braveheart3158

Replaced my Radiator on my 94 with an A/C Delco I found at a dealer in the midwest for $275. I have taken a video and some pics that I can post later for other members.
I completely removed, cleaned and reinstalled the over flow tank

I have done a search on here and read a lot of posts on FLUSHing and filling the system but there seem to be to many different opinions. Some questions before I refill.

1-Is there just the one bleeder valve on top of the stat on the 94?

2A- How do I go about flushing the system with hose water?
2B-Do I use the bleeder valve during a flush?
2C-Fill system with hose water, run till hot, Drain and repeat till clear?
2D- Will sedament get stuck and clog new radiator?

3- Do I only fill the system ONLY through the Overfill tank or can I fill through the Radiator cap that is not located on the radiator?

4- When refilling with Distilled water and anti Freeze do I leave the radiator cap, bleeder valve open.

5- Should I put in a Water pump Lubricant? Is yes, what kind?

6- What is Wetter water? Do I need it?

thanks,
Ted

braveheart3158

One more.

Can I leave the car on front ramps while flushing and or filling system?

0Fred@ReverseLogic

The coolant fluid and water won't bother the Race Ramps. If the coolant was at operating temperature that could be a problem. But I don't think you would be working on the radiator with the coolant at 180 degrees.

Perhaps someone else can comment on what affect the angle of the car (while on ramps) would have on the flushing procedure.

John A. Marker

I would suggest that you remove the knock sensors (believe that there is one on each side of the block). This will drain the block where all your sediment would settle. I would then run hose water thru the radiator into the block to wash out as much as you can. Put the sensors back in and fill the system with water leaving the hose in the filler neck and the drain on the radiator open and start the engine and let it run. The water will flush thru the engine and out the radiator drain. Continue to run the water until it comes out clean. Let the engine cool and remove the sensors to drain the block of the hose water. Replace the sensors and fill with distilled water and coolant.

If you have not replaced the hoses, I would suggest that you replace all hoses including those that go to the heater. There is also a heater control valve made of plastic on one of the heater hoses. Chances are that is will crack, so replace that also.

The fill reservoir above the heater should be removed and flushed out as well. This has a low spot that also gathers a lot of sediment.

You will also see two aluminum tubes screwed to the passenger side of the wheel well that have factory crimped rubber hoses. (see.... http://forums.corvetteforum.com/c4-t...-95-vette.html
One has a hose that goes to the radiator and then to the fill reservoir and "T's" with a line going to the rear of the engine. These hoses should be replaced with stock 3/8 heater hose. Please note that the aluminum tube has a restriction (tube is necked down to a hole about 1/16") in the tube at the radiator end and is often plugged. I just replaced all the hoses on my friends 94 and this was plugged. When I changed my hoses on the 95 the tube was also plugged. Use a wire, compressed air or what you can find to open the hole and clean out the tube.

Yes, just a single bleeder valve on the 94. I replaced my thermostat and my friends with a 160 degree "Fail Safe" brand thermostat. They run about $32, much more expensive than a standard thermostat. BUT if the thermostat fails....if fails OPEN and not closed. I usually drill a small 1/16" hole in the thermostat to help bleed the air from being trapped by the thermostat before it opens. The Fail Safe already had a hole. I placed the hole at the front which is the high point. If your car is still on the ramps, this will help bleed the air even better.

No need to use the bleeder valve when your flushing the system.

When you are filling the system (if there is a separate cap for the radiator) I would leave the radiator cap on and fill thru the reservoir above the heater core. Leave the bleeder valve closed until you have coolant flowing thru the reservoir. Be sue to place rags under the hose around the hose where the bleeder valve is located. You will get air when you open the bleeder and coolant. You don't want any coolant getting to the OPTI. Be careful that the rags are away from the serp. belt. I would open and close the bleeder several times as the engine is run and heats up.

TommyFox

On a later c-4 I would invest in an Air lift. about $ 120.00. Vacuums all the air out and fills. Need a compressor.

Tom400CFI

Don't need one of those^
with all of that except that I'd add after the part in bold,
*disconnect your heater core hoses and run your garden hose water into one, catching what comes out the other. This will thoroughly flush the heater core.

Filling/bleeding is a breeze. On mine, I literally opened the bleeder, poured in the coolant, and when the bleeder started flowing, I closed it, then topped off the system and I was done. Piece of cake.

hemivett

I have prestone flush kits on each heater hose, (by the core) so I can flush it both ways, and when filling, I just leave the cap off the top hose, (since that is the highest point of the system) and when water comes out, she's bled, and full. h

TommyFox

How does the water get past the closed thermostat? Did you drill a small hole in it?

hemivett

I do have holes in both my t stats. I run a 180 in summer, and a 192 in winter, on all my cars. When I flush, I change the stats. So ya, when I flush, I pull the stat, then flush, then put in the new stat, and fill her up. h

Tom400CFI

Plus, the stat I bought had a small hole and valve to vent air when filling. I think that's what it's for.

Cruisinfanatic

why?

TommyFox

I see. Aitrlift vacuums air from both sides of the stat and I hate extra work. Plus I use Evan's coolant and I never have to flush my system again ever. I you are flushing once a year you could save money by using Evan's. Also, wasting your time switching stats. Car is going to operate at the same temp no matter what stat you use. One is just going to open faster than the other. 192 will allow your car to heat up faster in the winter but that's about it.

Just for the hell of it I have experimented with a 160, 180 , 190. Car runs the same temp. about 190 max.

hemivett

I use the 192 in winter, to keep my in-vehicle heat a little warmer, and in the summer I dont need it that warm, and Im old, and old guys get scared when the temp is so high. Lol. Stock it ran from 198-228, now with an adjustable fan switch, I can keep it at whatever temp I want. Anything below 180 the car doesnt like, (also have tried others too) so thats where its at. h

TommyFox

[QUOTE=hemivett;1583621034Anything below 180 the car doesnt like, [/QUOTE]

180 degrees or a 180 stat?

hemivett

Ive always drilled a hole in mine, if it didnt have one. It does help with filling, but I always did it so in case it stuck shut, I would be less likely to pop a headgasket. h

hemivett

It runs from 178-184 with the 180, and is very smooth. Runs a bit rougher/richer below 175. h

TommyFox

What year is your car? Besides fan switch what mods have you done?

Just getting info for those who have overheating problems.

hemivett

Its an 84. As far as cooling,,,, Not much. New heater core, and new Summit aluminum water pump. Will do an aluminum radiator when mine dies, or it gets a little more motor, but as of now the stock one is working fine. The key is to get the fans working properly, by either an adjustable fan switch, or a lower degree CTS. h http://www.jegs.com/webapp/wcs/store...kMODEL=1548239

TommyFox

Never owned an 84 but the 85 on up TPI's have a partially blocked rear coolant passage from intake gasket by design which makes these cars run hotter by design for emissions. Going to a fully open one drops the temp a good 10 degrees, at least from my experimentation and others that taught me this years ago.

Cruisinfanatic

220 is not hot for a C4. Won't get there anyway with any temp stat if you radiator is clean.
Not designed for a stat as low as you put in

the only reason your car runs aroung 180 is because of the low temp stat and the fans running full blast.
180 is not warm enough