Removing Auxiliary Radiator in a 90Q

[Richard Beels]

Here's a note for the archives - or the wiki if someone wants to put it in 
there...


How To Remove The Auxiliary Radiator in a 90Q
=====================================

- Remove the plastic piece covering the main & A/C radiators.
- Remove the front grill (4 phillips-head screws).
- Remove the bolt holding the main radiator support arm to the front 
support (8 mm).
- Remove the bolt holding the plastic radiator shroud to the front support 
(6 mm).
- Remove the front bumper: slide the 2 covers out of way; remove the 2 hex 
bolts; gently pop the side covers off; slide the bumper forward being 
careful not to rip the foglight wires off; using a small screwdriver, 
gently pry/pop the foglight wires off.
- Remove the bumper/grill trim piece (2 x 10mm) and pop it off at the sides.
- Slip/pop the hood opening wire from the three plastic clips in the front 
support.
- Remove the front support (4 x 10mm on top, another 10mm on the bottom).
- Get a hose clamp and clamp the "triple" hose (thermostat/bottom port on 
aux rad & bottom of main rad) between the union and the aux rad.
- Loosen the clamps holding the hoses on the aux rad.
- Remove the aux rad by removing the 2 x 10mm nuts holding it on at the 
bottom.  You'll need an extension on the ratchet and do it by feel.  If the 
nuts get stripped, you can sawzall/hacksaw/dremel off the rad by going 
through the rubber isolation bushings.
- Get a large bowl to catch the coolant dumping out of the aux rad.
- Remove the top host from the rad first so you can better control the 
angle once the lower hose is removed and coolant starts flowing.
- If you didn't clamp the triple hose well enough, you'll start losing 
coolant from the whole system at this point.

At this point, you have options as to how you're going to plug the 
hoses.  Plugging the hoses is preferred to connecting them together because 
connecting them together would allow hot coolant to bypass the main 
radiator and this would (further) decrease system cooling efficiency.  Not 
only do you want to plug the hoses but you need to affix them in place so 
they don't flop around and come into contact with something else in the 
engine bay, say, the alternator.

What I did was make a combo plug/holder for the hose ends out of 3/4 copper 
pipe and a couple elbows and end caps.  It's hard to describe but it goes 
like this: end cap - 4" piece - elbow - 7" piece - elbow - 4" piece - end 
cap, all in the same plane.  In cheesy ascii art, it looks like this:

|= is an elbow, = is an end cap, dashes and pipes are plain tubing.

   |=  ---- =     (hose from MainRadTop)

   |
   |
   |

   |=  ---- =     (hose from MainRadBottom/Thermostat)

The ID of the coolant hoses is the perfect size for a 3/4" endcap.  You 
don't need to make plumbing quality joints because the endcaps are plugging 
the hoses and are watertight in and of themselves.  You might want to drill 
a pressure-relief hole in the 7" piece to make the final soldering easier.

Once you have the piece solder and have dumped it in the drained coolant to 
cool off, put it into the hose ends and push it past the end swells so that 
the caps are seated in "virgin" hose.  Tighten the hose clamps past the end 
cap and around the regular tubing to give a mechanical lock to the setup.

Last step is to grab a drill and drill a couple holes in the plastic shroud 
on each side of the hose and zip-tie the hose to the shroud so more firmly 
anchor it into place.

And, as Mr. Bentley says, assembly is the reverse of removal.

Took me a couple hours to do last night with lots of time wasted trying to 
repair the aux rad.  One section has a pinhole so I cut it out and got the 
ends brazed but then another section blew out with only waterhose pressure 
so the aux rad was officially pronounced dead and binned.

Cheers!