Apparently common for these to be over-tightened on assembly, stressing the plastic resulting in cracks.
The actual fastening torque is very low, only 11Nm -screwdriver type stuff, not socket-set stuff!
Also but perhaps less possible that over-zealous use of threadlocking compounds can weaken plastic and rubber materials.
Not ruling out crappy Asian-sourced OEM parts, of course! “If it ain’t broke, don’t fix it” -where’s the fun in that?

Well I've just had my third parking break actuator fail (that said I'm on over 190,000 miles so not too bad I suppose). Luckily happened at home and I managed an easy DIY fix as follows:

- Put the car in the highest suspension height and support with an axle stand

- Lying under the car remove the actuator bolts and lift it off the brake caliper - access is quite easy

- Unwind the brake manually (there is a section showing how to do this in the workshop manual - basically just turn the spindle clockwise)

- Put the actuator back and put a piece of tape over the handbrake switch so that you don't inadvertently apply it and lock the brake up again - I find that when they fail it tends to be intermittent at first so better not to keep using

- Order new actuator and swap over with the faulty one - easier to take the wheel off for this but possible without - (when my actuator failed my car was in the garage too close to the wall for easy wheel removal). Make sure you torque to just 11Nm - I also used some loctite.

The main thing to note is that you can release a locked brake manually in 10 mins provided you have some basic tools then you are mobile again (albeit without a parking brake) so no need for recovery trucks or replacement cars whilst you wait for the new part to arrive/be fitted.

^^^ I did exactly this a while back.

I ended up taking a punt on an aftermarket part from eBay and it's been fine ever since.

Bargain at £16...
https://www.ebay.co.uk/itm/314479516987 Kev

2014 L405 RR Vogue SE 4.4 SDV8 in Corris Grey
2010 L320 RRS HSE 3.0 TDV6 in Stornoway Grey

I'm a bit late to the party on this one.

However, when replacing my rear brake shoes & discs, I noticed that the parking brake motor housings were cracked. I realised that would allow water inside, which I didn't want.

I also realised why they crack, and as such why just fitting a new one is not a long term fix.

The problem is that the aluminium caliper boss corrodes and expands. This expansion bursts the motor housing.

So you have to clean it up with a file, including in the o-ring groove.

On reassembly I have it all a liberal coating of copper grease to try to prevent the corrosion in the future.

Time will tell.

Chris.

P.S. The cheapest I found the motors was about £22 ! L405 - 4.4SDV8 Vogue
P38 - 4.6V8 HSE
Land Rover series IIA V8

Chris, I don’t think you should have used copper grease? It’s mineral based and may denature the rubber O-ring seal:

https://www.autotorque.news/the-aftermarke...er-grease/

There’s a special red brake grease silicone based, you should use liberally inside these, but I can’t remember what it’s called, -perhaps Phoenix or someone can advise?l “If it ain’t broke, don’t fix it” -where’s the fun in that?

Last edited by Gremlin500 on 7th Oct 2023 3:51pm. Edited 1 time in total

Ditto, use Loctite sparingly and keep off rubber & plastic parts, it WILL make a mess of rubber in short order. “If it ain’t broke, don’t fix it” -where’s the fun in that?

Copper grease is the worst possible to use - you're just adding another metal into the mix...
Red rubber grease could be used - but there's not much point as it's intended for seals that move (behind hydraulic seals etc.) Clear silicone or white (Zinc oxide) grease is ideal as they have high viscosity and a high dielectric strength to prevent galvanic corrosion as well as being less likely to be washed out by surface water and allowing the aluminium to continue oxidising.
C Bennis Supplies on fleabay do some handy small tins (and big tubs!) of modern & specialist greases, although standard LMP grease would do a better job than copperslip - which should be kept well away from vehicles IMO.

All very useful to know!  “If it ain’t broke, don’t fix it” -where’s the fun in that?

Has anyone had a resolution to the issue when a new actuator didn’t fix the issue?

I had a fault code for the left parking brake motor. So took the wheel off and had a look, the motor was cracked in two places. So I bought a new genuine one and fitted it. I’m still getting a fault code for left motor short to ground. Car has been in at a local auto electrician and they can’t find any shorts in the harnes, they’ve checked all the connectors. They couldn’t get the fault to trigger. He said it could be the module but I’ve seen others on this thread who said that hasn’t fixed the issues either. I’ve literally drove the car 15 miles home and it pinged up just as I was about for park outside my house.

Seems to be when I’ve driven through a lot of standing water it happens. It was present for 3 or 4 days last week when it was really wet. Happened the other day in the slushy snow and like I said, again today after driving through 4 patches of standing water. I’m sure there is a short somewhere that only manifests when there is water ingress to the harness.

Well I had a twist to the usual problem. Fitted a new brake actuator only for it to fail within a month or so (or so I thought). The replacement didn't work either and on investigation I found that the splined shaft in the caliper had worn to the extent that the actuator was able to spin without moving the brake. A replacement caliper fixed this. At least I have a spare actuator "in stock" now.