HELP!! radiator issue

[BarryK]

am I screwed??

When I first started this project on my car a few weeks ago I had to drain the coolant but the radiator draincock was broken and wouldn't open so I had to completely remove it and I bought a replacement unit. I noticed while removing it it was very difficult to take out as if at some point it had been previously removed and put back in wrong but I never looked at the threads closely. I went to put the new draincock in today and before I did I went to use the thread chaser on it to clean it up. I noticed the threads are all screwed up on the radiator. The last person to put the old draincock in obviously had it crossthreaded. I was able to get the thread chaser in without too much trouble at all and once started it went up and down very easily but I can see that the first half of the threads are all messed up but gets better as it goes up.
After using the thread chaser a couple times I tried the new draincock but can't even get it started. I don't want to force it and make a bad situation even worst.
What is my best bet on this problem? I REALLY can't afford to spend $700 on a new radiator this year and I really believe that is is a fairly new repro date-stamped replacement radiator within a couple years at best before I bought the car so it's not old and doesn't need replacing.
Can this thing be saved in any way?

Barry

 

[IH2LOSE]

What did you use as a thread chaser, I think the drain cock is fpt threads it wont be the same as a normal tap and die set,

If you used a normal fine tap this may be the problem

 

[IH2LOSE]

What did you use as a thread chaser, I think the drain cock is fpt threads it wont be the same as a normal tap and die set,

If you used a normal fine tap this may be the problem

FPT means female pipe threads

 

[BarryK]

Larry, yes I've now learned the difference between regular threads and FPT. The thread chaser was a regular SAE but even now knowing I may have made it worse unknowingly, it was pretty f**ked up when I started.

 

[ChuckG]

Doesn't look TOO hateful. Does the original petcock fit and tighten at all?

I wonder if pipe dope/thread sealant would help. Also, I wonder if an oversize petcock is available. Chuck

 

[BarryK]

Chuck
No way the old petcock will go back in. The threads on that are totally mangled. That I noticed when it was removed, I just hadn't previously noted the threads on the radiator itself got damaged that badly also at the time.

Well, I really didn't want to pull the radiator out but I think I'm going to have to. IF I decide to try to retap it with a proper NPT tap I wouldn't want to attempt as a wierd angle from under the car and if i'm real smart about it I'll just take it to a good radiator shop and see if they can repair the threads for me at a reasonable price.
I looked at my shop manual last night and it looks like pulling the rad out of the car isn't really all that difficult, especially since the upper and lower rad hoses and the fanblade and waterpump are already off. Looks like it's just a matter of removing the shroud (6 bolts) and than removing the upper mount bracket. The hood can still stay on the car at least.

it's always something!

http://69.253.166.197/page1/page76/page83/page83.html

Here is a link to pics of the unit. Is it possibly to identify the unit as a DeWitts or anything else? I also tried to get close-ups of the damaged threads but the pics didn't come out well enough to see any detail.

 

[ChuckG]

I'd try buying a new petcock first, one without boogered threads.

It's not that tough, at this stage of the game, to pull the radiator. As you said, 6 bolts on the shroud, the top bracket, and yank it out.

I just put my new DeWitts in the car a few weeks ago before tearing the rear end out. Took me about 4 hours total, working alone, and pausing to clean stuff up as I went. Chuck

 

[BarryK]

Chuck

I already have a brand new petcock for the rad, I was about to install it when I noticed how messed up the threads on the radiator were.

Yep, looks like my work today is set up for me - have to pull the radiator out.
Tomorrow i'll call Tom DeWitt and see what he recommends. A friend suggested local radiator shops may not be set up to properly deal with this so I may be better off trying a local machine shop or even having to send it back to DeWitt's for repair (my friend says it's definately a DeWitts unit based on my pictures)

 

[ChuckG]

It sure looks like a DeWitts. Another alternative....try to find someone local to you who can TIG weld. They could replace the bung, or add some aluminum and re-tap it for you.

OR....you could just try some epoxy/JB Weld, etc. and re-tap it yourself. Chuck

 

[IH2LOSE]

Barry dont get excited,this is the kinda stuff you will always encounter on a old car.

The cars is old,every one has been in it before you.Relax

Before you pull the radiator snap a picture of the threads that we can all see.

 

[IH2LOSE]

Sorry I just seen your link to the radiator pet cock

 

[John Mcgraw]

Barry,
You can probably salvage the hole after you get it off. With the tapered threads of a pipe tap, I would give better than even odds that you can get it tapped out and sealed up again. If not, I am sure that Tom can weld a new bung in to replace that one.

Regards, John McGraw

 

[BarryK]

ok, here is the really big question?
with my lack of experience and never having retapped before, what are my chances of doing it myself and getting it done correctly? Or am i better off not touching it and leaving it to a machine shop or shipping it out to DeWitts?
I want it done right and I don't want to make it even worse than it is obviously.
I am just looking for what my best course of action is

 

[BarryK]

ok, the rad is out of the car.
What a PIA getting to those six fan shroud bolts without removing the hood.
i think when it's time to reinstall this thing the hood is definately coming off first.
Torrow I'll call Tom DeWitt and either ship it out to him for repair or see if he thinks a local machine shop can handle the repair.
I don't think i want to try taping it myself with a NPT tap or i run the risk of really ruining this rad.

 

[Dannoman]

Barry,
I think I'd try finding someone local to fix it for you. Can't imagine that it would cost much.....plus you wouldn't have to dink around with packing and shipping the darn thing. Sounds like it'd be a pretty easy job for a radiator shop.


Danno

 

[Samauriwarrior]

Contagion

ok, the rad is out of the car.
What a PIA getting to those six fan shroud bolts without removing the hood.
i think when it's time to reinstall this thing the hood is definately coming off first.
Torrow I'll call Tom DeWitt and either ship it out to him for repair or see if he thinks a local machine shop can handle the repair.
I don't think i want to try taping it myself with a NPT tap or i run the risk of really ruining this rad.

BE CAREFUL I HEAR THERE IS A SERIOUS WINTER STRAIN OF "whileyouareatityoumightaswellas" FLOATING AROUND!