Outer Sill Replacement - removal

I find myself carrying out a repair I hadn't expected to do - but I suspect that is naive of me as the outer sill as notorious rust traps - but most DS owners remain blissfuly unaware of the corrosion hidden away behind the sill trims until it is very advanced.

Replacing the outer sills

When I was starting work on the car, back at the farm in 2014, it became clear that at least one of the front jacking points was corroded and would need some kind of repair.

Rot in the right hand jacking point. 

You can read about that repair HERE. 

It was barely visible but under all the road dirt and grime, but at some point in the cars past, someone had tried to jack the front of the car up from the outer sill on the left hand side and had damaged the sill cover.

Hard to spot: telltale damage to the sill cover

I guess this was either before my ownership or when I owned it but it was sitting abandoned at the farm. The car had been moved around several times then by 'non-DS' people, finally ending up tucked away in a corner.

Fast forward to December 2019 and I was beginning the work to replace both jacking points. Over the Christmas break I removed the carpet and trim from the sills to give me better access to the base of the 'A' posts.

I started by removing the dented lower stainless cover from under the sills. This was dirty and the screw heads were rusted in. 

The screws holding the spring mechanism for the rear door had to be removed. The main bracket straddles the 'B' post and is held in place by two large dome-headed screws on either side, released from the outside of the sill. 

Retaining screws for rear door spring mechanism

On the top of the sills, pulling back the Pallas carpet revealed a row of screws holding the carpet finishing trim to the sill top surface. The sill trim was held down by this.

Screws are hidden under the carpet edge

In some places the edge strip was simply holding the main sill trim down, but there were a couple of screws. Again, the screws were rusted in and the heads corroded. particularly in the corners by the rear seat.

Rusted screw head

In most cases I needed to resort to an angle grinder to remove them. Access was limited and some collateral damage to the stainless trim was inevitable.

Angle grinder damage

The vertical edge of the top trim sits in a groove above the bottom white, rubber, door seal. Removing that strip......

Screws are hidden under the top trim piece

....gave me access the the stainless steel trim on the vertical face.

Removing the finishing strip helps to release the vertical face trim

Removal of the outer trim revealed the extent of the jacking damage. Luckily it was just a crumpled outer sill. 

Crumpled outer sill

Thankfully the outer sill is non-structural as there is an inner box section that gives the chassis it's main strength. The outer sections provide convenient 'ducts' for channeling pipes, cables and rods between the front and back of the car.

Construction of the sill. Left side from rear door forward

Removal of the trim also revealed the almost inevitable corrosion along the underside of the outer sills where the trim fixing screws had been. That rust undoubtedly weakened the outer sill too. This rust is pretty typical for a DS.

Typical rust areas in DS sills

The rust here probably weakened the sill and so further reduced the likelihood of it bearing the weight of the car when it was being jacked. 

In my case I judged that just about the whole bottom edge - most of the length of the car on both sides  - would need to be patched with long, thing strips wellded-in. 

Just about the whole bottom edge was rotten

That represented a lot of welding as far as I was concerned. And there was  also a high risk of warping and distortion. And I would need to do it lying on my back. I decided, like others before me, that it would be simpler  - and provide a longer term fix - to totally replace the outer sills. It's not a decision I made lightly as I want to keep as much of the original car as I can. However these pieces were on their way out, were tucked away out of sight and, as the outer sills are not structural, I decided to replace them. The replacement parts were ordered up.

A box of goodies: 31 March 2020

When the cars were first built the outer sill panels were one piece and ran from beneath the 'A' post to beneath the 'C' post with the 'B' post sitting on top, half way along.

The outer sill is the bottom horizontal edge of the top piece...

The original outer sill was a single piece per side
(Photo copyright Jint Nijman)

Most repairs/ replacements will only be to the  between the door posts. So the replacement panels are sold in two parts and need to be cut to length - depending on how much is being replaced.

Replacement outer sill panels: two per side

By mid May I had cut out the old sills - starting with the left side of the car. 

Working from under the car I completed removal of the rear for spring mechanism by removing various circlips and springs to release the rollers and arms.

Bracket for rear door spring mechanism

It was then a case of winkling out the bracket from the 'B' post.

Removing the spring mechanism

Removing the sill was then a case of drilling out the spot welds along the top surface and  cutting through the vertical faces of the rotten sills at the appropriate points.

Drilling out the spot welds

In both cases, and on both sides of the car I was very carefully to avoid cutting or damaging the various pipes and cables hidden within the outer sills. I was able to get a good cut line on the back end of the left sill, but still needed to cut out the remains of the channel for the door rubber as it had rotted away.

Removing the channel that holds the door rubber

I think capiliary action must draw water up inside the channel. Don't let anyone ever tell you they have a 100% 'rust-free car'......

Notice the pipes and cables within the sill - careful!

The front end of the back section was more difficult. In the photo below you can see that the large aperture in the sill piece is very close the base of the 'B' post - where the channel that holds the rubber door seal is located. 

The edge of the aperture is close to the vertical seam

That would be awkward to weld. As with the back end, the door rubber channel was already rusted, so I removed the bottom section to give me a better cut point on the sill further from the aperture. That was quite destructive......... 

Looks a mess but is easily repaired

.......but gave me a little more welding room to work with.

Sizing up the replacement panels

I applied the learning from tackling the back section to similarly removing the front section of outer sill.

Cut line on the front half of the sill

Remember this grainy photo of the door spring retaining screws? 

When replacing panels,  keep this distance between the screw holes the same!

One very important consideration when sizing and cutting the replacement panels to fit the gaps you have cut out, is to make sure the holes between the front and back patch pieces are the correct distance apart to enable you to refit the door spring bracket. Don't be tempted to move a panel slightly to make it easier to weld.

Make sure you keep this distance the same as on the original panel!

With the old outer sills removed, the extent of the rust was clear. I could see how it was centred around some of the holes where the trim fixing screws were secured.

Rust around the screw holes

I could also see the extent of the damage caused by the ill-advised jacking attempt.

That jacking damage......

I went on and repeated the same exercise on the right and side of the car - removing front and back sections of the outer sill.

With the outer sills out of the way, I got a better view of the actual box section sills behind them. And it turned out that meant more work! So my outer sill replacement journey ends here for the moment.

Fuel Tank Removal

A lot of the recent work has been about building up to repainting the chassis. Another step on that journey was removal of  the fuel tank so that I could inspect, clean and repaint the area beneath the passenger seat. Given that the car had, by now, been laid up for 20 years, I was also expecting to have to replace the fuel tank because of internal rust.

The fuel tank revealed

The tank is hidden away beneath the rear seat and a protective cover. With the seats out, accessing the tank area was easily and simply a case of undoing all the bolts on the galvanised panel under the rear seat.

Cover panel over the fuel tank

The cover panel hinges towards the front on a simple scroll hinge and can be unclipped or slid out. With the tank exposed, I disconnected the wires from the fuel level sender.

Fuel level sender

I removed the Ligarex clip on the rubber join of the fuel filler pipe in rear wheel arch, and the Ligarex clip on the nylon breather  pipe at the tank end.

Curved pipe is the breather

The next task was to remove the fuel pick up tube from the tank. This goes into a curved guide tube in the tank, which steers the pick up tube down to a fuel filter. Over years, the pick up tube hardens and so it can be very reluctant to be released from it's guide tube.

Tank cross section. 'A' is the guide tube to 'F' the filter

Since the nylon pipe goes down a metal guide tube, on the outside of the tank there is an outer black rubber sealing tube over the nylon tube and guide tube spigot. This outer tube is a tight fit to provide a fume-free tank seal. When removing the nylon fuel pick up tube from the tank, it's important not to kink it as it can be brittle and so crack and leak. The difficulty is that as it is pulled from the fuel tank spigot, it has to be pushed through the sill box section beneath the rear passenger door on the right hand side of the car.

The pipe is secured along the sill, so those brackets needed to be removed to provide some slack. Removing the brackets only provides a limited amount of slack because the pipe passes through a hole in the 'B' post which retains the pipe close to the car body. 

With the fuel pipe free in the sill, I began to pull on the black rubber outer hose at the tank end -  and at the same time readied myself to feed the freed pipe through the sill. Unfortunately the pipe freed suddenly and, as I pulled it through the sill, it buckled and creased. I can't tell if it is is holed and will leak, but will not take that chance. Since the outer sills are off and the engine is out of the car, I might as well replace the fuel pipe. if only for peace of mind.

The tank is a tight fit in it's cubby hole and I've read several posts on social media and DS forums from people who have struggled to see how to get the tank out. I think the issue was difficulty in getting the tank past the brackets that hold the metal over-straps. I didn't have any trouble and I think that might be down to technique.

There are a number of packing rubbers around the perimeter of the seam of the fuel tank. In some places these rubbers are slotted and are just pressed on to the tank seam.

Slotted packing rubber on the tank seam

In other places the packing pieces are tubular and are held idown on top of the seam by simple folded metal tabs.

Tubular packing rubber under metal tab

The tank is secured in place by two metal straps.

Metal securing strap

These are effectively hinged at the back end of the tank recess.......

Metal strap and rubber packing piece

........and are screwed down at the front end.

The ends of the straps are screwed down

Undoing the long screw released the clip at the front. 

Strap and retaining clip
(photo credit: unknown)

The strap hinged back, releasing the rubber packing piece at the hinge end.

Packing piece at the hinge end

At the screw end, I was able to access another slotted packing piece pressed on to the seam.

Slotted packing piece under the metal strap

Withe the wires, pipes and hoses disconnected, the rubber bumpers removed and the straps undone, the tank should lift out. I think this is where some people have struggled. The front end brackets that the metal straps screw down to, are folded over the seam of the tank and get in the way.

The strap retains clip sits on the seam of the tank

They seem to be hinged, but can't be folded down as the tank is in the way. Even if they could be folded, that wouldn't really make any extra clearance to remove the tank. The solution is simple: with the rubber packing piece out of the way, the brackets can be pushed down vertically.......

The strap clip can be stood up

........then unclipped and completely removed.

Removing the strap retaining clip

This can be done with the tank in situ and then gives enough room to free up the tank. With a bit of wriggling to release the fuel filler pipe from it's tunnel in the chassis, the tank was free.

Fuel tank removed

So what did I find? Well, it all looked very good. There was some surface rust near the tunnel where the filler pipe goes. This was probably because of the ingress of mositure and spray from the rear wheel arch. I found telltale signs of mouse action. Almost certainly as a result of the car quietly sitting in a barn for 14 years.

Evidence of mice.....

Other than that the floor was rock solid. I will probably clean it out, but may not even bother to paint it.

Floor under the fuel tank

With the tank out, I was able to drain the fuel from it. The brass drain plug came out easily. These can be fused in place with the risk that the brass nut becomes rounded as you attempt to remove it.

Fuel tank drain plug

I was quite surprised to find that there was no fuel filter inside the brass plug. 

Without filter........
It wasn't rattling around inside the tank so must have been removed at some point in the past.

There should be a filter on the end of the drain plug

I was even more surprised to see that, although stale, the old fuel came out clean. No signs of rust and no obvious residue left inside the tank. I blew compressed air through the tank to remove fuel vapour. and put an endoscope camera inside for a better look. I was amazed to say the least!! The tank was clean and shiny inside. No signs of rust. 

The view inside my tank. Shiny!

Considering the age of the car and the number of years it sat un-used, I expected to find the tank a disaster. 

This is what I expected to see...
(photo credit: Carter Willey)

In fact I'd already bought a new replacement fully expecting to have to throw away my original tank. I may yet regret it, but I think I will keep this tank and sell the replacement tank to free up some funds. I will probably have to de-glaze the tank to remove any 'varnish' left by the old fuel, but now I'm worried about 'flash-rusting' so will leave things just as they are for the moment.

Another view inside the tank