Leaky rad fix

[rjkoop]

Is there anyway to fix a minor leak in a rad? It drips a bit from the bottom once the car is warm. Didn't want to bring it to a rad shop because I figure they would charge more than a new one from autoricambi.

[Ptoneill]

Actually my local shop recored mine fairly cheap, although for piece of mind nothing beats a new one. The cost of a tow would definately eat up any repair savings.

[wizard124]

Don't overlook the simple.

Mine was leaking from the bottom radiator hose. Tighten the hose clamp and/or replace the hose?

[rjkoop]

Don't overlook the simple.

Mine was leaking from the bottom radiator hose. Tighten the hose clamp and/or replace the hose?

Good point. I'll clean, run the car and try to pinpoint the leak. That would be great if it was a loose clamp.

[Exit98]

Richard,

Down here Advance Auto and Auto Zone both have tool lending. Not sure about up in the Great North.

Anyway, just last week I borrowed their Pressure Tester to find a minor leak after installing my new AR radiator.

Simple and easy to use and points you right to the issue.



Pump it up to 15 psi and the coolant will shoot out from wherever its leaking.

[rjkoop]

Richard,

Down here Advance Auto and Auto Zone both have tool lending. Not sure about up in the Great North.

Anyway, just last week I borrowed their Pressure Tester to find a minor leak after installing my new AR radiator.

Simple and easy to use and points you right to the issue.



Pump it up to 15 psi and the coolant will shoot out from wherever its leaking.

Cool. I might try that. Cdn Tire up in the Great (White) North has the tool for lending.

[rjkoop]

Don't overlook the simple.

Mine was leaking from the bottom radiator hose. Tighten the hose clamp and/or replace the hose?

Good point. I'll clean, run the car and try to pinpoint the leak. That would be great if it was a loose clamp.

Took a closer look and seems like it's coming from the radiator drain plug. I tried removing, using some teflon on the threads and reinstalling. Hopefully it will work. If not any idea what the thread/size is on that bolt? Rather not have to order and wait for autoricambi... if they have it. Or I may have to do this fix if it's leaking from the surrounding area...

http://fiatspider.com/f08/viewtopic.php ... 5&start=15 (1/2 way down the page)

[rjkoop]

So I think I made the leak worse by tightening the rad drain plug. So I'm thinking I'll need to do a repair. Anyone have any experience with brazing? I bought these. Not sure they will work but tomorrow is Canada Day (stores closed) so I bought them anyways and may try it tomorrow depending on what you guys think.

I was told propane torch doesn't get hot enough so this looked like it might work...


And 3 types of brazing and welding rods (wasn't sure which one to buy)...


Pic isn't great... one is aluminum (working temp of 700 degrees F), copper (working temp of 1300 degrees F) and bronze flux coated (working temp of 1600 degrees F). My question is which rod should I use on my regular rad (it's the regular fiat rad, no high performance aluminum one) and will the torch I bought work? The torch says is goes up to 2400 degrees F. Or maybe my standard propane torch (ie. no oxygen bottle) will work with one of these types of rods? I'm not even sure if the rad on my '81 is brass or copper.

[RoyBatty]

I took my Spider radiator into a shop last year for a minor repair.
It turned out I had a small lead from where the core is soldered to the tank on the bottom of the drivers side.
I got it home and installed it only to find that the shop had not been successful in their repair.
Disgusted with the inability of the shop and the 3 day wait, I took out by propane torch and the plumbing solder and flux I keep in the garage and went about the repair process.
It took me about a half hour of heating and reflowing the solder to get rid of the various little pin holes that can pop up.
But in the end I was successful.
To pressure test after each solder session, I would use my air hose and just spritz a little pressure into the radiator with some soapy water solution in the area where I had been working.
It's been more than a year since I did that and it's still holding just fine. Even in the current heat we are having in Nor Cal.
You don't want brazing rod, you need solder.
And I don't think the torch you are showing will effectively heat a large enough area.
These things dissipate the heat pretty fast. You need a larger heat source.
A little propane or map gas torch that uses the thread on bottle should do the trick. It's what worked for me.
Patience will serve you well in this process.

[DieselSpider]

You generally use a soldering iron for most radiator repairs and not a braising torch unless you have an aluminum radiator.

You need the get the area of the leak pristinely clean and use plenty of liquid flux with a dauber when you solder it. The gent who taught me used a set of copper soldering irons heated over a gas burner.



A heavy duty electric iron will work too.

Aluminum however can be very difficult for the novice to weld since it does not change color when you heat it until its too late and you then have a bigger problem to deal with than you started with.

[rjkoop]

After a bit more research and the posts here I'm going to try a propane torch and some solder. Or bring it to a rad shop and if they can fix it for <$80 get it done. Otherwise I'll just get a new rad.

[spider2081]

I agree with the liquid flux and solder iron. My first job out of school was repairing radiators at a manufacturer. We used small propane torch or solder iron. The torch takes more practice to and time to learn.

[So Cal Mark]

if the tubes are leaking at the header, a permanent repair is usually not possible. Tubes leak at that location because they are rotted out and there isn't enough material left to solder

[rjkoop]

if the tubes are leaking at the header, a permanent repair is usually not possible. Tubes leak at that location because they are rotted out and there isn't enough material left to solder

There is a leak (made worse by me tightening the drain too much!) at the drain plug. It has a crack on the rad and what looks like a sleeve (with a thread on the inside to fit the drain plug into) that fits into the rad.



So I need to fix the drain plug area and there is a small wisp of coolant steam when the car gets to operating temp from the top passenger area of the rad as well.

Here's a few other pictures of the rad. Doesn't look bad but what do I know?







Essentially if I can get these both fixed for <$100 cdn I'll probably go ahead and get it done in Ottawa. The new rad would be about $240 cdn or so after exchange and shipping.

Or maybe I can use epoxy???

https://www.youtube.com/watch?v=Z4Trxlk9P6g

[RoyBatty]

I wouldn't count on epoxy making an effective repair on metal.
Maybe in an emergency roadside repair situation, but not otherwise.