( -89 SC )

J

Jogi

Registered User
(hand operated) Parking brake just not want to work very well. I have checked that parking brake lever (on caliber) rotates and there seems to be slight movement in brake piston when doing that. Those short left & right cables move freely too.
However main cable that comes from hand control lever seems to push out that thin cable protector plastic layer, it just comes out from end of the cable outer shell near brake adjustment "thingy" (near rear differential cover..)
I have been pumping the parking brake and stripping that plastic layer that seems to limit main cable movement when it grows to chunk at end of the cable.

So first thing is to replace parking brake main cable but I'm bit lost (again) which one is correct one in rockauto catalog... they list a lot of cables for -89 SC and lot of are surely not compatible, so if you kindly enlighten me :)


Any parking brake tips & tricks are welcome too :) ( In case that cable is not enough to fix things.. )
 
Oh well, I managed to get all loose plastic coating from the parking brake cable so I'm sure it is not that anymore doing harm.. Brake pads have lot of thickness left and I just installed new brake discs. Still parking brake does not brake much ie. I cant get rear tires to lock with parking brake even on wet tarmac or on "sand road".. :(
 
Oh well 2: Nothing else to try I disassembled a left brake.. I feel there is not much wearing in parking brake parts... there is little pit where that rod fits and it seems that piston really moves just a little.. 2-3mm (1/10"??)

What you think, does that part look like it should? (operating point of view.. )

I can't think anything else to check, mayby I just assemble it back together and try it again to see if it works better..
 

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I'm rather certain that the pitting isn't helping anything. You might try sanding+lubing the rod; or maybe just replace the caliper.
 
..yes that.. sealing might be bit problem in that area now as all "wonderful sealing dirt" is gone :) I'll try if I find something fill that area.
 
Well both rear calibers are now reassembled with new "repair" kits .. no leaks, all parts seem to works just fine except parking brake is still as weak as it was earlier. All for nothing.. :confused:

I'm really lost with this :(
 
Did you only replace the main hand control cable or just clean parts. Maybe the old rear cables have stretched and need replacing.

I recall someone saying that the later model (updated) adjusters, are the only ones available now and that they will work on earlier model cars

What did you do about the adjusters? Did you replace the rear cables with them, or just the primary cable? If you kept the old rear cables, is there any adjustment left?
 
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my ebrake is the same too

I've tried replacing the rotors, pads, piston seals, lubed cables to little gain. I can change both tires with the rear in the air and in neutral. But pull the brake while in drive and it walks away or does little; even turned the rotors blue in about 1/3 mile slowdown:mad:
 
KMT said:
Did you only replace the main hand control cable or just clean parts. Maybe the old rear cables have stretched and need replacing.

What did you do about the adjusters? Did you replace the rear cables with them, or just the primary cable? If you kept the old rear cables, is there any adjustment left?
Click to expand...

I just verified that all cables move freely. The adjuster is not working automaticly anymore (no tensioner spring..) but I did get it adjusted manually just fine, not too tight, not too loose. The hand brake lever moves little more than I could think it would do with fresh cables but there is still range left..
Cables are not stretched much, the adjuster still has about 3" reserve to tighten.. (about 1" or 3-4 slots used)
 
>The adjuster is not working automatically anymore (no tensioner spring..) but I did get it adjusted manually just fine, not too tight, not too loose.

I would repair/replace the adjuster.

Adjusting procedure in the book goes like this:
  • Trans in neutral w/parking brake fully released.
  • From under the vehicle, remove the retaining clip and pull the lever down (away from the threaded rod) to engage the tensioner. The tensioner will automatically remove the slack in the cable. Note: Do not pull excessively on the locking lever. The incorrect tension will stretch the cable.
  • Lock the tensioner by releasing the locking lever and check to make sure it is secure by rotating it toward the threaded rod.
 
KMT said:
>The adjuster is not working automatically anymore (no tensioner spring..) but I did get it adjusted manually just fine, not too tight, not too loose.

I would repair/replace the adjuster.

Adjusting procedure in the book goes like this:
  • Trans in neutral w/parking brake fully released.
  • From under the vehicle, remove the retaining clip and pull the lever down (away from the threaded rod) to engage the tensioner. The tensioner will automatically remove the slack in the cable. Note: Do not pull excessively on the locking lever. The incorrect tension will stretch the cable.
  • Lock the tensioner by releasing the locking lever and check to make sure it is secure by rotating it toward the threaded rod.
Click to expand...

That missing spring just removes the slack, really simple mechanish. I dont think that I did any worse job by manually adjusting the locking clip!?!?
If I tighten it 1 notch brakes could drag little bit, if 1 notch less, then hand lever travel would increase little and there would be little slack..

All I could think is to check really carefully how much lever on caliber really moves -> does it bottom? (which would be bad.. -> have to get new calibers)
If that is ok, then all there is left are the cables, some of them or all must then resist under force and not enough force is delivered to the caliber levers.. (cables moves freely when no tension is applied and under tension.. well it cannot be checked..)

Rpdboss: wellcome to the club :) let me know if you figure out how to get them working.
 
KMT said:
On your calipers....bleed screws on the top?
Click to expand...

Yes, on the top, I got them bleeded ok, and main brakes work fine.
The parking brake mechanish inside caliber makes me wonder that it seems to be very vurneble to any wear on threaded rod that goes into piston but when that happens, lever on caliber should then bottom..
 
How many km on the car/calipers?

Is there alot of road salt there?

Is this the customized SC I saw over there on the internet...?
 
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KMT said:
1) How many km on the car/calipers?

2) Is there alot of road salt there?

3)Is this the customized SC I saw over there on the internet...?
Click to expand...

1) Car: 290000km, calibers might be original, brake disks are new and pads are quite new too, about 10mm or even more material.

2) yes, enough to rust underside of the car :) Still parking cables looked quite good :)

3) customized...I think not, only some engine parts.. and I dont think there is much my car pictures on the internet, just few about front end accident while ago..
 
With that amount of kilometers on the car, I suppose it is possible the parking brake mechanisms at the calipers have simply worn out.

It seems you have checked and done all else you can with care.

Might be time to replace those items :)
 
Yep, new (remanufactured) calibers are not that expensive, but shipping costs makes cost to double.. and there is no point to use "core change", shipping cost are more than that.

Anyway, eventually replacing all items might be only solution..
 
My guess is that your cable is sticking somewhere. Common problem with older vehicles. If you can free it up with grease that would be great, but you may have to replace it. How far can you pull up on the parking brake handle before you feel tension? These parking brake handles can lift pretty much straight up when not adjjsted right.

One idea, is to take the cable off the calipers and pull the parking brake up and down to see what kind of movement that you have. There should be a decent amount of movement and it should move easily(at least an inch or so). If it doesn't move very far, your cable is overstretched and needs replaced. If the brake handle is hard to move, something is rusted and stuck in the cable and either needs greased if possible or replaced.

The adjustment mechanism should not hang down a whole lot.

Chris
 
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Update: So I could not get rear wheels to lock with parking brake and compared to all other cars I have had parking brake force was/is low... however I took the car to the inspection and it passed parking brake test!!!! :eek: (before I started this thread, parking brake test failed...)

So all this work was worthwhile afterall... :eek: and now I know SC brake calibers inside out :D
 
KMT said:
>The adjuster is not working automatically anymore (no tensioner spring..) but I did get it adjusted manually just fine, not too tight, not too loose.
I would repair/replace the adjuster.
Click to expand...
Ditto. My adjuster on my 5 speed slips with any real tension applied.. I'm thinking about swapping over one from one of my AOD cars as I never use the ebrake on either of them. That is until I can get a replacement adjuster. What happens it that lead/zinc type collar, the one that shaped like a "," wears down and won't grip the threads on the rod. I tried tapping it out and reinforcing the rod by winding wire around it, but alas... no joy. It must be replaced or remove the spring, cut the end off and "fix" it with 2 lock nuts :D.
 
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