I just spent the weekend replacing neglected parts on my 91 F250 and thought I would replace my leaking radiator as well.
Big mistake! The new one was cladded in a plastic housing and was light as a feather. I installed it anyway, then replaced the T-stat and all the hoses.
Topped off the system with green coolant and distilled water. after some burping everything seemed fine ......wrong! Can't drive down the driveway with out in going into the red.


Long story short, I'm putting my original back in.
My question to you fine people is, If my old one is just leaking from the top seam, can I fix it myself? JB weld? Braze? And, is there something else that could be causing my new on to run so hot? I'm stumped.
Your thoughts are appreciated.
Thanks!

 

sorry to hear of your rad woes ..

i will give my take on repair first ..

most likely it's not the top seam that's leaking .. it might be
but on mine it's the tubes themselves where they insert to the side of the core

i was going to repair mine

take off the top and bottom tanks

resolder the tubes .. then replace the top and bottom tanks and seal well

thing is i used a full oxy acc bottle setup removing just the top tank

30$ worth of gas

when i got it off i found the problem wasn't material

it was some lazy ******* in 1985 who only soldered 3/4 of the first row of tubes

and soldered the corners of the other 2 .. i can hear him now

" that'll hold "

well it held physicaly tight .. but after 30 years of expansion those remaining 80? un soldered .. just pressed in tubes began leaking from the ends of the cores

so .. here was my dilemma

i COULD fix it

BUT here was my math on getting there

15$ in lead bars from the plumbing supply store 5$+ in flux and wire solder

30$ in gas to remove the other tank

30$ in gas probly to reseal tubes to core on both ends

maybee 2 more 30$ sets to re install the tanks

not to mention each of these gas refills requires a 30 minute trip to town

by the time i fixed the old rad i would have consiterable money and time into it

and even then the brass itself is old and i wouldn't be 100% assured of a leak free seal

with alot of surface to solder and my non expert rad repair slillz

......

ultimatly i abandoned the project and my ol' rad still sits with the top off

. . just too much money to get er' done

i wen't out to pick a part and hauled in a clean late model 460 radiator and made some hose adaptations and it's worked great so far .. it's also just a plastic tank aluminum tube thing .. but i like it haven't overheated yet myself .. may be different in your truck .. i got the idea from another idi guy who had run one for years without incedent .. so try if you like or dump the plastic and aluminum .. i'm still in the experimenting phase with this new plastic/aluminum rad .. only been on 2 months now .. no overheats yet .. but august with a trailer on the freeway with a/c will be the true test .. i will post up if it fails

the whole kit retrofit cost me 60$ so i don't care if it gets hot and i need to figure out something else

as for a good new setup .. .

someone just the other day found a brass 4 row 'hear say' no proof that it's the real deal yet .. but you can buy one and let us know

https://www.ford-trucks.com/forums/1...-radiator.html

also a good number of peeps are running the champion 3 row radiator from amazon with great success .. this is likely going to be my radiator choice if i need to upgrade again

 

Thanks for the info! Yeah, sounds like another nightmare to me. I may just take my old one to a shop and see if its fixable.
Any ideas on why my new one isn't functioning properly? should I bypass my AT pre-warming line? I have replaced a lot of radiators and this is the first time this has ever happened.
Thanks

 

well i would leave the AT line in there

did you use a genuine ford dealership or navistar thermostat ?

parts store thermos' never work properly for our engines // hear say says on the net

you said you burped it right .. you did took off one hose at the firewall where it goes into the heater core until coolant came out it and air was fully purged

was it overheating before the new rad or was it just leaking

if you put in the old rad and air purge and it still overheats then it's the thermostat

if you put in the ol' leaker and problem solved then just need a new rad setup

just fyi what brand is giving you these problems so we can warn other not to use it .. was it billed as a direct replacement part ?

 

Its a motorcraft T stat. The ol leaker never over heated. I was just thinking I must still have air in it. I did not disconnect the heater core hose to purge it.....I'll try that tonight before I turn my .38 on this new radiator Ha! Thanks for helping me get the thought process going.
I'll double check the radiator brand. It was a direct fit from Napa.

 

If your cooling system can't handle going down the driveway, its not your radiator that's the problem unless its totally clogged from the factory.

Before blaming the new rad I'd say you still have some serious air trapped in the engine. Also what kind of temperature gauge are you running? Stock is borderline useless.

 

Yes, the stock gauge is useless. that being said, it never crossed the middle until the parts were replaced.
I am thinking air being trapped is my last resort. gonna try and bleed it really good tonight and see if it works. Then get a real temp gauge for it

 

Thats what I was going to say. A lot of us are running aluminium rads with plastic tanks with no problems. A lot of people were having trouble getting one that wouldnt start leaking a week later, but I highly doubt your new rad is causing an overheating problems. Is it boiling over overheating or just your gauge showing high. Could be a gauge failure.

 

Yeah no way a radiator is causing that overheating. When I installed my last water pump I had trouble getting air out after about 20 minutes of running. It hit 220 on my gauge mid gauge on the factory gauge. I ended up releasing pressure topping off and the thermostat eventually opened and it's been fine since.

If you think it might be the radiator check the top and bottom of radiator with an ir gun, I bet it's not 200 because you're not getting flow through it. The temp sensor is in the head not the radiator.

 

yep i completely .. or almost completely drained the coolant when i had put mine in and i couldn't get it to 'take' or start pulling in enough to get it to the water pump to start circulating the fluid until i took off the heater hose ..

i took off one side and added my coolant into that hose directly with a small end funnel because it is a higher side and helps getting it to prime .. then left the funnel on and started it and it added a little .. then finally it puked some coolant up back out of the heater hose and i stopped the engine ..

hooked up the heater core hose again .. then topped the rad .. and it was primed .. may have to top the rad a few times .. hope this fixes it

also here are a few pics if anyone interested .. of the tank off brass rad .. i took one tank off and here's what it looked like inside .. if you ask me (and you didn't) i would say only 1/3 of these tubes was properly soldered into the side of the core ..

and you can see why you are unlikely to see these made in america at this time ..

they are made of only 2 things .. brass and ALOT of lead .. that's kinda partly why i quit fooling with it also .. i'm not a big afraid of a little lead .. but better safe then sorry .. this is alot of lead to deal with

* * also i did some work on my truck to day .. turned a pulsing rotor (smooth now) and trued (shaved high spots) off another tire // but i'm not doing a writeup on these because i don't want anyone else to try .. not safe to do unless you got the right stuff and ben doin' it before

 

Something to think about:
If you pull off the t-stat cover/upper radiator hose casting, inside it there is a little passage with a ball bearing in it.
That is supposed to let air past without letting water. If you simply /remove/ the ball bearing and make sure that little passage is clear, you'll have a lot better time bleeding the system(as in, no trouble at all). And it won't affect warmup time at all, as far as I can tell.

 

Thanks guys! The ball bearing doesn't seem to be in there anymore. The radiator will gush over when it gets hot but the heater hoses and upper hose seem to be empty. Been working so haven't had a chance to pull the heater hose and try to prime it.
Thanks for the help ill keep you all posted

 

I have actually found 4 places to get brass and copper radiators. Got an email from autozone that says theirs is a four core. Pepboys on ebay, advanced/carquest radiator and rockauto. I've been told that there are two sizes though. One with ac and one without. Not sure on the sizes.

 

There is nothing wrong with aluminum radiators, the problem is the low silacate extended life coolant having a pH of 10.0-11.0. It's way to high for aluminum and will eventually cause corrosion. Running a molybdate additive will prolong the life of an aluminum radiator or heater core but failure is inevitable at that high of a pH. The silicate actually protects aluminum, but can cause under deposit corrosion on the cylinder sleeves.

 

I've got the green stuff from napa that says its "formulated" for diesel engines. should I still use an additive with that? If I get this thing cooling properly....