560SEC outside temperature display

Last week I fixed the outside temperature LCD on my 300SE. Today it was time to fix the 560SEC outside temperature display as well. In my previous post I covered the details of where I purchased the replacement LCD panels. This same repair should also work on W124 and W201 models of the same vintage. I understand there are minor variances, and that the LCD changed slightly in later years. Both types are available.

I found a few things to speed up the process while doing the second car. Firstly, the instrument cluster does not need to be unplugged. It […]

Cocomats for the 560SEC

A couple of months ago some of friends of suggested a group order for Cocomats. This coincided with a 15% off sale and shared shipping. Cocomats are a floor mat made from coconut fibre and were a period accessory during the 1950s and 60s. They were quite popular with Mercedes-Benz, Porsche and other manufacturers. I have wanted to replace the generic rubber mats in the 250SE for a long time. As well as the 250SE mats, I also purchased a set for the 560SEC.

I thought long and hard about which car would be best for the second set. In […]

M117 fan controller prototype

A couple of months ago I tried a modification on my 560SEL to trigger the auxiliary cooling fan earlier. The primary reason for this was to provide adequate air flow over the A/C condenser in stop/go traffic. The W126 A/C was designed for R12 refrigerant and is marginal at best with R134A. I used a resistor to trick the fan into running at a lower temperature. It worked, but the temperature kick in was a bit higher than I wanted and the wiring was messy. I thought a better solution would be to build a proper M117 fan controller.

The […]

W126 Monovalve eliminator – part 4

I have now completed the installation of the Movovalve elimination kit on my 560SEC. So far so good. Most importantly, I don’t have heat when I don’t want it, but it is available when needed. In the last installment, I completed the routing of the cooling hoses. From there I installed the radiator and ensured the cooling system didn’t have any leaks. The final step was to set up the vacuum solenoid so it could control the heater valve.

The very rough diagram below outlines how I adapted the kit for the W126. Note the diagram is not to scale […]

Installing a W126 radiator

Today’s job was installing a W126 radiator into my 1987 560SEC. I had previously sorted out the cooling hoses as part of my monovalve eliminator install. I was just waiting on a few extra parts I had ordered to begin this job.

Firstly I decided to replace the coolant reservoir tank. My current one is not leaking, but the plastic was quite discoloured and looked a bit white around the hose entry. Genuine Mercedes coolant reservoirs are still quite inexpensive, and you never know how long that will continue. Best to change it now. I was already planning to replace […]

Replacing W126 cowl covers

I had previously removed the W126 cowl covers to clean the drains. Now they are clean and I have replaced the ABS module bracket, they were ready to be re-installed.

Before I did so, I had some new parts to install. The first were the rubber boots that cover the windscreen wiper shafts. On most W126 cars they are almost non existent. On my 560SEC, I had the remains of one, and the other was completely gone. The picture below shows the two new boots along with the remains of what was left on my car.

Second was the rubber […]

Cleaning W126 cowl drains

As part of the installation of the Monovalve elimination kit, I needed to remove the ABS controller bracket. The bracket was in the way of the coolant hoses. I order to remove it, I needed to remove the W126 cowl drains cover. This is great opportunity to inspect this area and clean it. Cars that have parked outside often have debris here that causes rust.

In order to remove the W126 cowl drains cover, the seals at the firewall and windscreen must first be removed. In the photo above, I have removed the seal on the firewall but not the […]

W126 Monovalve eliminator – part 3

I have been working on a project to eliminate the monovalve from the climate control system in my 560SEC. In the last part I had almost completed the cooling hoses required for the job. I had mostly worked out hose routing I was looking for – which was combining the dual outputs from the heater core into a single hose where I could place the new heater valve.

Looking further my design wasn’t going to quite line up. Once I put the elbow piece on the end, it was too long and the hoses were bent too much. I didn’t […]

W126 low pressure hydraulic hoses

My 560SEC has been leaking from the power steering and self leveling suspension. In both cases, it is obvious that (at least some) of the leakage is coming from the low pressure hydraulic hoses. It is possible there are additional leaks in the steering, but fixing this obvious one is a good place to start.

I had looked at doing this job a couple of months ago. I quickly saw it was quite fiddly and as I was planning to use the car the next day, I decided to put it off. Once I realized I would be removing the […]

W126 radiator removal

As part of the work I have been doing to the 560SEC, I have removed the radiator. The radiator was leaking from the top tank and appeared to be original. It was an IMI unit which was one of the OE suppliers and had a 1987 date code on it. W126 radiator removal is fairly straightforward.

Fist step is obviously draining the coolant, and there is a drain valve at the bottom of the radiator. The coolant will drain must faster if the radiator cap is off. I am really happy with how clean the coolant is, and how little […]