andrewsofiakis

I noticed my '03 S600 started leaving little puddles of coolant under the driver's side front bumper. Sometimes it was barely there at all and other times it was a 1 foot radius stain. I was filling my coolant reservoir about .5 gallons of coolant every 250 miles.

After getting under the car I was able to see that it was leaking from the notorious upper radiator hose connection at the connector with the metal clip.

Before ordering parts I decided to pull off the hose and see if I could get a look at exactly what needed to be replaced figuring it was either the connector on the hose itself, the seal that goes in the connector, or the male radiator spout. After pulling off the hose I inspected everything pretty thoroughly and nothing seems to be worn out, cracked, or unusual in any way.

So I ordered the o-ring seal that goes inside the upper radiator hose. It should be in tomorrow. I'm going to install that and reinstall everything else, then fill it up with coolant and see if the problem is still occurring. If not, I'll try replacing the whole hose.

I'll post some pictures as I go along.

Also, I noticed some radiator hoses for sale online have a the extra hose coming off it and others don't. I do know mine does have the extra hose, but anyone know what's up with the ones without the extra part?

lganski

The hose that you speak of is the upper radiator hose. The small hose goes to the coolant tank on the right side.

andrewsofiakis

Update:
I replaced the rubber seal on the upper radiator hose, not to my surprise it did not solve the problem. It appears there's a hairline crack somewhere above that hose close to the pass-through area for the intake.

Next Step: Radiator Replacement
I've been searching around for a DIY on replacing the radiator and to my surprise I haven't been able to find one that gives me confidence is starting this project i.e. step by step with pictures or detailed video.

If anyone knows of one please direct me that way!

Also, I bought a workshop manual on disk, it should have all the repair work steps on it, but when I load it up it asks me for some sort of password. Anyone know about how to get past this so I can get to the content?

Welwynnick

OK, here goes. I did this last month, so its fresh in my memory, but I’m afraid I didn’t take any pictures.

Before doing anything, inspect the new radiator and make sure it’s to spec; this is really important.
Make sure the outside diameter of the hose receptacle is 41.0 to 41.5 mm.
Make sure you have threaded receptacles for the fan cowl, IC HE, IC pump, AC HE and AC pipe fittings.
When you remove the old radiator, some of those fittings may be rusted up – test them first, and figure out what you’re going to do.
There are rubber & plastic mouldings all around the radiator to control airflow, and they take time to remove & refit.
Establish whether your header tank fills to the RH header tank, or the bottom hose.
The new radiator may have a ¾” filler hose receptacle that may need to be blocked off – which can make fitting more difficult.

Get yourself some good lights, and get to work….

Lift the front end of the car onto stands and remove the top and bottom covers.
Loosen the header tank cap and drain the cooling system. This takes a while.
Remove the thermostat/top hose housing and disconnect all the hoses (expect spills).
Disconnect the electric fan.
Remove the small clips that hold the top of the fan cowl to the radiator flange.
Remove the two clips that hold the bottom of the fan cowl to the radiator flange.
Unscrew the secondary radiator pipe from the bottom of the cowl, noting where the screws went.
Undo the two transmission oil cooler pipes, catch a bit of oil, and cover the pipe ends.
Undo the two nuts at the top corners of the fan cowl.
Pull the fan assy up an inch, tilt it back and pull it out upwards (pushing the IC pipes out of the way).
From underneath, undo the IC pump and its bracket from the radiator.
Still underneath, remove the bolt that holds the aircon pipes bracket to the radiator.
Unbolt the top L&R of the aircon condenser from the radiator.
Unbolt the IC heat exchanger from the radiator, and support it.
Undo the plastic clamps that hold the top of the radiator.
Push the top of the radiator back and remove the bleed pipe.
Remove the plastic brackets that are clipped half-way up each side of the radiator.
Lift the radiator out.

Lifting the radiator out is unsurprisingly more difficult than it sounds, as it’s a tight fit width-wise between the chassis rails. The problem is that there are three steering and suspension oil coolant pipes that squeeze through an aperture alongside the radiator. The aperture is sealed-up with a triangular rubber grommet, which best pulled forwards out of the way of the radiator. The three pipes then need to be manipulated so they’re flat against the chassis rail, and give as much room for the radiator as possible.

Now is the time to replace the anti-freeze, the thermostat, the thermostat housing o-ring, the hose connector o-rings, and the hoses and aux drive belt if you feel like it.

Refitting is the reverse of removal, but:
Check that the top hose assy fits both radiator receptacles before fitting the radiator (ask me why).
Tape sheets of corrugated card to the front and rear facesof the new radiator, otherwise you’ll make a horrible mess during fitting.
Make sure the secondary radiator pipe doesn’t foul the fan, as the cowl doesn’t protect it.
Make sure the aircon condenser is in about the right position before you push the new radiator forwards into position.
Make sure all the small hoses and cables are tied away from the moving parts, like the ancillaries and the aux belt.
The cooling system bleeds itself, but only when the engine is fully warmed-up, and you need patience.

If you’re prepared, it should take about a day.

Good luck, Nick

lganski

When you disconnect the oil cooler/trans cooler check the threads on the radiator you are removing. If they are damaged then you may want to make sure the mating nut on the pipes are OK. You may have to replace them also. When you have steel against aluminum they tend to seize up. Use anti-seize compound on the threads. I almost lost a new radiator to that problem. Next time I take hose off of that it will need a new radiator.

andrewsofiakis

THANK YOU NICK!!! That's enough info to give me enough knowledge about the repair to get started! I'm currently searching for a good radiator, once it comes in I'll do the install and add photos to that great step-by-step.

Iganski, thanks for the tip! I'll be sure to check that connection and use anti-seize.