DSC and flat tyres.

[101RRS]

Driving back to Canberra yesterday I was on a secondary road and had to negotiate a tight right hand bend over a small bridge. I was doing less than 50kph and at the apex of the bend the DSC violently kicked in - at no stage prior do the DSC activating did anything feel odd in the car - no sliding, lurching - nothing at all.

I thought that was odd - initially thought that the weight of the trailer had pushed the car a bit sideways but I had not felt anything and as we were about to stop for lunch I decided to check things then. As I pulled up I remembered that odd DSC activations could be a flat tyre.

On checking the tyres I found the rear passenger tyre was all but flat.

The DCS had detected the slight sideways movement (that I could not detect) when I was turning right.

This was the first time I had to change a tyre in anger and the jack is a real worry - the car farted and it nearly fell off the jack so a better jack will be sought. Also I knew that a door should have been open but forgot about it and all doors were closed so allowing the suspension to adjust.

The other trick for new players (even though I knew about this) is not to put the jack in the hole in the air compressor cover. I have jacked the car a few times in the drive way and always got the jack in the right hole in the chassis, but for some reason I put it in the hole in the air compressor cover - it actually lifted the car and it was not until there were some cracking noises coming from under the car that I realised something was wrong and moved the jack to the correct position. The pump still pumps the car up but where I have never heard the pump run before it is now quite loud - maybe because the cracking sounds were the cover breaking and letting the sound out.

So some lessons - if DSC activates unexpectedly, check to see if you have any tyres are going down.

When you jack, make sure it is in the chassis holes and not the air compressor cover hole (it is the right size)

Be very suspect of the safety of the jack - make sure a door is open to prevent suspension adjustments (farts).

Garry

[camel_landy]

The easy way is to just leave the tailgate open - which you need to open anyway to get the spare & jack. ;)

M

[Graeme]

Hopefully you haven't broken the compressor mounting bracket.

Did you put the vehicle in off-road height before starting to jack?

[101RRS]

The easy way is to just leave the tailgate open - which you need to open anyway to get the spare & jack. ;)

M

The doors were closed but the full tailgate was open and it still readjusted itself.

Garry

[101RRS]

Hopefully you haven't broken the compressor mounting bracket.

Did you put the vehicle in off-road height before starting to jack?

Knowing how much you have to jack the sucker up to get the wheel off the ground I had it in at offroad height and LLAMS at +50 (hey another use for LLAMS). The pump is still working OK so hopefully it is only the outer cover that has cracked - I will check it later this week when I get the tyre repaired.

Garry

[Graeme]

Ha Ha, it crossed my mind that perhaps getting max height might be even better!

[kenl]

If it's the rear wheel I know for sure (from experience) that when you jack from under the wishbone going to the tyre, that the wheel will lift it's self off the ground as soon as the jack takes the weight. Don't know if this works with the fronts though, and all doors were closed, car unlocked and key in my pocket. (jacking the car)

[Dingmark Jim]

After a somewhat similar jacking "near miss" (my daughter started jacking the compressor hole) on my old D3, I have painted both the 4 correct holes and the top of the jack red. That way even at night the jack will hopefully go in the correct hole.

[bbyer]

If it's the rear wheel I know for sure (from experience) that when you jack from under the wishbone going to the tyre, that the wheel will lift it's self off the ground as soon as the jack takes the weight. Don't know if this works with the fronts though, and all doors were closed, car unlocked and key in my pocket. (jacking the car) I regard jacking the rear wishbone as difficult relative to the front. There is a little dimple on the underside of the front wishbone in just the right place for a small bottle jack, (2 ton), to fit. It is like it was planned; the dimple in the underside of the rear wishbone is not so ideally placed but does work OK as well, but it is not as elegant a technique. It kind of sounds like a compressor case should be on both rear sides to jack on.:D

My field procedure is one six ton bottle jack or the LR scissor jack placed under the frame near the troublesome tyre and lifted just enough to take some of the vehicle weight. The baby bottle jack is then centered under the dimple of the appropriate wishbone.

I only lift the rubber about a 1/4" above the road surface - well more as the tyre is low, but such that I hardly have to lift the replacement tyre any amount. The technique is relatively safe as the car is barely lifted.

Also my experiences seem to suggest that leaving a door or tailgate open does not cancel the auto self levelling program. It seems to have mind of its own and can come into play anytime. About the only thing that truly shuts it down is disconnecting the battery.

Whether one uses one jack or two, the wishbone lifting procedure has much merit as the car body is not raised very much and hence the vehicle is barely out of level.

[Redback]

I just bought the D3 coil 2 stage jack for our D4, that sizzor jack is useless and the car adjusting is a pain, and yes I had the doors open, what I didn't do was set it to offroad height:mad:

If you use the jacking point for the D3 S coil model, it jacks the wheel off the ground no problem;)

Baz.

[Geedublya]

what I didn't do was set it to offroad height:mad:
Baz.

Didn't you learn from my experience Baz?

Got a part number for the D3S jack?

[gghaggis]

Gary,

If you need a replacement compressor mount (it usually breaks when the compressor is hit) I've got a 2nd hand one for sale.

Cheers,

Gordon

[gps-au]

Hi Folks,

After reading this thread, I am more than convinced I made the right decision to carry an air/exhaust bag for lifting. The original jack has never been used since a trial run when the vehicle was new (& I never liked it).

I found the exhaust system and plugging really is dirty work, so nowadays just use the portable compressor and bag, plenty of lift, so it does dual duty when/if required.

As to the main topic, This I made a simple mistake the other day of NOT investigating why the DSC kicked in, then remembered this thread, yup, nail in the left rear, a quick pull, plug and refill and away we went, didn't even have to lift the vehicle apart from move to offroad for a bit of extra clearance.

It was down to 5 psi so probably just saved the tyre.

[101RRS]

Hi Folks,

After reading this thread, I am more than convinced I made the right decision to carry an air/exhaust bag for lifting. The original jack has never been used since a trial run when the vehicle was new (& I never liked it).



I would never use a air/exhaust jack for changing a wheel - they are just too dangerous and can fail at any time. They are OK for their use as designed ie helping when bogged but never for changing a wheel.

Garry

[oldsalt]

I would never use a air/exhaust jack for changing a wheel - they are just too dangerous and can fail at any time. They are OK for their use as designed ie helping when bogged but never for changing a wheel.

Garry

I think this statement holds true for the LR jack too ... unfortunately :(

[scarry]

I think this statement holds true for the LR jack too ... unfortunately :(

Ok,so who knows of a good replacement jack.

Ridiculous really,a 20K Mitsy express has a better jack,but it probably is not rated to lift the weight of a loaded D3/4.

[101RRS]

I finally got around to taking the covers off the air compressor today and as expected the compressor mount has cracked - in fact it is in about 10 pieces.

I am actually surprised how weak the brackets are given the thickness of metal a how it is bolted to the chassis - crap alloy I guess. The full weight of that corner of the car did not get onto the mount - maybe 500kg of static load and I would have that the mount should have carried that.

Despite an large number of creek crossings and very dusty conditions the compressor looked like new - though I am surprised at the amount of padding in the covers - no wonder the compressor gets hot at times.

I would have thought that a fitting that allows airflow and easy cleaning would have been better.

Thanks to Gordon for a replacement bracket.

Cheers

Garry

[101RRS]

I can now see why there is so much padding around the air compressor - mine is now held up with a rachet strap without the covers on - you can hear it running from 50m away and I didn't realise it runs so much -runs more than it is off - constantly filling the tank as the suspension readjusts itself to different drivinhg conditions - little wonder it wears out.

Initially I found two holes in the rear tyre and had these fixed - they were very small holes that looked like nail holes but there was no foreign body there. I had these repaired but the tyre was still loosing air - going over the tyre with the spray bottle I found another two holes - the same as the first two - very small. All fixed now and holding air - I must have run over sonme wood with nails sticking out. All other tyres are OK.

Of note was that all the holes were in the tread area but not through the tread block. All between the tread blocks where the carcass is thinest.

Garry

[Graeme]

I am actually surprised how weak the brackets are given the thickness of metal a how it is bolted to the chassis - crap alloy I guess. The full weight of that corner of the car did not get onto the mount - maybe 500kg of static load and I would have that the mount should have carried that.
I'm happy that the bracket only weighs enough to support the compressor as the vehicles are already heavy enough. I wouldn't like to suspend 20kg from it but it holds the compressor quite successfully.

[gghaggis]

I'm happy that the bracket only weighs enough to support the compressor as the vehicles are already heavy enough. I wouldn't like to suspend 20kg from it but it holds the compressor quite successfully.

They're strong and lightweight, but extremely brittle.

Cheers,

Gordon