Ford GPW Jeep #208102 with Willys Trailer ready for the Corona, CA 4th of July Parade4th of July Parade and Overheating Issues

For the second year in a row, I was able to participate in the Corona, CA 4th of July Parade… and this time I got to tow a WW2 Jeep Trailer (first time)! But, as I drove home, the Jeep started to overheat, so I do some digging into the issue.

It’s been a few weeks since the last full update, but finally, some things to post about! I hope everyone had a great 4th of July! So let’s dive in.

Last year I was invited to participate in the Corona, CA Independence Day parade on historic Main Street. It was a lot of fun, so I was looking forward to being in it this year again! After cleaning up the Jeep the previous afternoon, bright and early I was on my way to the heart of Corona.

I arrived at the pre-staging ground to connect with others from the Historical Unit of Southern California Sitting out in front of the house was a WW2 trailer, decked out with some buntings for the parade!

It turned out I was going to be the only Jeep in the parade, as the other Jeep was down for some repairs. So, that meant I’d be towing the trailer!

This is the very first time I’ve ever towed anything with the Jeep since the restoration, which was exciting to say the least. So it’s the first time the pintle hook would be actually used!

It’s an authentic WW2 Willys trailer, which is pretty awesome. I’ve been hunting for a trailer to purchase for a while now, so it was great to ‘test’ it all out to see how it would work and actually drive with a trailer attached.

Here’s the Jeep/Trailer at the parade start in the vehicle staging area. It wasn’t the easiest backing into the spot with the trailer, and we ended up having to unhook the trailer and move it manually.

Once again, I placed my Ammo Crate Radio on the hood with the WW2 intercom speaker. It was hooked up to my phone via Bluetooth, blasting 1940s swing music. You can see how it was built here: https://1944gpw.warbirdphotos.us/blog/ammo-crate-radio-gpw-display-sign-flea-market-finds/

A nice lineup of cars (and more on the other side of me)

Representing the American Legion Post 216 of Corona were three WW2 vehicles, not with us sadly. One was this gorgeous Ford Staff Car.

They also had a Chevrolet G506

And a Dodge WC truck!

The next few photos were taking by my girlfriend, who was walking down the route. Here we are heading down the street. We had a large gap in front and behind us as they waited a long time to release us from the staging area, and then the group behind us was also late to come out (and were walking slowly).

I had two 9th Infantry Division reenactors walking alongside my Jeep, and a gal in the trailer.

The parade route is actually down hill, and last year I overheated the clutch working the engine during the parade (which I tried to avoid)… so this year I just put it in neutral and let the Jeep coast down hill, only using the brakes. That worked perfectly. Never once was I too slow or needed to engage the engine until the very end.

One thing I did notice is that the brakes were a little more squeaky than usual, which I think was due to the added weight of the trailer.

Everyone had smiles, and when I would honk the horn, it would make people cheer. So it was fun to be the main parade vehicle for the group!

After the parade, we parked around back of the house and I was able to get some shots of my Jeep with the trailer.

After towing it around, it makes me really want to find an actual WW2 one and have that available for events! Overall it was a fun event, and I hope to get more Jeeps to join us next year! I would love a small caravan! If you have a Jeep in the Corona/Chino/NorCo area, message me!

So the real issues started on the drive home. After a relatively cool and overcast first half of the year (pictured here), late June into July the SoCal heat has finally started to catch up with us. This 4th of July was a good 97ish degrees and dry. I knew the Jeep would have an issue with the heat, and I feared driving home as it was mid-day. It doesn’t help that Corona has a lot of steep hills to go up.

The day before the parade, I had made sure to top off the coolant, to make sure it was full. I knew it would regulate itself over the day and expel it out the radiator relief tube, so I wasn’t too worried about making sure it was full (which you’ll know is full when you can see the top of the liquid in the radiator to the inside left, just before it peaks over the side to the area under the cap).

I kept a careful eye on the temperature gauge the short, but hilly, drive home. It was hot, there was no wind, and I chose a new route that had the large hill I have to take broken up into a few smaller ones. After a short amount of time, the temp was already at 180. It started to creep over into 190/195, but a quick change to 1st gear after a stop sign, and the temp would go back to 180 or 175. I have a 160 thermostat, so that should be normal. Soon, though, it started to creep up into 200, then go back to 180/185 in 1st. And then after one hill, it jumped to 205. Then 210. Yikes. Putting it into 1st gear only would take it down to 198. Then it hit 215 during a longer spell with no stops, so I pulled over and went back into 1st. That took it back to 198 where it fluctuated between 198 and 201. I stayed in 1st gear most of the way home so it wouldn’t overheat. For those that don’t know, 220/225 is pretty much boiling for the Jeep.

(this is just a photo of the gauge for something visual) It wasn’t a fun drive at all. And for some time now, overheating has been an issue. Even on cold days of winter when it was a high upper 50s, I could easily get the Jeep to 190 when driving around the neighborhood.

I’ve been strategic with my driving because of this issue, not driving during hot parts of the day, or having to modify how I drive to keep it cool. But it shouldn’t be doing this. My radiator is original, and it hasn’t been re-cored, but I have worked on it. The engine has been flushed as well. In fact, let’s take a look at what all I’ve done over the last 3 years to help with the overheating.

From the start, I went with a 160 degree F thermostat since I live in a hot part of the world. In this area of SoCal, it can get up to 115 or more with super dry scorching heat. So I’ve had a newer style thermostat for that reason.

The original radiator cap on the Jeep was not an original WW2 one. I have since gotten a correct 4 pounds of pressure F marked cap. The radiator, as mentioned, is original to my Jeep. It appears to have been worked on at a shop in LA sometime in the late 40s or 50s.

Here’s how you can tell the pressure rating on the cap, the 4 next tot he Ford F stamp.

Back when I first got the Jeep running during the restoration, this is how the cap looked. Lots of muddy mess in the cooling system.

That’s what started me on a flush crusade. It started with PEAK Radiator cleaner/flush.

It did wonders in breaking up the crude in the system, as you can see. Gross. After each flush, I would ‘flush’ the whole system out with water.

After the PEAK, I ended up using CLR (recommended on G503) and did a week long flush with that in the system.

Each time, things would get better and better. As you can see, here’s a big difference inside the block from before and after two flushes.

After draining the flush liquid out (not into the gutters!), I would then rinse out the flush with water.

Eventually, after 3 flushes over a 3 week span (broken up by a few weeks in between), the water started to come out clear.

Soon there was no gunk in my system showing up on the radiator cap.

This was shot not that long ago, and almost a year of running the Jeep without cleaning the cap. Little bits of minor stuff, but overall pretty good.

As for the radiator, I did three flushes on it with high-powered water. I cleaned it out each time until there was not a single debris or muddy thing in it. But, I can’t see inside the radiator, so it’s possible with all the gunk that since the beginning when I got the Jeep, one of the cores has been blocked causing the coolant not to fully cool. I’ve been reluctant to have anything done to the radiator because of the costs. Just about any place here in SoCal that could recore the radiator wants $900-$1000 to do so. That’s just not worth it, especially since a high-end reproduction (not aluminum) is about $575. So I’ve held off trying to see if I can use my original as much as I can.

And some very small pinhole leaks have started on the radiator, nothing that should affect pressure (like this one here on the neck, this was after a 40 minutes drive, so not bad). So the time has come for me to really figure out what’s going on here. Is it a bad radiator? A bad thermostat? blockage in the engine block? It can’t be the water pump as that’s brand new and the one before it had the same issue.

So this weekend, it’s going to be very hot again. I’m going to remove the thermostat in the elbow and try running the Jeep through the paces with not thermostat. If the Jeep stays cool, then either 1) I have a bad thermostat, or 2) I need to get an original bellows type of thermostat that opens much sooner than 160. I’ve also heard of people getting 145 degree thermostats as well to help.

But beyond that, I’m also getting a infrared thermometer this weekend that I’m going to test the temperatures in the input/output tubes of the radiator. One should be pretty significantly cooler than the other. If both are hot and I can hear liquid movement in both, then I know the radiator is to blame and will probably need to be replaced. If there is a pretty big difference in the temperatures, then I might have to really focus on the block. It could be a faulty temperature gauge as well, but I’m not thinking that’s the issue here. So I’ll report in my next update my findings and decision moving forward.

So, that’s it for this week! A fun 4th of July parade, but another task at hand. Getting the Jeep to a level where I can drive it in this 95-100 degree heat without worrying about it overheating so quickly would make my drives so much more enjoyable. We’ll see what happens!
Till the next update…