tonycosta1984

In an effort to stop coolant leaks I'm about to do an overhaul on my 1993 s4 cooling and hvac system. So far iv'e acquired the following parts:
Thermostat
thermostat housing
Temperature sender/sensor
heater core
heater valve
034 10 piece silicone coolant hose kit with hose clamps
meyle blower motor (not pictured)
2 gallons of genuine g13 coolant (not pictured)

My question is what am I missing? I'd like replace as much stuff as possible while I have all the coolant out and hoses off etc... Thanks Tony

GoHeels

Perhaps the after-run pump if yours is old. Nice find on the metal thermostat housing. quattroworld.com Forums: After-run Auxiliary Coolant Pump and Fan Switch and 324 Control Module Info Your heater core looks totally different the one I just installed in my '95. Mine was about ~$140 from the stealership and had plastic sides and pipes. Yours almost looks used and all metal. Perhaps its fine, just wondering. I do know you don't want to do it again anytime soon. There are great writeups for the heater core, including Dave's. Took me about 8 hours over the course of a weekend doing it for the first time. Wasn't too difficult and I took my time.

Also you might want to replace the plastic fitting... quattroworld.com Forums: Cooling system hose, sensor and hardware info. ...on the back of the engine for this metal version... tried to hide a few links in there that might help.

GoHeels

Also, this 'tee' pipe behind the engine gets brittle and breaks. If yours is old you might want to replace it. It's on the hose that goes to the heater core. It houses a temp sensor. I'll include a pic...

tonycosta1984

Yeah the heater core brand is Spectra premium... info here: More Information for SPECTRA PREMIUM / COOLING DEPOT 94652


I bought it from rock auto for $133. I was gonna go oem, but this had the metal ends which sold me. Thanks for the info on the plastic fitting and after run pump

tonycosta1984

Also these are the silicon hoses and clamps that come with the 10 piece kit from 034 motorsports.

102-3049 aux pump inlet
102-3050 aux pump outlet
102-3051 exp lwr
102-3052 exp rad side
102-3053 heater #1
102-3054 heater #2
102-3055 heater block
102-3056 rad lwr
102-3057 rad upper
102-3058 tstat inlet
H08-1000 clamp worm drive m8x16
H08-1002 clamp worm drive m16x25
H08-1003 clamp worm drive m20x32
H08-1004 clamp worm drive m25x40
P01-0002 poly tubing
P03-0000 thermal label

I am going to replace the 034 965 561c - after-run pump
4a0 819 497 - HVAC temperature sensor 'T' fitting
034 121 143e - coolant flange

what other hoses do I need to buy if I replace those 3 things?

GoHeels

I'm fairly sure the hoses associated with those 3 things are already included in your kit.

tonycosta1984

Okay I finally got the after-run pump, HVAC temperature sensor 'T' fitting, and coolant flange. to go along with:
Thermostat
thermostat housing
Temperature sender/sensor
heater core
heater valve
034 10 piece silicone coolant hose kit with hose clamps
meyle blower motor
2 gallons of genuine g13 coolant

I'm gonna start this week, but I was wondering in what order I should attempt to install all these parts. I was thinking start by flushing coolant, Then heater core/ blower motor, then hoses, etc...

GoHeels

Sounds good. Given the choice might as well keep old coolant away from the new heater core.
You could bypass the old heater core while you flush, then do the heater core and blower swap, then replace hoses and after-run pump, then hook it all up with new coolant/distilled water. It primes itself fairly easily. I wouldn't even mess with the bleeder valve if possible, it can be fragile.

UrS4boy

When you get to the heater core install, you might find this DIY I wrote handy:

http://12v.org/urs/C4UrSHeaterCoreRe...ntDIY_Rev1.pdf

tonycosta1984

I'm at the step where you put the two heater box halves back together and I'm completely stuck with the way in which one of the flaps is supposed to go in. Part number 4ao819319a
One end by one of the servo motors with a circle clip and one end into one of the white arms?! No clip on the white end? What am I missing?