Recently the Mercedes has been behaving itself quite well,  however this all ended recently when a new issue developed on Sunday, releasing the parking brake the release lever jammed sort of halfway out and the foot pedal would ratchet down, but not stay down. So the parking brake basically wouldn't stay on. 

My car has a ludicrous foot pedal parking brake with an organ-stop release lever. The pedal is to the left of the clutch, and the release lever is above your right thigh sitting in the drivers seat. In an auto, its sort-of-ok but in a manual like mine, its just a terrible idea. Hill starts really require three legs to do effectively. 

Anyway, the two parts are connected with a bowden cable that goes over the top of the steering column. pulling the release uncouples the ratchet mechanism pawls and the pedal springs up, retracting the shoes on the inner edge of the top-hat bit of the rear discs. Its enormously over-engineered and after 22 years, its a bit flaky. This is slightly compounded by the car occasionally jumping out of gear, so I could park it and leave it in gear, but I wasn't 100% sure it wouldn't jump out of gear while I was away then roll off and crash into another car, or worse - hit a person.

I tried at the release end first, reasoning that the cable may have come detached from the release handle. This was sort-of right, it had, but there was no tension on the cable at all. the release handle is in 2 parts, and I managed to break the 'wings' off the bit that secures the outer bowden cable sheath to the inside of the dashboard. Off to a flying start then.

a bit of Google-fu suggested that this happens from time to time and often its part of the pedal assembly that falls out of another bit and stops it all working correctly, so I set to trying to see if thats what had gone wrong. if it wasn't that, then £100 of 2nd hand parts and a lesson in contortion was going to be in order, so I crossed my fingers!

To get at all this stuff, you need to be headfirst in the drivers footwell, so step one was removing the drivers seat to get space to lie on my back on the floor

The seat is held down with 4x e-torx screws, then you have to disconnect the electric seat motor cables and lift it out. These seats are pretty heavy, and I'm a weakling. Eventually it was out though

This is the view, access is mostly obscured by a kick-plate directly above the pedals

Then undo 3x torx head screws and then bend the plastic kick-plate out the way to get at the parking brake arrangement. Pressing the pedal pulls the cable (which runs down the transmission tunnel to the rear brakes) taught and its just a massive answer to a question no-one was asking.

Giant stroke of luck here. The yellow-circled bent bit of metal had indeed just come adrift from the lever it ought to act upon, this should locate into the hole in the black thing - marked with a blue arrow. This was literally the best possible outcome. I grabbed it with a pipe wrench and manhandled it back into where it ought to sit

Much better! It was fiddly but eventually located and I was able to press the parking brake pedal down, it ratchets and locks - it wasn't popping back up again. Excellent stuff. Its a very complex arrangement for a basic function and a combination of the location and obstruction of the lower dash and carpet meant I couldn't really see the full workings, but it seems happier. I reached up and pulled the end of the release cable wire (hanging out of a hole in the dash because I broke half the release mechanism) and to my relief the pedal sprang back up - so we're 80% working again. it will ratchet down and lock, and will release by holding the bowden cable with one hand, and gripping the sheath with the other and pulling it.

While the seat was out, I took the opportunity to hoover up all the crap that accumulates down the side of the seat and under the runners

I then refitted the kickplate, seat and wiring stuff. I now have a functioning parking brake again, a sore shoulder and a great sense of satisfaction of a job well done.

I ordered a replacement for the thing I broke as it won't take long but is a bit fiddly to access. I gingerly applied the parking brake to full travel and was massively relieved when tugging the cable end hanging out the dash got it to release correctly. Obviously having a bit of wire hanging out the dashboard to release the parking brake wasn't exactly ideal...

The old one, with snapped off ears is on the left, the new one in the centre, and the bit you hold on the right. Step one was chocking the car and releasing the handbrake, the popping the side of the dashboard off to expose one of the fuseboxen

I undid the retaining screw and pushed it down out of the way to allow access to the inner dashboard. First step was to wiggle the new inner release handle thing into place and screw it into position with 2 flanged torx screws through the lower dashboard

You can see I then pilled the bowden cable through the slotted bit of the release handle mech. This is where it got fiddly. The next bit you have to pull on the cable to pull through as much slack as possible, then slide the release handle into the inner bit, pop the 'bobbled' end into a recess in the release handle, then wiggle the bowden cable into a Z-shaped slot to stop it popping out while in use. To do this, you need toddler hands and a fearsome grip to keep it all in position while you wiggle a tight inner bowden cable into the channel. All accessed through the side of the dashboard. After a bit of swearing and some needle-nose pliers and a small screwdriver were used, it all popped into place

Which is kinda visible here, if you know what you're looking for? At this stage I tried depressing the foot pedal and was slightly* vexed to find it popped back up immediately, so the release cable was too tight, even with the release handle all the way in. I then wiggled the outer bowden cable sheath a bit* and there was a clonk as the sheath slid further down the cable and then it worked fine. I think the  sheath had ridden up too far, and just needed re-seating at the pedal end. With this done, the foot pedal stayed depressed and popped up correctly when the release handle was pulled. I squirted a little bit of chain oil into the 1" or so of cable and worked it in and out of the sheath a bit for good measure. Then refitted the fuse panel and closed the side panel.

It all works correctly now, hopefully for a while. 

I put a for sale ad up for the Merc in a bit of a toddler tantrum, but having looked around there is absolutely nothing I'd actually want to buy under £10k, there were a few Saab 9-5's with the 2.3t engine which looked tasty, but they're in the £700/year tax bracket and are 16 years old. They're for sale at £3500 or so, and I just can't justify spending that much on a only-slightly-newer car, with double the tax. Its a bit grim, but I'm just better off using the money to keep this car going for another year or two. It has its foibles, but by and large its cheap and relatively easy to repair, and the things that aren't either cheap or easy (replace gearbox to try and fix issues selecting reverse) can be lived with/worked around in the meantime. 

Next on the list though is probably to have a serious look at the cam magnet thing which is leaking oil down the leading face of the engine block. Incidentally, changing to 10w40 has entirely silenced the startup noise from the cam chain so thats a result.