Another t27 parking brake query

[Soundout]

Hello all, and many thanks to those who have posted concerning electronic parking brake issues. I have recently ‘come over’ from VW to Toyota and was very impressed with my 09 Avensis until this problem arose. It’s a 2.2 diesel estate RJ09WOY.

After a rear caliper replacement, my EPB will not actuate while the engine is running, but will engage once the engine is off. It will not then disengage automatically but requires the button to be pulled to release it before moving off. The ‘check parking brake system’ message comes up. I am now fearful of engaging the parking brake in case it sticks in the on position and will not come off.

My mechanic has run diagnostics and is confirming that the EPB actuator needs replacing - he can clear the error message but the fault remains and the message keeps reappearing. Looks like a new actuator is required - woe is me indeed. 

For a car of this age, I am reluctant to pay the full cost of a new replacement. Used actuators are relatively plentiful on eBay, and they are listed usually as being good for all manual t27s from 2009 to present. But there are several model numbers for this part through the years. Does anyone know if different models are interchangeable? I can get hold of a very recent one but am wary that it will not work. Seems like the part changed in 2014 but appears to be identical otherwise? 

Any info will be most welcome folks.

Thanks in advance

Alistair Russell.

[Heidfirst]

1 hour ago, Soundout said:

I am now fearful of engaging the parking brake in case it sticks in the on position and will not come off.

Hi Alistair, welcome to TOC. ☺️

Fyi there is an emergency release in the boot.

 

P.s. the Passat (& other VAG models) of similar age apparently has a higher incidence of epb failure

[Konrad C]

The later EPB are not compatible as far as I am aware. From about 2012, the EPB had auto engage when the engine was shut off. My car which is 1.8 2009 model has the early auto release, manual engage. 
There is a post which I would need to find where somebody had an issue which their EPB, and it was caused by a faulty caliper. In your case the work was done but the EPB needs to be calibrated. Did the mechanic make sure both calipers work smoothly and evenly. Then there is the calibration process. You need the diagnostic software like Techstream or similar software or scanner (Have launch which can do this). 
Look at the following - 

Hope this helps.

[Soundout]

Thanks Heidfirst and Konrad C.

I’m aware of the emergency release handle but still have to think hard about where I apply the EPB so that I won’t inconvenience anyone while I go through the lengthy manual release process.

Good to know that there were two versions of the EPB. Clearly if I get a used unit, it will have to be the first version (manual apply, auto release). But that means it might be on the way out itself...hmmm. 

Please keep the info coming folks. The more I know the better.

[Soundout]

Thanks Heidfirst and Konrad C.

I’m aware of the emergency release handle but still have to think hard about where I apply the EPB so that I won’t inconvenience anyone while I go through the lengthy manual release process.

Good to know that there were two versions of the EPB. Clearly if I get a used unit, it will have to be the first version (manual apply, auto release). But that means it might be on the way out itself...hmmm. 

I appreciate the point that after the  caliper replacement, everything should be balanced and calibrated. The mechanic has the requisite software, but I understand that for this version of the parking brake, all that should be needed after caliper replacement is a long press of the button until it resets itself. The brakes worked perfectly for 3 days, including the parking brake, but then suddenly the error message popped up and the EPB started its odd behaviour. The brakes themselves are fine, no imbalance or dragging, freewheeling when required. Anyone else had this experience?

Please keep the info coming folks. The more I know the better.

[Soundout]

Update: yesterday evening, suddenly the error message disappeared and for 3 cycles of the EPB, it behaved properly (came on when activated with engine running, off automatically) but then it reverted to previous behaviour (only comes on when engine is off, needs manual release via the button, displays error message).

Any ideas? Konrad, I watched the video and will check whether the mechanic used the software to activate/deactivate when working on the vehicle. 

Thanks again all.

[Soundout]

Happy ending folks!

Thanks to advice gained from this forum, I realised that this could be as simple as a broken split pin attaching the cable to the rear brake assembly. That’s  what it was! Saved about £1000.

many thanks to all for information.

 

[Konrad C]

Great to know Alistair.

Was the split pin disturbed during the caliper replacement? Anyway it is always the small things that cause big problems. It always good to go over any work done, if things are not working as expected. I normally say this when someone says there is problem after a job, so will try remember to state that in future posts.  

🍾