R129 A/C condenser replacement

[DrNick]

The condenser on my 99 500SL is cracked so needs replacing.
Does anyone have any top tips for doing this (other than getting a mech to do it). It looks relatively straightforward to me but there may be traps waiting such as specialist tools and I don't want to get halfway through to discover this.

Are there a myriad of different part variations, and how easy is it to replace the drier? Where's a good place to get the parts?

It will go to a local place to be pressure tested and refilled afterwards but I think I can save the labour charges on actually changing it and it looks interesting!

Any advice appreciated.

 

[alabbasi]

Get new o-rings and PAG oil to lubricate the o-rings before installing. All the lines and fittings are made from aluminum which is soft so be careful to not twist any of the lines.

 

[Ted]

I would recommend a new receiver/drier any time the system is depressurised.

 

[Stratman]

If it's anything like my '04 W302 (so younger than yours) be aware the pipes into and out of the condenser may be corroded (dissimilar metals) and might be almost welded in. In the extreme you may need to cut them off and replace the pipes.

 

[BlackC55]

Be very careful with the AC pipes. They are aluminum and tend to pull the threads when undone. Gently warm the union that turns and cool the fixed pipe with freezing spray and they should undo.

 

[WilliamParsons]

Be cautious with aluminum AC pipes; use temperature methods to prevent thread damage during removal.

 

[DrNick]

Be cautious with aluminum AC pipes; use temperature methods to prevent thread damage during removal.

Great advice everyone. I'll proceed with caution. Does anyone know if I have to get the bumper off to do it. It looks like on the 320 you don't have to, but I haven't found anything about the 500. I've seen reports that on the R230 there is a steering fluid pipe that needs disconnecting. Is that necessary on the R129?

 

[Doodle]

It's been at least 10 years since I changed the rad on my 500, so this is from slightly dim memory. The condenser and radiator form a quasi-cassette pack that drops in from the top. The radiator has dowels on the bottom panel that sit into a couple of rubber-bushed recesses, and is clipped at the top. Those same clips fasten the condenser as a sandwich, and the bottom of the condenser hooks onto locating points on the lower edge of the radiator.

To get it out, I unclipped the top and then unbolted the slam panel for access. Because I was only changing the rad, I left the condenser in situ and wiggled the rad off the back of it - you will probably just want to take both out at once. There's a trans cooler line that runs along the bottom edge and up one side - this WILL be crusty and may well die when you try to unbolt it so you will want to change that at the same time, it's not expensive. You should need to touch the oil cooler that sits in front of all of this in the lower bumper.

 

[WilliamParsons]

To replace the radiator and condenser in your car, unclip the top, unbolt the slam panel for access, and wiggle the radiator off the back of the condenser. Be prepared to replace the crusty transmission cooler line. You likely won't need to touch the oil cooler in the lower bumper.