Brakes and Air Suspension

Since the engine is actually running, a few things needed immediate attention.  Brakes and air suspension.  There are no brakes since I removed the calipers, and a rear air bag is leaking bad enough that the car has trouble coming up with the engine running.

So, for the brakes, the process was fairly straightforward:  replace everything!  The car received new master cylinder, rotors, pads, hoses, and hardware.  Along with rebuilt calipers and a few new hard brake lines that wouldn’t come apart.

I didn’t take too many pictures as the work was quite routine.  I also repacked the wheel bearings with new grease, the bearings were in nice shape.

Now, to the interesting part:  air suspension.  I ordered up front and rear bags, along with all the necessary o-rings.  The o-rings are somewhat special, they’re square, and they’re expensive!  Not all of the o-rings came in, so I worked only on the rear bags.  Replacing them took me the better part of a whole day.  Removing the assemblies that hold bags required removal of the back seat, along with the front mount of the passenger side trailing arm to clear the exhaust.  Once they were out, it was clear just how beat up they were.

The air cells and hardware the holds the bags in looked pretty bad, but with some soaking, everything came apart.  A good PH3 philips head screw driver was very helpful here.  Once inside, the mating surfaces for the rubber looked surprisingly good and only needed a bit of cleaning:

Once put back together, I was able to fit a schrader valve and test for leaks.   I’d be surprised if the mating surface could leak.  The design is very good here.  Heres a bag filled with about 50psi of air.

Since I consider replacing of these parts just part of basic maintenance and repairs, not restoration work, I didn’t do much else to clean up the appearance of the parts.  I was happy with the clean interior of each of the air cells, and the fact that they don’t leak!

With everything back together, a short drive was possible!  Heres the car backing out of the garage for the first time.

And, outside, sitting at a nice ride height:

I drove around the parking lot several times.  I was quite happy to feel all four gears of the transmission, feel the power steering and brakes, and check the basic functions of the car.  The engine ran, but its clear that it needs a lot of fine tuning to run well.  It seems to be very rich and doesn’t idle well.    More work for the next days!




W109 Brakes

With the sale of the 300SDL, I’m motivated to start doing some serious work on the 300SEL.  Once the engine is running, the following things need to be done at nearly the same time in order to actual drive the car a bit:

  • Brakes (replace everything)
  • Suspension (new air bags in the rear, at the very least)
  • Tires (nice ones)
This is a short, but fairly expensive and time consuming list.  In order to get a bit ahead, I decided to pull off the calipers and send them off to be rebuilt.  I was happy to find everything came apart nicely.  The wheel bolts weren’t too tight and nothing was very rusty.  This further supports the low mileage of the car, and an easy life.  After about two hours, I ended up with this collection of parts:

It was nice to see the brake pads were original Mercedes parts.  The star was still visible on one of the rear pads.  I suppose the aftermarket parts business was non-existant in the 1970s and 80s, or these were installed at the dealer.  It was also worth noting that the brake hoses were marked with “Ate”, but had nothing else visible.  This makes me wonder if they’re original.  The hard brake lines broke free from the hoses and calipers up front easily, but things were not so eager to come apart in the rear.  I removed the calipers, but both ends of the brake hoses look as if they’re not willing to come free from the lines.  These lines are pretty short, so getting replacements won’t be such a big deal.
Once the calipers get back from the rebuilder, I’ll order up a new master cylinder, pads, rotors, hoses, hardware, and any hard lines I may need.  I don’t want to take any chances with the brakes, so replacing everything is the way to go.