Skip Navigation LinksHome > G503 WWII Ford Willys Jeep Restoring > MB GPW G503 WWII Jeep Repair a Crack in Radiator by soldering
If this helped...
MB GPW G503 WWII Jeep Repair a Crack in Radiator by soldering

This article shows how to Solder up leaks on your MB GPW G503 WWII Jeep Radiator

This article applies to both Willys MB and Ford GPW WWII Military Jeeps 

1. Many restorers develop small radiator leaks even after they may have recently had it recored. This radiator was bubbling out the neck area of the inlet.

2. In order to make a solder repair on a radiator you need steel wool to clean the area to be soldered, solder, flux, and in this case, a micro torch. You can use a soldering iron if it is a good, quality one.

3. Cover your radiator inlet, and use the steel wool to remove the paint and clean the area to be soldered. Since there is some uncertainty of where the hole is, a large area is cleaned

4. After cleaning the area, you can see that a large crack across the seam has developed. In this whole area we want to add solder.

5. Although the picture is not very clear, we apply FLUX to the area we want to solder. Flux will pull the solder to the metal you want to bond it to. If you don't use flux... the solder will ball up and not stick to the metal.

6. Heat up the area where you applied the flux, then stick your solder end to the area you want to fill. As the solder melts, move it down the seam.

7. If you are not getting the bond you need, get a small screw driver and as the solder is liquid, spread the solder out order the seam. BE CAREFUL NOT to heat to much in one spot. You can make a bigger hole than the one you are trying to fix very easily.

8. After about 15 minutes after the solder has cooled, place your cap back on your radiator and check for leaks. In this case it fixed it fine, so I will clean the surface and apply some touch up paint!

Hope it helps!

WWII Jeep Registry

We log all jeeps by serial number...add yours!

Stay Informed

Subscribe to our e-news. Every month you recieve all the latest info, straight to your inbox.

  • New Article Signup-disabled temporarily
  • Give us Feedback-disabled temporarily
  • Contact me at: