Changing Radiators

[hobdayd]

Hi,

 

I brought my Cayman 3.4S 2006 49,000 miles knowing condensers / rads might need doing.

 

I had some marks on the front bumper so removed it a few days ago to be resprayed. Whilst the bumper was off I decided to replace the air con condenser rads. They had some damage and oil discoloration. This is an easy job with the bumper off.

 

Now I have decided that whilst doing the condenser rads I might as well replace the original cooling radiators as there are some crusty lumps below where the AC condensers covered. These lumps might be bugs etc. that don't brush out but they seem embedded in the matrix and I suspect radiator damage. I am taking the car to Italy in June so want the cooling system to be at its best.

 

My question whilst waiting for parts...can I remove the radiators from the fan housing whilst the fan housing is still bolted to the car? Or do I have to remove the whole housing to access radiator retaining clips / bolts. (Not clear from google)!

 

Another question...can I use hose clamps to limit the amount of coolant loss then once reassembled inject coolant into the new rads via the breather hole prior to fitting the breather pipe and releasing the hose clamps?

 

Got to say that for a 12 year old car there is no rust / corrosion visible up the front end. Very happy. I could not say the same for my previous XKR!

[hobdayd]

Ok, no replies so had to find my own way...just finished changing the radiators and thought I would give you an update.

 

Taking the rads off is quite simple...I brought Sealy VS032 radiator hose clamps and placed them mid way on the hoses running into the quick hose connector fitting attached to the back of the fan housing. I then pulled the hoses out of the quick coupler at the fan housing.

 

I did one side at a time.

 

The RH rad / fan assembly was a little more difficult because there is a wiring connector block bolted to the assembly. To remove this one I removed all bolts / clips holding the rad to the fan and the fan to the car. As you pull the parts apart the radiator separated from the fan mount leaving the fan and steel frame loosely attached to the car.

 

The LH rad / fan assembly comes out whole making this slightly easier than the RH side.

 

I managed to capture 95% of the coolant during disassembly. After fitting the new rads and reconnecting the hoses to the quick coupler (with the hose clamps still in place) I used a syringe to put back in most is the coolant that came out from each side by injecting the coolant into the breather hose opening.

 

After doing both sides I have about 0.8 litres of coolant that I could not get back into the system. When the rad was as full as possible I refitted the breather hose and removed the hose clamps. 

 

I did not change hoses but I was careful when transferring the hoses to the new radiators to ensure the clips fitted in exactly the same place.

 

Waiting for the air con condensers to arrive and get my resprayed bumper back. 

 

 

 

 

[Bushman]

sounds like a good job well done Hobdayd

[Woodhouse]

Hobdayd, it can be a bit tricky getting the cooling system fully refilled with no air trapped.  In the engine compartment there is a bleed valve on the right hand side.  After filling the system to the max mark, this needs to be opened and the car run for a while.  I left the valve open for several journeys, keeping a close eye on the coolant level and topping up as required, before mine settled down.  

 

As for changing the hoses, I'd be very surprised if the ones that connect to the aluminium coolant pipes that run across the car near the steering rack could be separated from the pipes without damage to the pipes.  These connections seize due to corrosion.  Unfortunately sooner or later they will start leaking and replacement of hoses and pipes will be required.  Often these are the source of slow coolant loss that can be difficult to track down until the leak rate becomes obvious.

[hobdayd]

Both bottom hose metal inserts showed some minimal surface corrosion but only on the air side of the "O" ring seal. The seal grooves were not corroded and O" rings were OK but you are correct Woidhouse...it us only a matter of time and I will now keep an eye on them.

 

That is one if the benefits if doing the work yourself if you can - you get to know the areas to keep an eye on.

 

Thanks for the reply.