Parking brake not quite holding after ‘sqealing’ fix

[revatron]

Hi all, after having the issue of the parking brake sticking/squealing or clunking when reversing after being disengaged I finally got round to getting the wheels off and looking at it.
It was pretty rusty in there so cleaned and lubed and freed everything up as best I could for a 80,000 mile car which has lived on a Scottish Island most of it’s life (sea salt and road salt etc).
The issue I’m having now is that the parking brake isn’t quite holding on steeper hills if I use the technique of tightening the adjuster until the parking brake bites, then loosening off 6ish ‘clicks’.
I’ve tried only backing off 4ish clicks to the same result.
The only way I can get it to hold is to engage the parking brake, tighten the adjuster with the parking brake engaged, release the parking brake then back off 2ish clicks.
When doing this the wheels will rotate by hand with the parking brake disengaged but with a bit of rubbing. This is obviously causing the economy to drop from over 4mi/kWh to around 3.3mi/kWh. Also the parking brake lever needs to be pushed to the floor around 11-12 clicks where before it was around 9.
Brake shoes/material were cleaned properly as was the disc so I’m pretty confident that this isn’t being caused by grease on the friction surfaces so I’m wondering if perhaps my shoes need replaced? I didn’t measure but I’d guess they have about 4 to 5mm-ish of material on them.
However, if the parking brake held before why isn’t it now? Because everything has been cleaned and lubed up?
2013 ZE0E EM57.
Any advice appreciated.

 

[nlspace]

if only there was a way for folks to share and indicate in their profile which model year they own...

There is a PB section of the FSM to cover the parking brake; probably have to look up the model year to see what it has to say.

Maybe the inner diameter of the brake drum has worn beyond the service limit?




p.s. Here is a fun video for the 2011 model, which has the electric motor driven version.

 

[revatron]

edited original to include, thanks for the input but could do without the snark. I’m human, I forgot to include it.

 

[nlspace]

Seems that there is 2 adjustments: one for the gap of the shoes to the drum, and another for the parking brake cable with respect to # of clicks at the foot pedal

If the first gap of the shoes to drum is too big, then i could see the parking brake acting up like you describe with either not enough or too much.

 

[revatron]

Definitely helped, thanks. Holding at 7 clicks now but economy still suffering a little. Can’t find the point where there isn’t rubbing but the parking brake doesn’t go to the floor.

 

[nlspace]

Probably have to repeat the procedure.
Release the PB and loosen the cable adjustment.
Adjust the shoes till locked then back off 7 clicks. Spin the hub to ensure no drag.
Then adjust the PB cable 500N (112 ft-lbs) tight at full pedal stroke.
Release pedal and make sure no drag,
then adjust for 190 N (44 ft-lbs) engagement of PB at 6 clicks of the pedal.
[i think a torque wrench on the wheel hub could be used to determine the engagement force]

 

[revatron]

Due to the age of the car is there a danger of stressing/breaking the cable? I’m worried repeated slackening/tightening may snap it.
The drop in driving economy may be due to short test drives around the neighbourhood - stop/start driving. Will give it a week and see if longer drives improves the economy (i.e more coasting, less stop-start etc).

 

[atikovi]

I’m worried repeated slackening/tightening may snap it.

If it snaps, it's too weak to begin with and needs to be replaced.

 

[GentleGiant]

I have had a fraying handbrake cable that was stopping the hand brake from fully disengaging, causing drag.

If you are still seeing MPG loss, it might be worth changing the cable (checking it involves pretty much the same as changing it).