This is the darndest thing I have seen on a vehicle. The petcock for draining the radiator is on the lower, driver side, back of the radiator. It is open all the way to shut it off?? That's the way it was when I found it.

When I turn it the other way, it flows in a drip, instead of a flow. If I turn it all the way in, it keeps dripping. If I turn it all the way out, it stops the flow.

I am trying to drain the radiator and having two problems. Obviously the petcock, but I am ready to pull the lower hose and get a bucket. The next is that the only manual I have for this thing is actually for the Ram truck. In that manual, there is an engine block petcock to drain the coolant from the block. I cannot find this anywhere on my van. Does someone know where it might be?

 

I knew this wasn't going to go smoothly!

If you're getting nothing more than a drip out of the petcock at full open, then you have deposits in the bottom ofthe radiator which are impeding the flow. Forget the petcock, close it and pull the lower hose. This is a better method anyway because you can get a high velocity flush. No need to open the engine block either. Here's what you do, disconnect the hose from the heater hose vacuum valve on the heater core side. Take your garden hose and press it tightly to the heater hose you just disconnected. Have someone turn on the faucet and let it run until you have clean water running out of the lower hose. (This also flushes the heater core.) After that pull the radiator cap and stick the hose in there and blast the radiator clean. Now blow into the heater hose to try and push as much water out of the system as you can to make room for the antifreeze. After that change the t-stat and put everything back together. Put some antifreeze and water (50/50) in the overflow bottle to fill it up. Dump the remainder of your two gallons of antifreeze into the radiator, run the engine to temperature and top it off with water. After it sits overnight check your overflow bottle and fill accordingly.

 

Alloro, I am using a flush right now. The radiator does look pretty bad on the inside. I gotta tell you though, my manual for the 5.2 truck looks nothing like my van. In the manual I have, it shows that you have to remove the generator (I assume they mean alternator) mounting bracket. The schematic they show is not the same as my van.

From what I can tell, I would need to lower the alternator on the pivot, to remove belt tension. Then remove it and get it out of the way, somehow. Then, I might have good access to the thermostat. Does this seem reasonable to you? If it is, then I should replace the belt, because it is cracking.

Tomorrow,I will take a digital pic andpost a link to it. The light is lousy right now.

 

Ditto post, but to keep the info in this thread too ...

Remember to use DISTILLED water when refilling the radiator with the proper coolant mixture. This will greatly extend the life of the radiator, the thermostat, water-pump, and HVAC heater core. Distilled water doesn't have the other tap water minerals that will use up the coolant protectant inhibitors.

Knowing that there has been junk clogging up the radiator, get at least six of more gallons of DISTILLED water from Wal*Mart 0.68 cents a gallon or at a local supermarket for nearly the same price.

The last thing you want to do is to replace t-stat and HVAC heater core! What a chore that would be.

As for the coolant, and knowing that it had sludge mess, I would HIGHLY recommend Sierra PG coolant (or equal propylene glycol) rather than the EG (ethyelene glycol) coolant at this point. The PG will protect the metals better and heal the hoses to prevent premature bursting. The old saying of pay me now with EG coolant or pay me later with PG coolant applies here. You may get more life from your cooling system components with PG after the mess is flushed out. PG is only a few dollars more, but will be worth savings in the long run. PG isn't a long life coolant, but in this situation, it will protect much better with the distilled water.

 

Don't try and remove the alternator with the belt tension still on it, unless the name "Jimmy Two Fingers" is appealing to you. [sm=outcold.gif]

There's a tensioner pulley (not the fixed pulley) where you put a wrench on the pulley bolt and pull it over enough to slip the belt off. After that you have to remove the alternator to be able to access the t-stat housing. It's a real tight fit to get the t-stat housing bolts out, but it's not as bad to take apart as it is to put back together, because getting your fingers in there to insert one of the bolts is tough to do while keeping the housing from sliding around. If the belt has cracks then yes you should replace it while you have it off.

 

http://www.pavementsucks.com/tech/timingchain.php

Look at the second picture down. Down and to the right of the alternator is the fixed pulley. Down and to the left of the alternator is the tensioner pulley/arm that you have to put the wrench on to release tension. The tensioner pulley is 1/2 cut off in the picture, but the layout should give you a good idea of what I'm talking about.

 

I just went through the same thing on my '92 5.2 (318). I just bought it so I'm chasing down every possible problem I find. I removed the alternator, AC compressor and the cast Aluminum support bracket. Good thing because I found the bypass hose (engine to waterpump) in bad shape and replaced it. As long as you are going to replace the t-stat, I'd do the bypass hose as well. With the AC compressor and the bracket out of the way getting at stuff is a whole lot easier.
I also replaced the belt and kept the old one as a spare.

My radiator looked like a sewer and even after a new t-stat and flushing I was still having some temperature problems. Oh yeah, I found that the water temp sensor was broken also when I tried to take the wire off. Good thing to check when you're "in there".

I ended up buying a new radiator from http://www.radiator.com/. One of the best internet purchasing experiences I've had. You actually talk to a computer on line and give it all the info. Then they call you back. I got the call within 5 minutes. Confirmed the info. Provided the credit cardnumber and had the new radiator sitting in my drive way the next day. 135.00 bucks.