98 vert; 55000 on the clock. Just bought the car and I'm starting on the maintance run through. I don't think the Dex cool has ever been changed. My thought is to replace all the hoses and the t-stat and flush the system. I just wonder if a flush with water is ok. I have no overheating problems at all and the coolant is cloudy. I have purchased all the molded hoses at the local FLAP but they don't carry the 3 heater hoses. It looks like 2 are molded and one is straight hose. Any suggestions? Bill C is currently shut down, I guess my next shot is the Dealer. Comments.................

 

Hi There;
This is from a post by one of our c5 experts Patches.
The 2003 Owner's Manual says every 60 months or 150,000 miles, whichever comes first but I'm sure most here so it more frequently. Here's the drain/fill procedure.


Draining and Filling Cooling System

Caution
With a pressurized cooling system, the coolant temperature in the radiator can be considerably higher than the boiling point of the solution at atmospheric pressure. Removal of the surge tank cap, while the cooling system is hot and under high pressure, causes the solution to boil instantaneously with explosive force. This will cause the solution to spew out over the engine, the fenders, and the person removing the cap. Serious bodily injury may result.

Important
If the procedure below is not followed a low or high coolant level condition and/or vehicle damage could result.

1) Park the vehicle on a level surface.
2) Remove the surge tank cap:
3)Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
4) Place a drain pan under the draincock.
5) Open the radiator draincock.
6) Allow the cooling system to drain completely.
7) Inspect the engine coolant for the following:
Discolored -- follow the flush procedure below.
Normal in appearance -- continue with the next step.

Notice
When adding coolant, use DEX-COOL® coolant. If silicated coolant is added to the system, premature engine, heater core or radiator corrosion may result. In addition, the engine coolant will require change sooner-at 50 000 km (30,000 mi) or 24 months.

Notice
Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

8) Close the radiator draincock. Tighten.
Tighten the radiator draincock to 2 N·m (18 lb in).
9) Fill the cooling system through the surge tank.
10) Fill the cooling system with a 50/50 mixture of DEX-COOL® coolant and deionized water.
11) Start the engine.
12) Allow the engine to idle for 1 minute.
13) Install surge tank cap.
14) Cycle the engine RPMs from idle to 3000 in 30 second intervals until the coolant temperature reaches 99°C (210°F).
15) Shut off the engine.
16) Remove the surge tank cap.
17) Start the engine.
18) Allow the engine to Idle for 1 minute. Fill the surge tank to 12.7 mm (0.5 in) above the COLD FULL mark on the surge tank.
19) Install the surge tank cap.
20) Cycle the engine RPMs from idle to 3000 in 30 second intervals until the coolant reaches 99°C (210°F).
21) Shut off the engine.
22) Remove the surge tank cap.
23) Top off the coolant as necessary, 12.7 mm (0.5 in) above FULL COLD mark on the surge tank.
24) Rinse away any excess coolant from the engine and the engine compartment.
25) Inspect the concentration of the engine coolant.
26) Install the surge tank cap.
robsc501

 

Yes. Are you aware that Corvetteforum actually has more than one forum vendor dealer? Have you thought about calling the other one?

Btw, that straight heater hose piece is a metric size, NOT SAE, meaning that conventional 1/2" hose is too small and 5/8" hose is too big. IIRC it's something like 17mm or maybe 19mm ID. That hose is sold by the foot and some dealers do not keep it in inventory and will ONLY sell you a 50' roll. Other dealers may have it and will cut whatever you need and sell it by the foot.

 

Good info - I need to change the coolant in mine soon.

As for another source of the hoses, try Bob at Fichtner Chevy - a forum vendor.

 

Thanks guys. I now have the part numbers for the two molded heater hoses, 10407026; 10351595 the local dealership (Buick, Pontiac & GMC) gave up the info without me ordereing from them. I won't even go to the local Chevy dealer, bad, bad, bad but that is another story.

 

Rob, thanks for that info, it's filed away for another day.