Vectra C Parking brake imbalance

[Dog_Book]

Ok so the calipers are right assuming its a hatch, can only think of trying the handbrake adjustment again to let it go as far as possible. You'll have to push the rod back with force once the adjuster is lifted to work against the springs. When i fitted the replacement calipers on mine earlier this year it wasnt hard to slot the cable into the arm at all.

[Castiel]

First off thank you for staying patient with me. I realise this can be a bother and after 18 months of this issue I'm close to loosing it as well as finally fixing it.So thanks.

Ok so the calipers are right assuming its a hatch,

It is.

can only think of trying the handbrake adjustment again to let it go as far as possible.

My thinking too.

You'll have to push the rod back with force once the adjuster is lifted to work against the springs. When i fitted the replacement calipers on mine earlier this year it wasnt hard to slot the cable into the arm at all.

Bear with me here.

Last year I replaced the calipers after the cable replacement did not solve the imbalance. It did enough to pass the NCT then, but barely. When I did the cable I not do the auto adjust reset before installing the new cable. Didn't know about it so never done it. In essence I fitted a new cable to the "specs" of the old one.

When I done the calipers about 4 weeks ago I attached the O/S cable first and the N/S was an absolute pig to get on, but on it went.

Roll on the test and it failed on the imbalance on the O/S (the side I fitted first if that makes any difference) with it being 94% out of whack while the N/S was perfect. The results show the hold on the N/S was 2.250kN while the O's was 0.140kN so a 94% imbalance.

I took off the wheel when I got home, with the handbrake "Off", to find the cable had the handbrake essentially on, on the O/S while the N/S was in the "off" rest position.

Today, as outlined above and without rehashing it all again, I disconnected both sides from the cable, done the auto reset, reconnected both sides and while one went on easy (N/S done first) the other (O/S) was a bit tough to get on. However it took no where near the effort to get it on as it did 4 weeks ago when I done the calipers.

Now today with the handbrake in the down/off position both levers on the calipers are in the exact same position as each, neither one is more pulled than the other, and when I use the handbrake both calipers/levers are enagaging and then disengaging when I release the handbrake.

IOW the situation is improved both in a performance point of view and by simply looking at the calipers. The only down side is I have aslight drag/bind on both wheels (or it could be one, but a "spin" the wheel test showed both were stiff).

When I pushed the plunger/adjuster back I had my finger on the clasp to hold it and it took so much effort to get it back you know how fidly and stiff it is) I left it where it locked it. There was about 1.3 to 1.6 inches of the plunger still "out". This is when I done the reset.

If I were to push harder and have someone there ot engage the lcoking clasp of the adjuster I might get some more out of it and release that final bit. As you see in the pictures both levers on the calipers are only marginally away from full rest position. Before this the N/S was fully rested while the O/S was almost fully engaged (which I still find odd as there was no scoring, heating or excessive wear on the brakes and the foot test of the brakes came back with perfect results of 2.400kN on the N/S and 2.430 on the Offside. An imbalance of 1%.

Anyway my intention is simple.

Redo the reset and see if I gain anymore. Bleed the brakes once more for good mesure. Drive the car for a few days and see if they "bed in". As it stands now th car would fail on the binding (I assume) but performance wise its pass so as said above fixed one problem to cause another.

[Dog_Book]

Bleeding wont help, one test you could do is take the cable out of the calipers. Then pull on the lever to activate it and release then don't touch the lever. If with a wheel on or more noticeably without a wheel on it binds you know its the calipers new or not. Don't know what make you went with but i ended up going not so factory anal and got Remy ones which so far have been fine. If there is no binding you know its cable related, basically just too short. You've seen already the rod is under tension with that spring so always will be to a point as that's its auto adjusting part always pulling on the cable to keep it tight with a ratchet to engage and hold it.
After the above, you could always try the pump the brake pedal and hold it down which pumping the handbrake, hmmmm no thats for trying to make it auto adjust more to reduce travel. But if you do that anyway even before you pull it apart again you'll feel the handbrake feels differently as if its not pulling on anything. All worth a try to see if it helps. You just want those levers to return back to rest, assuming they are not the cause.

[Castiel]

Live update.

Car jacked up, wheels off, handbrake cable disconnected (took some effort again to remove one side while the other slips off once one side is released), and O/S caliper removed. As I work the lever on the caliper (for the handbrake) manually the piston comes out a little and stops, and the lever returns to full rest position when I let go of it. If I keep doing this the piston comes out a little each time and the lever back to full resting position.

Used a wind back tool to push the piston back in and tried the other side (N/S even though it wasn't flagged as the fault) and the same results. Piston out a little, lever to rest position when let go, etc, etc.

So that narrows down my problem to the handbrake cable. My only option now, as I see it, is to replace the original cable and see if the problem goes away. I only replaced the original cable as I mistakeningly thought it to be the problem last year, when in fact it was faulty calipers that were seized. So I'l replace the "new" cable (currently fitted) with the old one and see what happens.

More to follow when I'm done.

[Dog_Book]

So with the cables detached the pads were not binding on the discs?

[Castiel]

Sorry for the delay, meeting the guy to get the subframe done.

Yeah, spinning freely without the handbrake cable attached and no binding.

I can turn the disc by hand whereas before I disconnected the cable I could not turn the disc or even the wheel (while attached).

[Castiel]

Right I think I have the problem narrowed down, not solved though.

I have the "reset" done in that the plunger is still depressed. I haven't released it yet.

If I pull one side of the cable out as far as it'll go (doesn't matter which), then the other side retracts all the way in. So I clamped one side with the cable all the way out using a vice grip on the actual cable and not the armor. I then went to the opposite side and pulled the cable out. Took a bit of force but it came out. I then pinched it with another set of vice grips.

Pulled the handbrake lever and its tight and barely lifts.

The cable on both sides are still all the way out and if they remained that way then my problem would be sorted, but as soon as I remove one of the vice grips the cable retracts.

This sounds to me like the self ratcheting/adjusting mechancism is not allowing enough slack from the handbrake lever to the joint with the handbrake cable (circled in red below). As a result the sqaure metal part that fits under the heatshield/exhaust (again circled in Red) is "tilting" or "pivoting" rather than coming straight back and forth with equal pull. Its why I can get one side hooked onto the caliper with ease and the other takes a lot of force.

My thinking here is two fold:

1. Replace the handbrake lever with a "new" unit from a scrapyard then try the reset again.
2. Grab both cables (not armor, cables) with vicegrips and pull while the handbrake is in the reset position to "force" it to provide more slack.

Opinions, thoughts, etc.

[Dog_Book]

Is anything stuck or jammed on the connector?

[Castiel]

The connector? The bit from the rear of the plunger spring to the underside of the car? If so, not that I've seen. The "cable" pulls through ok and everything work as it should.

I'm going to be stripping the underside, including exhaust, in the next day or so to do the subframe so I'll have easier access then to check and verify.

[Dog_Book]

No updates?