Since I had the car in the air, I used the time to check what calipers I had on the car.   On the front, I had Bendix and on the back I had Girling.   Once I dealt with the fuel delivery issues, I planned to have the brakes sorted out.

Based on what I saw, I ordered rebuild kits for the front calipers, plus pads, rotors, wear sensors and all four brake hoses.  The mechanic I was using to do the job also suggested I get wheel bearings while he was in there.

Having seen the condition of the fuel tank, it is obvious that this car has seen little use in recent years.   It is pretty typical of lower mileage cars that don’t see much use to have binding or sticking brake calipers.   This is another reason to use classics regularly and have the brake fluid changed every couple of years.

I suspect a fair number of seldom used classics could do with a brake caliper overhaul.

It took me a lot longer to deal with the fuel delivery issues than I had anticipated.  The car finally went to visit the mechanic this week.  I also asked him to look at the A/C as it was no longer cold.

I got the car back today and the brake feel is transformed.  He told me that he had to replace three of the four pistons in the calipers as they were all corroded.  After seeing the inside of the fuel tank that does not surprise me.   He also changed a valve in the A/C and recharged the system.

Today was around 40C and the car had been sitting outside the mechanics workshop in the sun for a few hours when I picked it up.   It was a good test of the A/C.   On the move, it was quite good, but the performance in traffic was not so great.  I’m not sure if the aux fan is kicking in enough, I’ll have to look at that.   On the W123 diesel the fan is only connected to the A/C pressure switch, not the coolant temperature like some of the petrol cars of this period.  This means my trick of adding a resistor to make the fan kick in more aggressively is not as easy to do.

I’ll first make sure the fan is actually working properly, and if it is, perhaps add something that causes it to kick in more aggressively.    I know it did before, but it is possible a relay or fuse has blown since.

The 240D is now running and driving better than ever and I am looking forward to using it more in January.

The post W123 Front Brake rebuild appeared first on Classic Jalopy.

I stopped by Repco and bought a bottle of the Penrite Diesel Biocide.   It claims to kill bugs in the fuel and separate water and diesel.   The bottle had various concentrations, but I went for the ‘shock treatment’ – 200ml to treat about 50 liters.    Apparently when it is working, the dead algae can clog up the fuel filters.   I checked the pre-filter after I arrived, and there was definitely some algae caught in the filter.   I don’t know if this is the product working right away, or more from driving 150km yesterday after changing the filters.

In any case, my plan is to try and run most of this fuel tank through, changing the pre-filter if I need to.   Once the tank level gets low, I will drain the rest of the fuel and replace the strainer.   I did a quick check of the fuel tank with my cheap boroscope.  The tank is three quarters full, so I couldn’t see too much, but the walls were generally clean, with some minor black spots in places.   The black spots are likely the algae.

Next, I put the car up on the hoist to check a few things.   My hoist was out of commission for a while, and was finally repaired recently.   Putting the car up in the air, I was really impressed with the condition underneath.   There was no trace of any rust or any damage.   This is in keeping with the overall condition of the car.   Everything looked in pretty good condition.   The fuel strainer had been out before, and the fuel hoses were fairly new.   I also checked he bottom of all the doors and they are in excellent shape.

On the downside, the brake hoses looked pretty old, and the shock absorbers are Monroe, not Bilstein or Sachs.  They seem in decent condition though.   While I was inspecting things, I noticed the steering shock looked a bit old.   I had a spare one on hand, so installed it.

While the car was up in the air, I had a few other things I wanted to do.   First was to clean the water drain for the fuel tank filler.   I had tried from the top, and had not been able to push the debris out.   Pushing a long pipe cleaner up from the bottom managed to clear the debris.

Next I wanted to see if the brakes were grabbing.   A few weeks ago, I noticed the car was quite hard to push.   Yesterday, I noticed the brake pedal get a bit soft after a lot of stop/go traffic.   The first test was to see if the wheels spun freely.   The rear wheels do, but the front wheels had far more resistance than I would like.

Next test was to see if a few hard applications of the brakes made any difference.    The rears were fine, but the fronts were even harder to spin after a few presses of the brakes.  I also wanted to check if the rears were doing anything at all.   A long golf umbrella was useful to press the brake pedal while spinning a rear wheel.   I was able to stop the wheel, and it spun freely after I released the pedal.

Based on this, I want to change all the hoses, and the front calipers will likely need a rebuild.   Mercedes used multiple suppliers, so I had to inspect them.   The front calipers on my car are Bendix, and the rears are Girling.   The Girling calipers don’t seem to be all that common, so its probably just as well that my rears are fine.   Most of the rebuild kits seem to be for ATE or Bendix.

I had to remove one of the rear wheels to inspect the rear calipers, so I gave that wheel arch a good cleaning.   For the other three wheels, I cleaned the wheel arch with the wheel on.   I had a huge pile of debris on the floor by the time I was done.    I also noticed that all four of my jacking points was clogged up with wasps nests.   The jacking points are in good condition, and are now without dead wasps.

The post 240D algae, hoist inspection and minor jobs appeared first on Classic Jalopy.

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.

The post Rebuilt Mercedes brake calipers appeared first on Classic Jalopy.

There are a few parts on Mercedes of this era where multiple suppliers were used for the same part.   W126 Brake calipers are one of them.   Another example is window regulators and motors.   In the case of brake calipers, the different suppliers are interchangeable, but the rebuild kits are different.   Calipers are supposed to be the same brand on each axle, but front and rear can be different.    The window regulators are a similar story.  You can replace the whole regulator and motor combination, but if you’re only changing one, it has to be in the same brand.

The two suppliers of W126 brake calipers were ATE and Bendix.   Other than the series 1 SEC, you could get either ATE or Bendix calipers on your front or rear axle.   To order the rebuild kits, I needed to know the brand.

The easiest way is to remove the wheels and check.   The ATE and Bendix calipers have a different arrangement for securing the brake pads.     In my case, this was a bit harder.   I had just had an operation where I wasn’t supposed to lift more than 5kg for the next two weeks.   Luckily, my little boroscope was good enough to get in and look at the caliper.   It wasn’t possible to see the pads, but I could see the brand stamped on the outside.

Looking at the caliper alone is not immediately apparent, but if you check the company logos, its obvious what you’re looking for.    In this case, I had Bendix calipers on the front axle of my W126.    The fronts are harder to examine than the rears, as the calipers are much larger.   Getting the boroscope down to see the rear caliper logos was much simpler.

In my case, ATE calipers on the rear.    I’m not sure if I will need to have the front calipers rebuilt, but I want to have the rebuild kits available just in case.   Kits are available for both types, bu the ATE kits are much more accessible, and available from different brands.   The Bendix kits were much harder to to find, and 4x more expensive.

Next time I have the wheels off the other cars, I am going to note down the caliper brands.   Even if you don’t source your own parts, it’s worth telling your mechanic what you have, so they order in the right rebuild kits before you arrive.

The post Identifying W126 Brake calipers appeared first on Classic Jalopy.

I have since found out that I made a pretty stupid mistake.   Instead of checking the new parts properly, I used the old ones to determine how they should fit.   In this case, I fitted the calipers based on the position of the old ones.   If I had checked the part numbers properly, I would have seen they were on the wrong sides.   Additionally, if I had used even a modicum of common sense I would have seen the bleeders were facing down, not up.     Why is this a problem?   Having the bleeders facing down means it is pretty much impossible to bleed the brakes.   Instead of pushing the air out, the fluid will just run out leaving air in the calipers.

The brake shop first put the SLC rear calipers on the right sides.   Then they made up new hard lines for the rears to go from the hose to the caliper.     After that, they changed the hoses.   The fronts were not much of a problem.     They had the same problems I did with the rears – no matter what they tried they could not undo the fittings.    I suspect that due to the extreme heat from the sticking rear calipers, the metals were almost welded together.

In summary,  I have an entirely new rear braking system.   New calipers, rotors, hard lines on both sides and hoses.    I also have a new master cylinder and front hoses.    The brakes feel great, and now the brakes are not dragging, the car feels more lively.

Incidentally the shop I took the car to has recently done some work on a 50,000km 450SLC.   They commented that mine rode better and seemed to have more power.   Not bad after 300,000km.

The post 450SLC Dragging rear brakes – part 3 appeared first on Classic Jalopy.

The first thing I found was that it was quite hard to remove the old rotors.   Not only were the rotors rusted to the hubs, but the old rotors was catching on the handbrake shoes.   I was able to turn the wheel by hand, but I think it was dragging a little.   It took a couple of huge whacks to free the rust on the hubs, and a lot of pulling to get them over the shoes.

I used a wire wheel to clean off some of the rust on the surface.  After that I applied some copper grease to stop it rusting in place next time.     Putting on the new rotors was almost impossible.   The handbrake shoes fouled on it quite badly and I had to adjust the handbrake shoes quite a lot.  Not just a few teeth, but probably a full turn.   I wonder if this was also part of the dragging?     Before I had adjusted the handbrake, I could not turn the new rotor at all even with two lug bolts at a long pry bar.     After the cleaning the braking surfaces, I was able to fit the new rotor.

At this point I also bent and fitted the new hard line I had damaged in part 1.   The lines do not come pre-bent and I so purchased a bending tool.  It is important to do more than minor bends with the tool as you can kink the lines and impair brake function.

The new 450SLC rear caliper fitted quite well, but there was a problem.   The new caliper had a slightly different place for the brake line than the old one.   Other than that, it was almost identical.      I did some research and found the source of the problem.

For one reason or another, Mercedes-Benz decided not to equip North American 450SLCs with the anti-squat rear suspension.   I imagine the decisions was based on the lower power output of those engines.   It is a strange decision though, as while the power is lower, there is still plenty of torque that is the main cause of the squat on acceleration.    Not equipping the cars with this suspension also meant a different arrangement for the brakes.   On the rest of world SLCs, there is a brake hose that connects the hard line from the car to another hard line that brings it to the 450SLC rear caliper at the front of the rotor.   This is the system that my car is equipped with.    On the North American cars (and the 350SLC, 280SLC etc), there is the normal arrangement of a hose from the hard line right into the caliper.

This is why the brake hoses I purchased first time around had a male/female arrangement and these new calipers had a slightly different arrangement for the brake hose.   The brake calipers I have, are part number 1234200583 and 1234200683.   The new correct brake calipers for my car have a 126 part number.   These calipers are far more expensive than the 123 part number 450SLC rear caliper.

On the passengers side I was able to get the hard line to connect to the caliper.   I am a bit concerned that it is very close to the bump stop.   On the drivers side, I was not able to bend it the way I wanted and it rubs on the bump stop.   I don’t think this is very safe as a large bump could damage the line.

From looking at the caliper, I think a new (slightly longer) line could be fabricated that clears the bump stop and connects to the caliper.   I don’t really have the ability or tools to do this, so I will take the car to a brake specialist.  This should be the best way forward rather than getting a new set of calipers.   I was also unable to get the hose off the drivers side, so will have them do that at the same time.  What they found and the w9ork they did is covered in part 3.

I bled the brakes, first with my vacuum pump and then had a friend help me bleed the brakes further with the traditional method.   There must be a small amount of air left in the system as the pedal is a little spongy.  I didn’t re-bleed as when the new lines are fabricated they will need to bleed in any case.

I also tested the handbrake and it is able to stop the car and is not dragging.

My final task was to fit my new MBCNSW grille badge.   I put it on the opposite side as my Mercedes high mileage badge.   Looks pretty good.

For what should be a simple job, this one has taken a long time.   I’ve probably spent more than two full days on it.

The post 450SLC Dragging rear brakes – part 2 appeared first on Classic Jalopy.

Last time I took the car on a longer drive, the noise was getting worse, and I noticed after I returned the rear wheels were hot to the touch.   Too hot to touch.    I realized that my noise had been dragging rear brakes all along.

Both sides were hot the touch, so it wasn’t just one bad caliper.    I went back and checked my maintenance records for the car and saw that the brake hoses were last changed in 2003 when I purchased the car, and one of the hoses changed again about two years after that.  16 years is about all the life that can be expected form these hoses, so I decided to replace them.   I also thought it would make sense to replace the master cylinder, as it is more likely to be causing dragging rear brakes on both sides.     Unlike when I had a similar problem with the Jag, the brakes were not locked hard on, just dragging.

Today, I did some further inspections.   I removed the rear wheels and looked at the condition of the calipers, pads and rotors.

The rotors were still within the spec from the workshop manual.   The hoses looked old, and not particularly flexible.   It was also quite hard to push in one of the pistons to remove the pads, even with caliper disconnected from the brake system.     This led me to remove the caliper for further inspection.

It was the same story on the other side.   Removal of the calipers showed that the heat had made the seal rather crispy.

These calipers can be rebuilt.  I may just replace them as the pistons don’t look great and the heat may have done other damage.   I am not sure if it is to do with the heat, or the 16 years on the car, but I found it almost impossible to remove the flexible hoses.  Even using the flare nut wrenches I managed to damage one of my hard lines.   I have liberally soaked the other side in penetrant to see if that will help when I get the new calipers.

While I was at it, I also replaced the master cylinder.    The brake fluid looked pretty good from a visual inspection.   I was quite surprised how much vile black fluid there was in the rear chamber of the reservoir once I removed it.   This is even after a flush about 18-24 months ago.

Some stained old shirts helped me protect the paintwork from the brake fluid.   In contrast with the flexible hoses in the rear, the lines were easy to remove from the master.   The coolant expansion tank needs to be unscrewed to get the master out. It does not have to move very far, so it does not need to be emptied.

Next steps are to remove and replace the hoses from the rear, fit new calipers to the rear and replace the front hoses while I am at it.   At this point I do not have any indication that the front calipers need to be replaced or rebuilt.  This is covered in part 2 and part 3.

The post 450SLC Dragging rear brakes – part 1 appeared first on Classic Jalopy.

When I still had the car in the USA, it was worse, the brakes would decide to lock on, and they would get to the point where the car was immobile for 5-6 minutes until they finally decided to release.  I was stuck by the side of the road on quite a few occasions.    At that time, I had a complete E-Type brake overhaul.  The master, servo, fluid, brake light switch etc were all changed.   This made it much better – for a while I thought it had gone away, but a few months later it started happening again just a little and the brake light switch was also staying on again.     The brake light switch was replaced again and an adjustment was made with no other improvement than the brake lights working again.

This time, the problem looks to be solved.   The front brake calipers were rebuilt – they were quite rusty.   In addition, the master cylinder that was put on in 2011 was not working correctly, and flexible lines were replaced.   Not only have I done the full E-Type brake overhaul, I have re-overhauled some items!

While the car was in the shop it also had the top wishbones replaced as they were worn.  I also had the cam oiling tube cleaned, and a few other minor adjustments.   In addition, a Pertronix electric ignition installed.

The result of all this is the car is better in every way.   The brakes have never worked this well.  The electronic ignition makes the car much easier to start and run better too.   The Jag was always a slow starter when cold – not anymore.

The post E-Type brake overhaul appeared first on Classic Jalopy.