With the weather being so bad in the UK at the moment I have best avoided doing any maintenance tasks until it gets a little warmer. However a sight rear parking brake imbalance on the Vito was beginning to bug me, and the the day in question was sunny and dry although bitterly cold – I was going to have a quick look and adjust the shoes to balance the parking brake.
Its a simple enough task to drop the rear wheels off and click the adjusting spur wheel round a few notches through a wheel-bolt hole, bringing the shoes into contact with the drum – then back it off a noted number of clicks until the wheel rotates without binding, repeat on the opposite wheel and job done ! Simple….
As I dropped off the rear passenger wheel on the Vito (111 W639 2008) to make the shoe adjustment I noticed that there was a lip forming on the outer edge of the brake disc. As this is some thing that I usually like to remove when servicing the brakes myself, (dealer did it last time !) Thinking I would just drop off the disc and run around it with the grinder, I backed off the adjuster through one wheel-lug hole, removed the caliper completely by undoing the two 18mm securing bolts and then took out the single torx retaining bolt from the front face of the disc/drum. The assembly then pulled directly off the hub to reveal the parking brake mechanism/shoes.
Gulp! … Now being so glad that I had not just blindly adjusted the parking brake shoes to obtain best balance and just continued to drive the vehicle, I was met by a very unpleasant sight inside the drum that needed urgent attention – serious corrosion of the actual brake shoes and back plate. (These were genuine Mercedes shoes, with stamped logo and OEM part no.6394200220 ) Honestly never seeing anything quite like this ‘rotting’ of the shoes in my many years of mechanics, additionally so on such a modern vehicle with a documented service history (2008) was to say the least, a tad disturbing.
A quick phone round to source replacement shoes was a total waste of time as it was Easter Sunday and the places that were open had no stock – So I decided to strip both sides and do a ‘proper job’ in readiness for the new shoes ordered online to be fitted in the next day or two.
All the time I was working on the vehicle cleaning up the parts that were in very poor condition, I reflected how fortunate I was to have made the decision to remove the disc/drums to take a look inside. This was further underlined when the friction lining totally de-laminated from the steel shoe support on its removal. What a mess !
Having stripped the back plates and cleaned them up with a wire brush and in places used a Dremel grinder, paying special attention to the raised surfaces where the shoes slide during actuation, as any rust here would for sure hinder their smooth sprung return when in use.
Cleaning the inside of the drum revealed little wear and only the slightest lip to be removed with a file so that refitting and future removal would be made a lot easier without snagging the shoes as it slides off the hub. Lips were removed from the outer and inner edges of the disc area with careful use of a grinder and finishing with a file, they were then treated to the same paint coating as the back plates – all awaiting fitment of the new parts. New parking brake shoes were purchased from here, super quality German manufacture and fast delivery – above all excellent value. I also bought a set of new DELPHI springs and retainers from here, again fantastic value and truly fast delivery. The job was done for less than £35.00 !! MB want over £100.00 for the shoes alone, seeing how the original OEM parts had deteriorated I have little problem in using parts sourced from an alternative manufacturer.
My advice to anyone contemplating blindly adjusting the Mercedes Vito parking brake is DONT ! Unless you can personally vouch for the condition of what lies inside, I recommend having at least a look inside first, just to see what condition it is all in.
Better to be safe than sorry!
20 thoughts on “Mercedes Vito W639 Parking Brake – WARNING! – Don’t adjust the shoes without INSPECTING THEM FIRST !!”
Got to the point where I need to back off the adjuster to remove the disc, and it appears that the adjuster cogs have corroded off. This is the off side and at the 11 o’clock position. Can’t believe it! Getting desperate, just want to yank the whole thing off. I know I need to order new brake assembly anyway.
Has anyone got a suggestion?
If you are sure there is no star wheel left to rotate, (take a pen torch and have a careful look through a wheel stud hole to be sure you are in the correct position) Then the best thing to do is grind or twist the hook off the two shoe retaining spring pins at the back of the back-plate so they flirt inside releasing their spring tension, this should allow the drum assembly to be removed with a bit of wiggling – as now the shoes are no longer retained to the backplate with the hold down springs giving some angular play to the shoes to get the drum off. (use of a Dremmel is best for this if you have one)
You should really use a new spring kit when you rebuild the assembly, so damaging the old ones at this point in the proceedings will not matter. Make sure you grind the ‘wear lip’ off the inside of the drum before you refit the new shoes, as this is what is preventing you getting the drums off now.
Hope this helps, Steve
I have new discs and pads and was planning to get on with that until I got to the point I stated previously.
I have reassembled for the time being as I’m certain I will need to obtain shoes, springs and new adjuster. May as well do a total refurbishment as I suspect there’s bad corrosion.
Thanks for the tip for disc removal, I was getting frustrated.
I’ll post how I get on, though it will be next week now.
+1 on the fitting of new springs. I recently had to change the shoes on m 639 and did it in a huryy so didn’t have new springs (Sunday afternoon job). Within a few day I was stripping them down agin to remove the bits of broken spring to fit new ones. Luckily I was not too far from home but the noise was horrendous.
Thanks for the additional info,
I`m glad I stumbled across this site, this prompted me to examine the rear brakes on my 111Cdi & OMG…….. I will be following your detailed process, but the one item that has sprung to mind is HOW did you clean up the dust covers ? were they done in situ or did you remove them. If it was the latter, I take it the bearing has to be removed to access the bolts that hold the dust cover on.
Once the shoes and springs are all removed from the back plate (dust cover as you say) it is quite easy to give them a good going-over with a rotary wire brush on an electric drill. This will remove any rust and scale readying them for painting with a liberal covering of something like Hammerite or other rust preventing paint. Once it has fully dried, clean off the ‘raised’ areas where the shoes ride and pivot points (this can be done with a sharp knife or old woodworking chisel) these will ultimately be smeared with a thin coating of copper grease to assist the shoes travel on the back plate as they are applied and released.
Hope that helps.
All the best
Thanks for your prompt reply.
Many thanks for taking the trouble to post this up Steve – very useful indeed. My own W639 109CDi has just had the same issues involving delamination of parking brake linings. I wanted some comfort following my local repair garage telling me it’ll require new disks, shoes etc. and I can see this is a common issue so I’ve let them get on with it. Best wishes.
Thanks for the kind note Tony,
The linings get pretty bad in there don’t they, and I do wonder why. I think what happens along the way is they are maybe over adjusted at service or do not fully release from the drums (due to some back plate corrosion) and so they drag ever-so-slightly on the drums. This heat over time bakes the linings and burns off the protective lacquer/paint from the shoe’s steelwork allowing moisture and condensation to do its worst in this unseen environment. That is about the best reasoning I can think of, because all the ones I have seen look like they have been standing axle deep in water for a year or two !
All the best
I had all the above issues, i found fitting the retaining springs on the replacement handbrake shoes,i ended up compressing the springs using 2 small cable tyraps, this made fitting them easy. then cutting them after the springs were rotated.
Thank you very much for your info !
Really really helpful !!!!!!
Help! todays plan was to replace all front and rear discs pads and handbrake shoes as pads were low and hadbrake not working. on removing the rear discs/drums i found all the shoes and springs loose in the drum. from what i can work out the shoe retaining springs go through the backplate through a slot that has long since rusted away to a large hole. it seems autopart places cant supply backplates so presume its a mortgage with Mb dealer and do the hubs have to be removed for replacement. thanks in advance for any advice. richard.
It’s quite involved to remove the backplate. You could use a repair washer, large diameter with small central hole to thread the holdback spring hook through on the rear. It will be a fiddle and probably need two people to orchestrate, one fully pushing in the spring from the shoe side while the other hooks the washer over the protruding hook end of the hold back spring. Careful selection of washers that fits the bill will be the key here.
Hope this helps
Great article and very useful assisting me to service my rear brakes on 2009 Vito 111cdi. Mine were also badly corroded. I changed the brake back plates £15 each from mercedes Newcastle on eBay which meant removing the hubs. Took an hour each side to get each one off with a hub pulling slide hammer but worth the effort. The hub nut is a hefty 41mm and requires some herculean strength to loosen.Parking brakes proved a pain to re-fit particularly the springs to the back plate have now invested in the proper fitting tool from eBay. The pads also proved a challenge and well worth renewing the retaiing clips holding pads to caliper. Set aside some time to complete the work mine has taken up weekends already but saves on a garage.
Thanks for the comments Rob,
Glad it helped out.
Hi Rob, you mentioned a special tool to refit the springs what is that? I’m about to overhaul my rear brakes on a 2012 122 639.
I have purchased springs, shoes and discs. The pads have quite a bit of life left.
You can simply use long nosed pliers or if you are ‘super-keen’ you could make one of these from a redundant flat blade screwdriver.
All the best
I’m just about to overhaul the rear brakes on my Vito and this is a really useful thread. Many thanks to all the contributors.
Put new backing plates on my W638 bus, had to cut out a section to get over the hub but it didn’t compromise the 3 securing bolt holes and it all sits correct.
Had a nightmare putting the new discs over the new handbrake shoes despite everything being backed right off.
Going to try and fit 1 old shoe and 1 new shoe and hope that gives me enough play to fit the disc on.
Everything has been renewed by the way, thanks for the article and tips.