Most of my cars use the Tranzit Blu. That product has a control button that solves that problem.  However, I don’t have that system in my 250SE, and I have a period radio to install in my Daimler that also doesn’t use it.

I figured finding a solution for the 250SE would also translate to the Daimler as well.  I didn’t want to modify the car in any way, or need to be constantly recharging something.

After some research, I found some basic Bluetooth controllers that use a button battery.   Those batteries should last for at least a year.   My phone should be able to connect to two Bluetooth devices.  The Bluetooth box at the back of the Becker, and this controller.

There were a lot of these controllers for sale. I wanted a small one that has buttons for previous and next track, volume and answer call.   I found one that was quite inexpensive on Ali express and ordered a couple.

I found it to work ok, although not perfect.  It pairs with my phone, and goes to sleep.  When it is sleeping, it wakes up when a button is pressed and re-pairs with the phone.  You can then press the button again and it will then do the function.

The biggest frustration is that it is not possible to rename the Bluetooth device in my phone, so once I have a couple, they will all look the same.  I’ve also not verified how long the battery really lasts, as the 250SE isn’t used as much as some of my cars.

Its possible to press the buttons without having to take eyes off the road.

while the controller comes with some double sided table, I managed to slot it in under the A/C unit. It is very unobtrusive.

A few years ago, I removed the 90’s CD player and installed a Becker Tribute Radio.   This is a modern radio that looks like an original Becker.   However, when the alternator died it presumably damaged this radio and it was never the same.   It did very strange things including sometimes running with the car switched off.   Since it could drain the battery, I had to remove it.    So there was not a gaping hole in the dash for the German car show last year, I quickly installed a Europa II Stereo from my Becker Collection as a temporary solution.

The Europa II in question was a mid production radio.   From its features it would have likely been manufactured between 1975 to 1977.   It made a good temporary solution as it needed a service anyway, and the Europa II being a single piece radio, it was a quick install.

After driving around for six months with the Europa II, it was clear that my car was no longer killing radios.   It was therefore time for something more permanent.    I could not install the correct radio due to the dashboard butchery, but I could install a DIN size Becker radio.   In addition a friend suggested I use the knobs off a slimline radio that would match the car better.   I ordered a set of those, and while I waited for them to arrive, went about thinking about which radio to install.

My first option would have been a lovely Grand Prix mono from 1971.    This radio is in superb cosmetic condition and the four band LMKUU markings would have fit in well with the age of the car.   However, I would have needed to fit an external amplifier to drive four speakers.  In addition, the auto seek ‘wunderbar’ feature is not working on this radio.

Next option could have been a very early Becker Mexico.   I have one of these from 1972 that could have worked.   However a built in cassette isn’t right for a 1965 car since that didn’t come out until 1971.   In addition, this early Mexico is a mono radio with a Stereo cassette player.   As I wouldn’t have been using the cassette, only the radio, this seemed a worse choice than the Grand Prix Mono.

Finally the other option was a Grand Prix Stereo.   This was appealing as is a top of the line Stereo radio that seems to make sense for a car like a W111 Cabriolet.   I have a couple of these radios, but the early ones need service.   By far the best is a 1974 model Grand Prix Stereo   I decided to go with this as it was in excellent condition.   Being a 1974 model, it had the smaller amp that would be easier to fit, and I had already put the plugs on for the small amp, since that is what is built into the Europa II.

I had this radio refurbished, so everything works.  I could have used an earlier model, but the early Stereo radios have a balance wheel on the front, but that dates them to 1971-1972.   In the photo below, it is sporting its original knobs.  The only downside is the Grand Prix Stereo is a two piece radio with a separate amplifier like a Mexico cassette.

The other Advantage of this radio was that I could plug in an external Bluetooth module into the port that normally would have accepted the external cassette player.   This port accepts a Stereo signal.     I tested the Bluetooth module on the bench and it works really well.   It only interrupts the radio signal when you want to play music via Bluetooth, and it has a hands-free calling function too.  In the photo below I am also testing the module in an earlier Becker Grand Prix Stereo.

One thing I had noticed from the Europa II was the whine coming from the speakers based on engine RPM.   I purchased a radio noise filter from Jaycar to assist with the install.   The actual installation was fairly straightforward.   The Europa II came out pretty easily.    I then wired in the noise filter and the separate amp for the Becker Grand Prix Stereo.     I managed to use cable ties to hook the amplifier onto the heater box.

The actual installation was fairly straightforward.   Switched power and ground went into the noise filter.   The noise filter the powered the radio.

I wouldn’t say the sound is perfect.  For better sound I would need to replace speakers and use an external amplifier with a high pass filter like I have in the 560SEC.   It does sound reasonable and looks great.   The slimline knobs look great but were a pain to get on.   Like the knobs on all the early radios they screw on rather than push on.  It can be really hard to get the tiny screwdriver in when the radio is installed in the dash.

Overall I am really happy with the install and how the radio looks in the dash.   The slimline knobs make a huge difference.

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There are lines from the oil filter housing that go to the heat exchanger, as well as coolant lines that come from the side of the block.    An example is pictured below.  The picture is not my heat exchanger.  It is a second hand unit available on eBay.   From all I read on the Pagoda forums, the M129 Heat Exchanger is quite effective.  The 250SL runs quite cool with it.   The heat exchanger is now NLA, but the part number is 000 188 44 01.

I would have been blissfully unaware of my heat exchanger except for a growing oil leak.     The oil leak was coming from the braided flexible oil hose that runs from the far side of the M129 heat exchanger to the oil filter housing.

When my mechanic investigated further, he also discovered that the coolant outlet on the engine block was corroded.

I started looking up what parts I needed to buy to fix the oil leak and make sure the heat exchanger was working properly.    On my car, the longer hose had a short metal section, the braided flexible hose and then another short metal section.    But in the EPC this was one hard line.   There was no mention of any other system.

I started doing some further research and I found a post on the W113 forum. It described how in the paper parts manual, there is an earlier setup which had been superseded. The older setup was never brought forward into the EPC.

In that section you had the two hard lines (127 180 00 27 & 127 180 02 27) plus the braided line (198 180 01 82).   This was replaced by 127 180 03 27 which was the single metal hose.  308 in the diagram above.  In case you’re wondering 127 180 01 27 is the shorter hard line for the other outlet of the M129 Heat Exchanger (302).   This never changed.

While I had the backup of taking the existing braided hose to a hose shop to have the ends re-used for a new hose, I first checked to see what parts were still available.   Since the braided house was first used on the 300SL, it is still available.   The surrounding hard lines are not, but mine were perfectly fine.    Additionally, the replacement part 127 180 03 27 is also still available.   Neither were particularly expensive.  Both are probably cheaper than having a hose company re-use the ends of my existing braided hose on a new one.

I decided to go with the 300SL part.  I had a few reasons for this.  Firstly, there is very little space around the M129 Heat Exchanger.  Getting a flexible hose in and connected with the engine in situ was probably going to be far easier.  This was going to save me labour time.   Secondly, the parts cost was less than half.  Thirdly, I figured the flexible hose had a bit of give in it for vibrations and parts not being perfectly aligned after 60 years.    And finally, I liked the idea of having 300SL parts on my car.

While the car was at the workshop, I had new rear shocks fitted and the power steering pump adjusted so it wasn’t so noisy.   My oil leak is gone. I’m also sure the heat exchanger working properly will help the car cool on very hot days.    I also learned a lot about a feature of my car I never knew it had.

On the way down I noticed how bad the ride was.   The car was quite bouncy and not very enjoyable to drive.   While the car didn’t do any long trips, I was using it quite a bit on short trips to troubleshoot the running issues, so it seemed strange that the tyres would be flat spotted.     I checked the pressures on the tyres and they were all fine, perhaps even a little higher than they needed to be.

On the way back I had the same issue even after slightly reducing tyre pressure.  I also noticed a crease on the tyre sidewall, it was very slight, but still noticeable.     As the tyres were 8 years old this year, I had planned to change them anyway, so I decided to get a new set right away.  I was worried that the tyres were starting to separate internally.

On the last set of tyres, I made a mistake.   Instead of looking up the original tyre size, I just replaced what was on the car.   This was wrong.   The tyres on the car were 195/70 R14.   This was too low profile.    Depending on the source, the tyres were originally either 185R14 or 195R14.    The technical data book for 1966 says 185R14 and the Mercedes public archive says 195R14. They also have some old bias ply sizes.   This is what it looks like my car was delivered with per the data card:  7.75 14 Continental.

185R14 is now a hard size to find.   195R14 isn’t hard to find in a light truck size, but almost impossible in a car size.   Light truck tyres are not suitable for a classic luxury car, they are going to provide a terrible ride.   However, 195/75 R14 is available in a few decent options.   This is very close to the original size and in my view a pretty good alternative.    I went with the Hankook Kinergy Eco 2 K435.  This is the same tyre I have on my 450SLC, albeit in a different size.   I’ve been quite happy with these tyres on my 107.

I went with five tyres in the end.   The spare tyre pre-dated my ownership of the car.   I couldn’t see a date code on it, and by the tread the tyre reckoned that from the tread it was from the late 70s or early 80s.   It looked quite good, but I wouldn’t have wanted to drive very far on it.   The tyre fitter also mentioned to me that one of the tyres had started to separate internally, so I’m glad I changed them.   Tyres shouldn’t be used if older than about 8 years old and mine were getting up to that age later this year.

As well as the tyres, I had the car aligned.   I’ve have a few issues with the car feeling like its wandering at speed.   I’ve had a few issues with older cars not being aligned against the right specs, so I photographed the relevant pages of the technical data book.    since fitting, I’ve only driven the car a short distance, but the steering feels better.

My first step was setting the correct advance curve for my engine.   Luckily the workshop manual has all the specifications I needed.    The first specification covered the static timing value for the ‘047’ distributor my car was equipped with.

This distributor was shared with the 250SE saloon and coupe, as well as the 250SL and some versions of the 230SL.      Next the manual also covered the advance curve.     The ‘047’ and ‘051’ distributors are a little different in this regard.   While they have a normal advance curve, they use a vacuum retard curve.   As far as I can tell, this was not emissions related, just a quirk of these engines.    It’s quite odd, as the curve for related engines like the 250S is totally different and does not use this vacuum retard.

I used the centre of the curve for my initial setting, adding 5 degrees for the static timing value.    Setting the vacuum retard was a little more tricky, as the add actually doesn’t really allow it, but there are settings you can use to ‘fool’ the system into doing retard, not advance.    The 123 ignition company provides such an example on their website, which I used.

The car started up fairly well, although idled quite high.    I took the car for the first test drive since fitting the new distributor.    The test drive showed a lot of promise.    I had none of the missing, stalling or stuttering that I had experienced before.    On the other hand, the car was pinging quite a lot under load.   I tried a few minor adjustments to see if that would help.   I used the app to set up the advance curve to be the bottom of the curve rather than the centre.   It helped a bit, but the car still pinged.

A couple of days later when I had more time, I started by checking the timing with a timing light against the values in the distributor.  To make sure I was checking static timing, I zeroed out the advance values in the app below 3,000RPM. Immediately the error was apparent.   I really should have checked this first.   I had assumed my static timing was at TDC, but actually I was between 15 and 20 degrees BTDC.  No wonder the car pinged.   I loosened and rotated the distributor until it was at 5 degrees BTDC, per the factory setting.    A byproduct of this was the idle went down a bit too.

Based on this, I then set the advance curve per the centre of the curve on the page.     I took the car on another test drive.    This time, the pinging was gone.    Since this test drive was at 10pm, and it was only 15C out, I left the settings where they are.   In the future, I will take the car for a longer drive on a hot day, and experiment with advancing the timing a bit, for example to the top of the curve.

During these test drives, I was able to have the 123 ignition app up on my phone to see what the distributor was doing.    It’s quite useful!

The other positive thing was that the car ran well on this test drive.  Again, no missing, stalling or stuttering.   While the problem was intermittent, it would have normally manifested itself in the two drives I have done so far.   Things look extremely promising.

The car is having a power steering leak fixed next week, so after that I will be able to take it for a longer test drive, and further adjust the settings on the 123 ignition distributor.    So far, the 123 ignition has exceeded my expectations.    I also need to mount the coil properly and tidy up the leads.    Separately,  I found out that the residue around #5 spark plug is likely just grease coming out of a fitting on the side of the head.     Based on that, and since the car is running well, I have not changed the spark plugs so far.   My next step is really to put some more miles on the car and make sure the problem really is gone.

I spoke to the local agent for 123 ignition, and based on that discussion, I checked the distributor in the car.  My car being an early 250SE (10/65) has ‘0 231 116 047’.   This lined up with the technical data book, indicating the distributor is likely original.

The ‘047’ distributor lined up with the Mercedes-6-R-V distributor.   This distributor was also used on late 230SLs.   The Mercedes-6-R-V had a curve (D) to replace this.    I was also advised to buy a new coil, and I went with a Beru blue coil.    The requirements were that it didn’t use a ballast resistor and was at least 3 Ohms.    Since I was trying to rule out the ignition system, I also ordered a new set of Beru leads.

The next day the local agent for 123 ignition contacted me to inform me that he didn’t actually have the Mercedes-6-R-V in stock, but he would be happy to upgrade me to the Tune+-6-R-V-M at no extra charge.    The tune plus does not come with set curves, but instead is fully programmable via a bluetooth app.    The app also lets you set a pin and use it as a immobilizer too. This was a very kind offer, and I was very happy to try the programmable distributor.

Last week I started to install the 123 ignition distributor.   I reviewed the manual, and also watched the video from 123 ignition.  It seemed fairly straightforward.

The first step was to set the car to TDC.  I took the lazy approach and used a remote starter switch to turn the engine on the starter.   Next, I removed the cap and ignition leads from the car.   I was able to confirm that I was at TDC but also checking the rotor was pointing to the marking for #1 on the distributor.

It was a simple task to remove the old distributor.  I also removed the ballast resistor (not needed with the 123 ignition).   I couldn’t get the old coil out of the bracket, as the screws were rounded off, so for now I just put the new coil next to the old one.    The new distributor seemed to slide in quite easily.

The next part of the installation is to time the distributor.     The distributor has three wires coming from it.    There is a red wire, that goes on the positive side of the coil, along with the switched power from the car.    The blue wires is a ground and the black one goes on the negative terminal of the coil.    These wires do not come with ring terminals, which you need to fit yourself.   To do the timing, you only connect the red and blue wires.

The procedure is that you first turn on the key, and then turn the body of the distributor anti-clockwise until the green light comes on.   I did this, but I was a bit perplexed as the green light only came on when the rotor arm wasn’t quite lined up with #1 on the cap.   After trying a few times, I wasn’t able to get it to line up perfectly.    I decided to get it as close as I could and try it.   To try it, I tightened up the distributor, fitted the cap, fitted the leads, and fitted the back wire.

I tried starting the car, and it wouldn’t run.   By this time it was about 11pm, and I was a bit frustrated so I went home.

Over the weekend, I found a lot of people on the W113 pagoda forum had fitted 123 ignition distributors to the pagodas.   These were primarily people who owned US model 280SLs with the emissions system that retards the ignition.

Today I went back to the car for a fresh look.   I wanted to start from scratch, so I attached my remote starter switch and took off the distributor cap to find TDC.   I was able to use the scale on the crank pully and looking at the cam through the oil cap to find TDC.    In doing so, I noticed something important.   When turning over the engine, the rotor arm was hardly moving.   Obviously the car isn’t going to run when the rotor arm does not move.

This prompted me to think of something I had read on the pagoda forum.     Some members had reported that the clamp that tightens the distributor fouls on the distributor body, and stops it properly engaging the engine.   To solve, a few posters simply turned the clamp over, so it faced down.

The picture above shows the camp before I turned it over.    The portion where the screw goes into the camp is what fouls on the distributor.    With the clamp inverted, the distributor went in properly and I was able to set the position correctly so the rotor arm was pointing to #1.

The green light indicated that the distributor was in the correct position.

I tightened up the distributor, fitted the cap, leads and the black line.   This time, the car fired up properly and seemed to run quite well, albeit with a very high idle.   That was expected, as I had not yet connected the vacuum line.   The ‘047’ distributor uses a vacuum retard.   The factory vacuum line screws in, but I was able to extend and adapt the vacuum line with some joiners from the 420SEL parts car.

With the vacuum line connected, the idle settled down, although it was still a little high.

When fitting the leads, I noticed that there was some residue under the spark plug for #5.   Perhaps some leakage.  Once I get everything working properly here, I will change the plugs too, but I want to focus on one thing at a time.

From there I focused on tidying up the wiring and leads, so I could take the car for a test drive and play with the tunable ignition curves.   The 123 ignition app is quite good and shows various stats that you can monitor while the engine is running.

Tomorrow I will take the car for a test drive and see how it goes.

Update 6/10/23:  Link to part two.

The challenge is that these are intermittent problems, and so hard to diagnose.   I started by checking the basics – the fuel filter, tank and so on.  I also changed the plugs.  This had no impact.    My mechanic thought it was ignition related, so we’ve changed most of the wear components of the ignition system – points, cap, rotor, condenser, coil, suppressors and so on.   When the car is running well, its running better than ever.   But when it runs poorly, it stalls and stutters.

Based on that, I’ve got the car booked in again for another look early October.   I haven’t been driving the car much this year, as its just not very pleasant to drive when its running this way.   This is a shame, as I normally really enjoy driving the W111.

I took the car out again last week to see how things were going, and it ran quite poorly.   It stalled a couple of times and felt like it wasn’t getting enough fuel.     I’ll have to see how the visit to the mechanic in October impacts the car.   The more I drive it, the more I think its fuel injection related.

I had hoped to take it on a drive to Victoria I am doing in November.   Even if it seems fully fixed in October, due to the intermittent nature of the problem, I will probably not take it on that trip.   I’ll likely take the 560SEC instead.

While I was there, I also removed the Becker Tribute radio.   I had been having problems with this also.   The radio would just lock up and stop responding to inputs.   I took it out last year and even sent it away to Classic Auto Sound to be checked.   They kindly looked at it, and on their bench could find no fault.    I don’t know if its the car or the radio, but it stopped working for me earlier this year.

I took the radio out to do my own testing and put in one of my Beckers in its place.    Its a mid series Becker Europa II.   Its a radio that I need to have serviced anyway, so if my car is eating radios its better to try this one.    While the serial number tag has been lost, this radio would have most likely been manufactured between 1974 and 1976.    It has the newer style of speaker connectors, the larger stereo light and other features that place it in this date range of radios.    I don’t think this is the radio I will put in the car long term, but it looks great in there.    Even if the car is still running poorly, I plan to display it at the all German show later this year.

The Becker Europa II has a crack in the dial scale, but reproduction dial scales are available.    The advantage of the Europa II is that it is a one piece unit, so very easy to fit.    This era of Becker’s are DIN sized, but use their own mounting system of metal rods to hold it in place.   Those rods are often missing with second hand backers, but not hard to find.     The radio is installed in the dash without the knobs or the dial scale.    Outside the two knob shafts are the slots for the rods which are easily inserted and tightened up.     While I was there I also threw in a USB charging port.   The modern charger is very ugly in the beautiful W111 dash.

The W111 alternator is supposed to be a 35A model, and the previous alternator had a 35A part number.   It kept up much better.     I can only assume that either the previous alternator was rebuilt at some point to make more power, or the new one wasn’t a good rebuild and was making less power than it should.    I had already replaced the external voltage regulator to rule this out.

That W111 alternator barely being able to keep up with the car’s power needs made me reluctant to take the car on long trips.   I also wondered if it had anything to do with the car’s recent running issues.   With the charge warning light on, was it even making enough power at idle for a strong spark?

I decided to source a better alternator, and purchased a Bosch rebuilt unit from the USA.   Instead of going with the standard w111 alternator of 35A, I went with a 55A alternator.   This is a bolt in replacement that still uses an external voltage regulator.   The one I went with is used on the late 280S/SE W108 and the /8 models.     Other than a slightly different plug, you would hardly notice the difference.   I didn’t want to change the wiring to go with an internally regulated alternator.

The Bosch rebuilt units have a good reputation, and this W111 alternator looked almost new.

As can be seen in the picture, the rebuilt alternator didn’t come with a pulley.   When my mechanic was removing the pulley off the previous alternator, he discovered that it wasn’t assembled properly.    They had used the wrong pulley, and to make it fit, omitted the little key that prevents it from spinning on the shaft.   It had been tightened up, so wasn’t obviously slipping, but who knows what was happening under load?   My mechanic had another dead alternator with a good pulley he was able to use.

In any case, there was a huge difference in performance with the new W111 alternator.   Even with headlights on high beam, AC on max, I was still getting just under 13 volts at idle.   It would drop down into the high 11s before at times.

The one thing that it did not improve which I was hoping was the radio performance.   I’ve been having all sorts of strange behaviour with my radio.  I event sent it back to the seller to test and it worked fine on the bench.   I was hoping that a better and more consistent power supply might fix these issues, but it hasn’t.   More investigation to do there.

As well as the W111 alternator, the car also had a regular service and a tune.   Previously the idle was very low and it would be almost stalling in gear.   Now its driving really nicely – better than it has in a couple of years.   Its a really nice car to drive again.

While it was in the workshop, I also had the subframe mounts checked.   The front end feel is a little vague.   The subframe mounts made a big difference on my 450SLC.   The verdict was they were fine.

I’ve been happy with the radio in the car, and would recommend it to anyone who had their dashboard modified like this.    Recently, I’ve been seeing some strange behavior on the radio and it was getting less and less usable.   Classic Auto Sound, the company who sold it to me have been very helpful trying to trace what is going on.

The problems first started when on a long drive, the radio would stop responding to the buttons or knobs.   It would just keep doing what it was already doing.   In that case, it was playing off the USB key.    It would also sometimes not turn off properly when I turned off the ignition switch and removed the key.    At first this happened only on long drives, but in the last couple of months I couldn’t even power the radio on at all.   It would always be just stuck in the clock mode.   It would be like that even with the key off.

Classic Auto Sound suggested it might be the left knob shaft failing.   The suggested removing the radio, and connecting the plug from the right knob into the left side of the radio.    I did that, and all of a sudden I could turn the radio on and off again.    Based on that Classic Auto Sound sent me a knew shaft at no cost to me.   That’s great service considering the radio is a couple of years old now.

It’s pretty easy to swap out one of the shafts – I had it done in about 15 minutes.   I took the car on a short drive, and everything was well.       A couple of days later, I took the car on the MBCNSW July Night Drive.    The meeting point is about an hour and ten minutes away from where I live.   About 45-50 minutes into the drive, I noticed the radio stopped responding to inputs from the knobs.   I was using the bluetooth function, so I could still change tracks from my phone.   Normally you can use the radio knobs to do this.   I was also unable to change the volume.

While we were waiting for the final cars to arrive, I disconnected the battery and reconnected it.    The radio was fine again.   However, on the actual drive, it was a much shorter time before it stopped working again.   The drive was about an hour and 20 minutes and during that time, I had radio through my phone, but I could not just the knobs.    I didn’t bother disconnecting the battery while we got a snack at McDonalds at the end of the drive, I just paused the music with my phone.   The radio stayed on pause the whole time I was in McDonalds (about 20 mins).  It then played the entire way back, again through my phone with the buttons doing nothing.   Once I got back, it took disconnecting the battery to turn it off.

I emailed Classic Auto Sound again and asked if they had any more ideas.   It was suggested that I check if I have the yellow (constant power) and red (switched power) lines correct.   I checked those, and they were.  Voltage was 0nly present on the red wire with the key on, and was always present for the yellow wire, with the battery connected.

Once confirmed, It was suggested that I check the behavior of the switched power, as the radio isn’t supposed to work without it.   In order to be able to do that on a long drive, I’ve rigged up a voltage indicator to the switched power source.    It was less than $10 at Jaycar.    I’ll now be able to watch what happens on a drive when the radio is working fine, and if there is any difference when it is not.

The little voltage meter comes out from behind the dash, so I can see it on top of the transmission tunnel.   Next step is another longer drive in the car to see what is happening.

I knew the hoses were only a year old on the 560SEL, so the issue was likely to be with the caliper.   The hoses were probably due for a change on the 250SE, so could have been either issue there.   Based on this, I checked the caliper types and ordered the appropriate rebuild kits.   I also ordered a set of hoses for the 250SE.   I had to double check the electronic parts catalogue, as the rear hoses are not the same for each side on my car.

The 250SE went first, and while the hoses were due for replacement, all four calipers were pretty bad.   The difference in feel in the brakes is immense.  The first few times I drove the car, the pedal was so easy to push it was almost like there was something wrong.   In addition, I had some more work done on the ongoing stuttering issues I am having with the car.   My mechanic was able to tune it up as best he could but he thinks I’m close to needing a rebuild for the mechanical fuel injection pump.   Not only is it causing these odd fuel delivery issues, but it has an oil leak out of the back.     He also suggests I keep my eye out for a good used thermal time switch (part 001 545 92 24).  Cold starts are very slow.

Next was the 560SEL.   In this case, the fronts were fine, but the rears were pretty locked up.   While he was there, I also had the front shocks replaced.   Fixing both has made a big impact to how the car drives.   Again, the pedal feel is much better even with just the rears done.   And the ride over bad surfaces is significantly improved from the shocks.   Those Pedders shocks were really low quality and were already knocking despite not being that old.   They really ripped off the previous owner of the car.

I figured after having three pairs of brake calipers rebuilt, I was done for a while.   Turns out, I wasn’t.   Around the same time, the brake pad wear indicator lit up on my 560SEC.   Assuming this was a routine brake pad change, I got to work.   I don’t normally detail routine maintenance on this site, so wasn’t planning to feature anything about this.   However, when I had the first pad out, and it had most of the wear materials left, I started looking more closely.   Turns out only one piston has been working and that side is mostly down to the backing.

While I was there, I also measured the thickness of the rotors to see if they need replacement.   They look pretty old and crusty, so its quite possible they do.   Instead of swapping the pads, I put the old one back in.  I will book in this car to have the calipers checked.   I’m pretty confident I’m going to need another set of rebuilt Mercedes brake calipers on this car.    Luckily, I have a set of Bendix rebuild kits of hand that I purchased but didn’t need for the 560SEL.

Based on this experience, I expect that a vast majority of classic cars are driving around with brake calipers that are not functioning as they should.   They still stop the car, but performance is not as good as it should be.   This is going to be particularly prevalent in cars that are not driven regularly.   As much as having the calipers rebuilt is not a cheap exercise, good performing brakes are not something I am willing to compromise on.

Finally, while I was under the 560SEC, I swapped and adjusted the SLS control rod.   The rear ride height was too low, so I used the same technique as I did previously with the 300SE.    The height is better, but I think I need another couple of cm of height to have it back to factory.   The old control rod was starting to fail, so I used the one I had on hand for the 280SE and will order another one for that car.

In all this, I’ve found that when having a bunch of cars, I have the same issues on multiple cars at roughly the same time.   Part of it might be that having an issue on a car makes you more aware of it on others, but in the case of needing the rebuilt Mercedes brake calipers, I’m not so sure.