2008 Mercedes GL320 – Air Suspension Repairs

2008 Mercedes GL320 – Air Suspension Repairs


Mark: Hi, it’s Mark from Top Local here with
Bernie Pawlik.
Pawlik Automotive in Vancouver.
Thirty eight years repairing and maintaining
cars in Vancouver.
Twenty one time, only 21 time winners of Best
Auto Repair in Vancouver as voted by their
customers.
And we’re talking cars.
How are you doing today, Bernie?
Bernie: Doing very well.
Mark: 2008 Mercedes GL320 had some problem
with the air suspension.
What was going on with this vehicle?
Bernie: Yeah, so the vehicle came to our shop
not sitting properly.
One corner of the vehicle was leaning down
too low.
Yeah, so that’s basically the client’s complaint.
The suspension system just wasn’t levelling
itself out properly.
Mark: So how do you test to find out the cause
of this?
Bernie: Well, first of course, a visual inspection.
Then there’s a couple of buttons on the dash
you can press to raise and lower the vehicle.
That wasn’t working.
Next step, a scan tool.
A good quality diagnostic scan tool.
We found a couple of codes in the system with
low system pressure, and then we performed
some diagnostic tests.
The scan tool we have is awesome.
You can run a number of tests where you can
set the level of each air spring.
You can test the pressures in different parts
of the system.
And what we found is basically the pressure
was very low, and nothing we did would would
operate.
As the test went by we found the compressor
basically was not operative and it basically
died.
Mark: So, is the compressor the only part
that you replaced?
Bernie: No, we also replaced the … There’s
a solenoid valve pack located right above
the compressor.
We’ll get into some pictures in a minute,
but that’s also a common failure item on this
vehicle.
It was original, like the compressor was,
and so it was a good time to replace that
piece.
And not a lot of extra labor involved with
the compressor out and it just made a lot
of sense.
It’s good to do these things.
Often when parts are located nearby each other,
there are sort of common failure items to
replace them in partnership.
It makes for the repair bill a little higher,
but then the customer’s not going to be coming
back in a month or two or six months or maybe
even a year going, “Oh, this side’s not opening
or closing.
This spring’s sitting too low,” because this
part’s failed now.
Then you’ve got to pull everything apart again
and change the other piece.
So, it kind of makes for a more thorough,
satisfying repair.
Mark: And adds longevity.
So did you find any other issues when performing
these repairs?
Bernie: Yeah, we did.
And what I’ll do, let’s just get into a quick
picture share and then I’ll talk about some
other issues.
There’s our full size GL320.
This is a diesel.
Again, yeah the full size, the ML’s similar
but a shorter, slightly smaller version.
So this is a Mercedes full size SUV.
And, other pictures.
So let’s have a look.
This is the compressor.
This is with the right fender liner removed,
so the wheel would be sitting right here.
There’s a big plastic fender liner comes out,
and there’s the air suspension compressor
located right in this area here.
The a solenoid valve pack that I mentioned
is located right up here.
We’ll just get into a little more of a closeup
picture of this piece.
This is the compressor, sort of viewed side
on.
This is the air inlet hose where the air is
sucked into the compressor.
So the red arrow indicates the compressor
unit, which it goes back in, it’s a fairly
large piece, goes back in a little ways.
And then the a solenoid valve pack sits up
here.
Basically, this is the main airline from the
compressor and then it has five other lines
that go off to various other areas on the
vehicle.
Four to the air springs, and one goes elsewhere,
which is probably a vent line or possibly
an air reservoir.
Anyways, six lines on that piece.
Now what else have we got here?
Yeah, so what else did we find?
This is the main power connector to the compressor.
This runs the compressor motor, and as you
can see, it looks a little ugly.
When I removed this, there’s two electrical
connectors.
One of them which operates a solenoid, popped
off right away.
This one here required a bit of a hammer to
bang it off and it was pretty evident as to
why the connector was stuck.
It basically had overheated in this plastic
and melted.
And why it overheated, this adds another issue
that needed to be repaired.
Fortunately, Mercedes has repair wires and
a nice connector plug in stock, so we can
actually take these wires, cut them, solder
them, put proper heat shrink covering on it,
and it’s got proper weather packs and a nice
connector and everything fits well, and it’s
going to ensure the right connection to the
compressor.
So, that was the other additional repair we
found, that this wiring plug had overheated.
Mark: So once you replace all this stuff,
is it just turn the car on and everything
works, or is there something else that you
need to do?
Bernie: Well, you’d think it would because
it’s all computerized and it has ride height
sensors and pressure sensors, and it would
go, “Okay, there’s not enough pressure in
the system.
Let’s pump that up and let’s raise and lower
the height of the vehicle,” but it doesn’t
seem to work that way.
It seems to require a bit of finessing to
get it going.
So I had to basically manually power up the
compressor to build up the pressure, and then
from there, on our scan tool there’s some
height adjustments you can do to adjust the
height level of the vehicle.
And so that’s a bit of an involved procedure,
but once we did that then the vehicle sat
properly and the whole system came back to
life.
Mark: So, why did this compress your die?
Is it just old age?
This is an 11 year old vehicle.
Bernie: Well, old age is part of it.
They only have a limited life span, and 11
years is a pretty good run for one of these
parts.
But the other thing, a bit of history on this
vehicle, a couple of months ago the owner
had some issues with the suspension system
and we found the two front air struts were
leaking air.
The right rear also had a leak or there was
something going on with the right rear.
I believe the left rear had been previously
replaced.
So we replaced three of the four air struts.
So that, of course, taxes the system.
This system runs very hot, as you can see,
those wires that were melted.
There’s a lot of current.
This system is fused with a 40 amp fuse, which
is pretty large.
And in my process of filling the air suspension
compressor I put in a test relay, which basically
bypasses the system and allows me just to
power up the compressor.
And after running it for about three minutes,
I pulled the relay out and it was so hot I
could barely touch the connector pins.
So there’s a lot of heat generated, a lot
of current flow, and so if you run the compressor
a little too long it’ll shorten the lifespan
for sure.
So had these air struts not leaked, chances
are the compressor may have lasted longer.
But this is also one of the higher failure
items on any air suspension system.
The compressor, it works hard.
It’s not always on, but several times a day
or during a drive it’ll be on to adjust the
suspension system.
Mark: So just so we’re clear about it, when
the air is leaking out of the air struts,
the compressor has to run to try and replace
that air that’s leaking out so it’s running
a lot more.
Bernie: Exactly.
Exactly.
And what’ll happen too is, there are timers
in different vehicles, they have timers on
the compressor or temperature sensors on some
of them.
So, if the temperature exceeds a certain amount
in the compressor or runs for a certain amount
of time, it’ll just time it out.
And this is when you start noticing how the
car is not … It won’t level out properly
because the compressor will run for a while,
then it just shuts off and then it has to
cool down and it’ll run for a while longer.
So there are built in features to prevent
them from overheating and burning out, because
that will happen if you have a bad leak.
It’ll just keep running and it’d fry the compressor,
and who knows what other wiring issues will
happen, too?
Mark: So, is there anything that an owner
of an air suspension vehicle can do to lengthen
the life of the compressor?
Bernie: Well there isn’t really, other than
if you happen to notice the vehicle’s sitting
funny, certainly get it diagnosed and fixed
right away because that’ll probably be causing
the compressor to run too frequently.
And so, the faster you can repair it, the
longer your life of your compressor will be.
So, that would really be the only thing I’d
advise.
Other than that, I mean, it’s a self contained
sealed system.
There’s no filters to change or anything else
to do it.
It really kind of runs itself, and the components
will last as long as they do.
10 to 15 years is kind of what you’re going
to get out of an air suspension spring, so
if you own an older one you can kind of count
on they’re all going to need to be replaced
if it’s 10 years old or older.
They’re all living on borrowed time.
They are expensive, but an air suspension
is awesome because you do have control over
the height of the vehicle.
You can raise and lower it in most cases for
better ground clearance, or drop it down for
better handling.
If you pack it full of people and cargo, the
car rides nice.
But it all does come at a price.
Mark: So just to go back into this leak, how
would you know that there’s a leak in your
air suspension?
You come out and the car’s sitting funny,
or it’s lowered?
Bernie: Exactly.
You’ll come out in the car sitting funny.
That’s the kind of thing where you come out
in the morning, maybe you park your car at
night, you come out in the morning and maybe
the left front corner of the car is sitting
too low or the right rear, or whatever it
is.
One corner of the car will be sitting too
low, or you might-
Mark: Or all of them.
Bernie: Or all of them, yeah.
If they’re all down, that’s an issue, too.
You know, it’s interesting.
We actually have another Mercedes of this
exact type in the shop right now, and the
owner complained some issue with the air suspension.
We looked at, it seemed to be fine.
It needed some other work, so we did some
other work on the vehicle.
Brakes and a couple of other services.
Put the vehicle back on the ground, drove
out and the front air springs junk sunk.
So they had tiny little leaks that weren’t
really apparent, but then after looking at
it, okay the left front struts leaking.
Of course now both of the front ones dive.
So it needs air struts on that vehicle, too.
So if you notice anything that’s sitting off,
right away, that’s the time to get it in for
repairs.
Unfortunately you go, “Oh yeah, it’s going
to cost money.”
It will, but it’s better to do it sooner than
later.
Mark: Yeah.
It’s going to cost money right away, but if
you leave it, it’s going to cost a heck of
a lot more because now you’re replacing the
compressor.
Bernie: Yeah, exactly.
And the thing is, it may be that inevitably
the compressor’s going to go anyway because
if it’s original, it’s never been replaced,
and the vehicle’s again, 10, 12 years old,
the compressor’s probably not got a lot of
life left in it anyways.
But fix it as fast as you can.
That’s the key with any vehicle.
You fix what’s broken, or any noticeable issue,
fix that first and that’ll save you money
in the long term.
Mark: So there you go.
If you’re looking for service for your Mercedes
or air suspension vehicle in Vancouver, the
guys to see are Pawlik Automotive.
You can reach them at (604) 327-7112 to book.
You have to call and book ahead, they’re always
busy.
The website, pawlikautomotive.com.
640 plus articles and videos on there for
your viewing pleasure.
Dig in.
There’s tons of information on repairs and
maintenance of all makes and models of cars.
How to prepare your car for winter, et cetera.
Of course, Pawlik Auto Repair is our YouTube
channel where we have, again, quite a few
hundred videos talking about all makes and
models of cars.
Thanks so much for listening to the podcast
and watching.
We appreciate it.
Thanks, Bernie.
Bernie: Thanks, Mark.
Thanks for watching.

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