Airconditioner Odyssey

[WGB]

As you may be aware I think I have found my leak - a porous corroded area on the suction side of the compressor manifold. On a 6.9 this is secreted on the right side of the motor beneath the battery tray and above the hydraulic lines for the dry sump.

Here is a photo of the compressor in-situ with the battery and tray removed and the compressor still attached to both it's mountings and it's manifold.



Here is a photo of the manifold in roughly the position it sits in the car after a somewhat difficult removal process which included removing the compressor as well. Fortunately I had asked for my old compressor back when this new one was fitted and it had a blanking plate attached which I was able to transfer to my good one while I wait for repairs.



Here is the same manifold turned upside down and showing the corroded area.



I have just dropped this off to an Engineer friend who is going to repair it permanently (hopefully).

Bill

 

[Styria]

Hi WGB,

In my opinion, removal of the compressor is one of the worst jobs on a 6.9, and replacement is even more taxing because the unit is so heavy to put and hold in place. If I remember correctly, one of the bolts to the back of compressor/bracket has to be fed in 'blind' and caused no end of frustration.

How long do you think you'd allow for R&R from go to whoa ? I hope the system is going to work well for you once the repaired pipe is installed. Regards Styria

 

[WGB]

Fortunately my car is on my hoist and it is easy to go from under bonnet to under car and back again.

The blind bolt at the rear is quite visible from underneath so I hope it is easier to get back in than you suggest.

It took me about two hours to get the pipework and compressor out from go to whoa.

Bill

 

[Styria]

In my opinion, Bill, that is excellent work - the time factor is almost unbelievable. Having the hoist must make all the difference. Regards, Styria

 

[WGB]

Styria - I shall take that as a compliment but it had only recently been installed so all bolts and connections were easy to undo.

The hoist makes an immense difference to both time and personal ease and was given to me a couple of years ago by a friend and neighbour who was updating his commercialworkshop.

We are not getting any younger and grovelling on cold concrete hurts these days.

Bill

 

[Michel]

Amazing find Brother Bill,

I certainly agree with you on the practicality of having a hoist....

Priceless....

 

[s class]

I can sympathise with the removal of the A/C compressor, as I did this the other day on trusty rusty as part of the sump removal process. I was not surprised to find, given the standard of workmanship this car was subjected to during the PO's curatorship, that the rear bolts had simply been omitted. I ended up removing the mounting bracket with the compressor.

I did not specifically time how long it took to remove the comressor, but from the time I crawled under the car till the sump was off, was about 4 and a half hours, including compressor removal. THis does not include disconnecting the 3 fat lines from the oil tank and removing the radiator as that had been done earlier.

All in all, the removal of the sump is a thoroughly unpleasant job.

 

[WGB]

I replaced my compressor today.

In a nutshell I found it it easier to remove than replace.

My Engineer friend cleaned the corroded area of the manifold and braze coated it.

With the end sealed I applied vacuum to it and could not find a leak so painted the area and covered it with insulation as it is supposed to have.

With the battery and tray, alternator and it's mount removed it is actually quite easy to drop the whole compressor and manifold as a complete unit back down the hole and the two front bolts present no real challenge.

What does present a challenge is getting the rear mounting bolt with it's spacer (my car has a spacer between the rear of the mount and the back of the compressor, like a thick washer) in position and started on the thread. It is easily visible with the car in the air by standing in the wheel arch and looking up the back of the dry sump piping.

The compressor is heavy and hard to get centralised in the limited space.
The bolt wouldn't start in the compressor mount until I removed the metal plate that guards the hydraulic lines to give a bit more access and tapered the end of the non-standard bolt (and cleaned up the thread). It then went in first time.

Obviously easier to put back in before the hydraulic lines S-class.

Just some observations.

Bill

 

[s class]

Well done Bill. I'm sure this has left you with a sense of accomplishment - and sore arms.

 

[Styria]

Great work, Bill and thanks for the detailed procedure in R&R of the compressor. I am sure that there is at least one other member that would have followed your progress with a certain amount of interest !

I also found the re-fitting of that rear bolt the most difficult on account of the washer, plus the fact that the compressor is so heavy to hold in place and it is awkward getting your hand in with the washer centralized, holding the compressor steady and get the bolt started. I would imagine that you would have been able to support the compressor with your gearbox hoist - that would have considerably eased the job and prevented you from getting sore arms like S-Class and myself have found. Regards, Styria

 

[WGB]

Picked up my 6.9 today with working Air-con.

The air-con shop pressure tested it by filling it with pressurised Nitrogen and leaving it for nearly 48 hours.

Emptied the nitrogen and re-filled with 134.

I replaced the receiver-drier with a new one from AutohausAZ after several attempts to get one locally. The EPC and the local suppliers list the 450 one which in RHD form is a mirror image of the 6.9 one and fits on the opposite side. Fortunately the US models including the 6.9 all seem to have it on the left side and all for less than $20.

Hope that it's now fixed for good.

Bill