Hey all. Decided since I drained all my coolant I went ahead and replaced my t stat, upper and lower hoses, along with all the misc 5/8" 90's and anything coolant related. Have 2 problems: freeze plugs. The one closest to the block heater had a leak. I ordered a set of 3 billet alum ones that tighten like a toggle bolt. Fixed that one no problem. Knocked out the last two towards the firewall and dang! Can't get those in cause of the tranny cooler! Any suggestions other than disconnecting my ATF lines at the bottom to move that thing out? Hate to lose brand new ATF ! Lastly, the petcock wing nut ripped off as I loosened it to drain my radiator. Is the petcock brazed onto the radiator or can I unthread the unit and replace the entire petcock? I have the replacement from orileys it is 1/4" npt. I didn't want to throw a wrench on there till I checked in here. Thanks for assistance. Man I thought I'd put a killing on those plugs, but now I'm stuck

 

if you pull all that, do brass plugs, your paying for coolant neglect, add 5yr coolant, after 4 years of service change again, or has petcoks by application

 

I have a couple of stock radiators. The petcock looks like it's soldered or brazed in.

 

coolant neglect?! I change my coolant along with a flush every 12,000 miles 15,000 max. And I filter my coolant to boot! How about its just because its a 21 year old truck is why. You go to cummins and buy freeze plugs isn't it a wonder they sell stainless steel vs the plain old steel they used 21+ years ago? Brass bull puckey on that. Already have the billet ones. My post was inquiring for assistance not to get condemned. Orileys did give me the petcock for my application. My question was wether the oem petcock was brazed or threaded on. Geez

 

Thanks for the heads up

 

Looks like you might be able to drill it out and tap it 1/4" npt. You'd have to pull the radiator to do it. That is not a tough job.

 

Got it all fixed. Had to drop tranny cooler. Only lost 1/2 a quart. All wrapped up. Freeze plugs, as all have told me prior to attempting this, are easy to R&R . It's getting to them that's the toughest. I also bought the billet rear plate that bolts onto the rear of the block above the tranny and engine mate up. That, will be for another day!! The 3 at the side of the block was enough. Gonna pay tomorrow. Hello Advil !!

 

The petcocks are threaded into the bottom tank or side if you have a cross flow,
When I installed my new custom radiator I installed a 1/4 turn ball valve to drain my radiator.

Jim

 

I discovered that you can drop a hose in the filler hole and siphon out all the coolant into a container. It's much easier than trying to recover coolant by washing off greasy front end parts with it.

Drain fitting on the Mishimoto radiator is a brass plug. It will probably never be backed out.

 

so what type came with our 1st gens? Am I understanding that some models came with a cross flow with a replaceable petcock while others like myself might have a different type with a brazed on petcock? It sure looks brazed on unless it is gobs of paint

 

1991and earlier non-intercooled came with a down flow (tanks on the top and bottom) and the drain petcock should be on the drivers side on the bottom tank and it should be threaded in.

1991.5 and later with intercooler came with a crossflow radistor (has the tanks on the sides) and the petcock should be on the drivers side near the bottom of the tank and also should be threaded.

Now aftermarket and newer crossflow radiators will have tanks made out of plastic or fiberglass and are crimped on to the cores.

The petcock usually has a molded in bung at the bottom of the tank and the petcock is replacd by unscrewing the old stem and screwing in the new replacement stem resembling a plastic wingnut with a rubber washer.

I have never seen a soldered on petcock but as yet I have not seen everything there is to see.

Jim

 

You must have a cross flow, I hit the core about 2 inches below the filler neck though I can see what you are talking about.
Jim

 

so your thinking with my 93 cross flow rad I should be able to unthread the pet **** valve assembly and thread a new one on? Sorry if I am suspicious about this- dont want to have to but a new rad cause I cracked it at the pet **** location

 

Is there any way you could take a picture of it?

I would think it was threaded in,
Maybe the paint on the threads is deceiving you, clean it off using a stiff wire brush.

Jim

 

Good idea on the wire brush. See? The simple things we overlook but someone else suggests. That's why I love this site. Will look into it maniana