Nothing coming out of radiator drain plug

[socialDK]

I went out to install a new thermostat when I opened the drain plug nothing came out. I did it with the cap off and on. Is it safe to assume the radiator is clogged and this is whats caused my erratic temp gauge and I should replace the radiator?

 

[doonze]

I would point you to the thread in my sig, but IDK.... NOTHING from the drain plug??? Wow.... but if you wanted to save it I bet we could....question is..... do you want to bother or just replace the thing....

If you have LOT'S of time, try and save it, if you have lots of money then buy a new one.....

But if it's THAT clogged...then I vote just buy a new one....

 

[geoph1986]

Sometimes the drain plug get clogged. To drain the system , just disconnect the lower rad hose and have a drain pan handy to catch the coolant, it comes out fast, and if you're not quick enough you'll get a coolant bath. If you think it may be clogged/getting clogged, once empty shine a light down the filler neck and look where the tubes come into the header. If you have fuzzy growths or gunk closing the tubes you should see it. You can also easily do a flow test. To do this, disconnect both upper and lower hose from the rad. Plug the lower outlet and fill with water. Once it's full, pull the plug and see if the water gushes or trickles out. If the rad is flowing slow and isn't leaking, you can pull it and have it pressure flushed and pressure tested. The downside to this is that sometimes the pressure flush will make a weak rad leak after. If you don't want to pressure flush it try flushing it without pressure, doonze has a sticky at the top of this forum and it's quite thorough.

 

[shaggymane]

I went out to install a new thermostat when I opened the drain plug nothing came out. I did it with the cap off and on. Is it safe to assume the radiator is clogged and this is whats caused my erratic temp gauge and I should replace the radiator?

You say you opened the drain. You don't say if you tried to unplug it.

Did you take the plug all the way out? It does keep on unscrewing till you can seperate it from the radiator. Mine did the same as yours. I just pushed the plug in and out to disturb the blockage. first *dry* mud came out, then wet mud, then sludge, then dirty water, finally coolant.
Try some things to unplug it if you haven't........a piece of wire.

WITH THE CAP OFF if you have compressed air, turn the regulator down to 15lbs, blow in the drain. up it 10lbs try again.

As doonze says, he's got the ultimate rad thread.

My temp gauge has been pegging the hot side on startup and then slowly coming down. But then all my gauges have been going one be one.

 

[Tony H]

There's a good chance the radiator is fine, just gummed up at the Drain.

Take it all the way out and see if it flows. a careful poke with a coat hanger might be all it needs.

ShaggyMane: it sounds like your T stat is getting lazy. Sometimes the brass plunger gets a ridge in it from going up and down and then can hang up until the bi metal spring pressure gets real tight and pushes it past teh ridge.. then your gauge will show it cooling down rapidly.

 

[socialDK]

Ok I pulled the drain plug out and still no flow. I tried a screwdriver and a nail punch. Im going to try the super flush sticky and hopefully purge any dirt and clogs. I bought a new thermostat is it supposed to come with a new gasket or is that sold separate?

 

[Currency]

Ok I pulled the drain plug out and still no flow. I tried a screwdriver and a nail punch. Im going to try the super flush sticky and hopefully purge any dirt and clogs. I bought a new thermostat is it supposed to come with a new gasket or is that sold separate?

The gasket is generally packaged with the thermostat.

If I were you I would simply pull the lower radiator hose off and drain it that way. Then take a water hose and spray it in there towards the open drain plug. Then try spraying it up into the open drain plug. Maybe the force of the water will break whatever is up there lose?

 

[socialDK]

So I drained the system and sprayed water in ever hole the lower hole and the drain plug mostly and it did nothing. I looked down the filler pip and saw nothing special. Would it help if I pulled the whole radiator and tried again? I will add a prestone flush kit but I'm not sure which heater hose to put the tee on. Is it the hose going to the top of the engine or on the left side of the water pump?

 

[Tony H]

Very odd that you can't get it to clear. I think I would pull it and get a better look into the Drain plug.
Careful when disconnecting the trani lines.

 

[corkey]

i would pull the rad, it has a lotta junk in the bottom if the drain wouldn't unplug after all of that ,
i would find out why, maybe use hot water in the rad and keep running it into the rad to see what comes out,, and seeing if you can get a piece of wire or something thru the sludge where the drain plug goes,,

i had an issue with mine a bit ago, previous owner and Bars Leaks, must have used 5 packs,, once i got it cleaned and drain open and clean it truned out the leak was from the overflow hose to the catch can,

 

[doonze]

Yeah, I'd pull the radiator, not hard at all, instructions in my sticky. Don't bother with the flush stuff until you can get flow from the drain hole.

I would try using a sprayer on the drain hole once you have it out of the truck. Just keep hitting it with the water for awhile and see if you can knock that block out.

Problem is, the way the radiators seem to be plummed that "channel" down there that feeds the drain plugs NEEDS to be unclogged to flow water right, I'm going to to take my old radiator apart and find out why next weekend I think.

So, if you can't get it to drain right, replace that puppy becuase I'm going to bet you it will never cool "right". Course not right might be good enough unless it's under extreame load....

 

[geoph1986]

You said you got the system drained. How did you drain it? Pull the lower rad hose? If you did it that way, what was the flow out of the lower connection on the rad like? Slow, fast? I very rarely will use the drain plug to drain them because they get filled up with crap really easily. Also, before you go and spend a bunch of time trying to flush a potentially plugged rad, what does the epoxy that joins the tubes to the tank header look like? If it has cracks, or is separating don't even bother trying anything. Just toss it out and get a new one.

EDIT: Sometimes the rad will look ok at the top (looking in filler neck), but near the bottom it will look like this:

Make sure you do a flow test so you're not wasting your time.

 

[socialDK]

EDIT: Sometimes the rad will look ok at the top (looking in filler neck), but near the bottom it will look like this:

Make sure you do a flow test so you're not wasting your time.

How do I pull apart the rad like the image? I pulled it and sprayed off the gunk on the outside.

 

[doonze]

You don't want to do it, we have a poster here who used to work in a radiator shop, and even with the special tools designed to "reclamp" those tabs it would mostly never not leak afterwards....

Can it be done...yes
Should it be done.....no

At least according to the only expert I've heard talk about it.... I'm sure it's been done without a bad result, but I'd only do it as a last ditch effort.

 

[Currency]

You don't want to do it, we have a poster here who used to work in a radiator shop, and even with the special tools designed to "reclamp" those tabs it would mostly never not leak afterwards....

Can it be done...yes
Should it be done.....no

At least according to the only expert I've heard talk about it.... I'm sure it's been done without a bad result, but I'd only do it as a last ditch effort.

I've done this before. Why did I do it? Because someone gave me $15 for a used radiator which I didn't have a good one for the truck they wanted it for. So I poped the ends off of a good one and put the correct ends on it. I just talked to her about it a few days ago and she said it still doesn't leak. It's been several years.

But then again I've never seen one look as bad as the picture above before. It can be done with regular shop tools fairly easily but I don't recommend doing it. I told her I switched the ends on it so it would work in her S-10 and that it may leak a little bit. She didn't care because it was only $15 Vs. having to pay over $100 locally for a new one.

 

[geoph1986]

Recrimping these rads is hit and miss. The proper way requires a rack to hold the rad and a special crimping tool. I know of people using channel lock pliers to recrimp them, but that too is hit and miss. The pic wasn't to give you the idea of pulling the tanks off, but just to show you what it can look like. The rad in the pic failed because of Dexcool coolant being absolute garbage (it's a GM thing). If you think your rad may be plugged, do a flow test. Remove it from the truck, stand it on end with the lower connection to the ground and plug the lower connection. Then fill it with water. Once it's full, pull the plug and see how quickly it drains, it should only take a few seconds. If it's plugged, it should be fairly obvious.

we have a poster here who used to work in a radiator shop...

I think you mean me

 

[socialDK]

I pulled it out and determined replacing the radiator is the way to go. I'm considering getting one from a friends family junk yard/pick and pull if they are pretty sure it will work. My question is what years will work in my '91 2 door 2 wheel manual?

 

[spankmeplz]

Check your local auto parts store. Installing a used radiator means another persons problem. It may cost a few dollars more, but it is cheaper than replacing a head or an engine.

 

[geoph1986]

According to Hollander:
Manual trans (no A/C)
EXPLORER 91-94 MT, w/o AC
MAZDA B-3000 94 MT, w/AC
MAZDA B-3000 94 MT, w/o AC; super cooling
MAZDA B-4000 94 MT, w/o AC; std cooling
MAZDA NAVAJO 91-94 MT
RANGER 92-93 6 cyl, MT, w/o AC; 4.0L
RANGER 94 6 cyl, 3.0L, MT, w/AC
RANGER 94 6 cyl, 3.0L, MT, w/o AC; super cooling
RANGER 94 6 cyl, 4.0L, MT, w/o AC; std cooling

Manual trans (w/ A/C)
EXPLORER 91-94 MT, w/AC
MAZDA B-4000 94 MT, w/AC
MAZDA B-4000 94 MT, w/o AC; super cooling
RANGER 92-93 6 cyl, MT, w/AC
RANGER 94 6 cyl, 4.0L, MT, w/AC
RANGER 94 6 cyl, 4.0L, MT, w/o AC; super cooling

Auto Trans (no A/C) standard cooling
EXPLORER 91-94 AT, w/o AC; std cooling
RANGER 94 6 cyl, 4.0L, AT, w/o AC; std cooling

Auto Trans (no A/C) super cooling
EXPLORER 91-94 AT, w/o AC; super cooling
MAZDA B-4000 94 AT
MAZDA NAVAJO 91-94 AT
RANGER 94 6 cyl, 4.0L, AT, w/AC
RANGER 94 6 cyl, 4.0L, AT, w/o AC; super cooling

Auto trans (w/ A/C)
EXPLORER 91-94 AT, w/AC
RANGER 90-91 6 cyl, AT, 2-1/8" thick
RANGER 92-93 6 cyl, AT, w/AC

All of these rads will bolt in, the only difference is the rads fluid capacity (unless your truck has an auto trans, you need the trans cooler). I would highly recommend that you DO NOT use a rad with a smaller fluid capacity than the one that's in your truck already. Also, when looking for a used rad, make sure you look at the epoxy where the tubes meet the tank header. If the epoxy is cracking, or separating from the tank header, move on to the next donor. Don't forget to have it pressure tested before installing it. It sucks to have to redo a job because the replacement part is faulty. For the $120ish it will cost for a new one, you might just want to do that and save yourself a headache.

 

[socialDK]

So having no other vehicles(my motorcycle is out of commission till I get new parts),no income since I lost my job and having lunch with a female I decided to try to unclog it once more. This time I was successful. I was not ready for what came out. Aside from the normal dirt and debris I got what looked like black rubber gasket pieces kind of like rtv, the stuff that comes in a tube, coming directly out of the rad. not the hoses. A few pieces and a couple 1"-1.5" long. Any ideas where they came from? My fear is something internal is going to fail.

And I will be getting a new rad. asap.