Advice Needed! Coolant Leak on 1971 FJ40 after short drive

[talibraza101]

Hello everyone,

Upon delivery, I flushed my South American FJ40 of old coolant and refilled it with Green Zerex Coolant(Zerex™ Original Green - Valvoline™ Global - https://www.valvolineglobal.com/en/zerex-original-green-antifreeze/).

The cruiser has sat idle for several months as I rebuilt its brakes and knuckles, after its first few drives back on the road I’ve noticed coolant foams and leaks out of the overflow tube and onto the pavement after arriving back home (I don’t have an overflow tank). See photos below:

At first I figured it was just a symptom of not driving the thing for a while, so I topped it off with more Green Zerex Coolant. Unfortunately, this has not fixed it. As additional detail: the reservoir fill area is not muddy, and I had definitely topped it off enough with coolant. I had also changed the oil filter and refilled with fresh oil, which seems to have its level perfectly full and the oil looks clean on the dipstick.

What do you guys think is the problem here? Is there something I’m doing wrong/missing? Is it overfilled maybe? Your advice would be super helpful!

Thanks,
T

 

[talibraza101]

Also noticing a tiny leak near the hose:

 

[JohnnyC]

Get an overflow tank

Remove the radiator hose… most likely it’s corrosion on the aluminum most cases if you clean it up and put a new hose on you should be fine if it’s really bad you should replace the upper thermostat inlet

Is that a breather on your valve cover oil filler?

It’s an older cover with that added

The engine looks unique… where is the oil filter located ? Divers side ? But I do not see the oem oil filler tube

Year of truck?

Engine serial number?

 

[talibraza101]

Get an overflow tank

Remove the radiator hose… most likely it’s corrosion on the aluminum most cases if you clean it up and put a new hose on you should be fine if it’s really bad you should replace the upper thermostat inlet

Is that a breather on your valve cover oil filler?

It’s an older cover with that added

The engine looks unique… where is the oil filter located ? Divers side ? But I do not see the oem oil filler tube

Year of truck?

Engine serial number?

Yeah it seems like there are leaks particularly in this area of green Zerex Coolant. I think you’re right on either the hose or inlet being bad.

This is a ‘71 South American 40 that has most of its parts from what seems like a ‘68 40. This is a F engine. Below is another photo of the filter arrangement:

 

[pb4ugo]

Tighten the leaky hose or clean up the connections like JohnnyC mentioned. Because you dont have a coolant reservoir, your over flow tube will push coolant out when it starts getting to operating temp. Eventually the coolant will get to its happy place and stop pushing coolant out. If you continually top it off it will continue the force coolant out. My SBC does the same thing, periodically I will top it off and it usually takes about a quart to top it off. Then it pushes it out. As mentioned, you can add a coolant reservoir. When the engine is hot it will push water into the tank and when it cools down it will suck it back into the rad. Always use distilled water or coolant to fill the rad.

 

[JohnnyC]

Take a pic of the area just before the distributor … your block could be a tad newer than the 71’ your truck is …

F155 side filler was till 71
F155 valve cover filler 72-73
F155 F.5 9/73-12/74

In 71 the filler tube was in front of the distributor… then it got blocked off and the filler was added to the valve cover for 72-72

What’s the engine number?

That’s located on a ledge protruding just forward of the starter on the block

 

[bhsdriller]

Older engines didn't have overflows, as mentioned get one. In the meantime run a long hose off that nipple and put it down by the bottom of the radiator or even extend it a little below so at least it doesn't just go everywhere

Edit: Looks like there's one on now not sure how long it is

 

[talibraza101]

Thank you guys for your guidance as always.

I reseated the radiator hoses. They were a bit loose.

Im gonna look into coolant reservoir ASAP.

As for the engine number, it reads “F 359747”

Thanks

 

[charliemeyer007]

How strong is your coolant? 100% will boil way too low. Most places can run 50/50 anti-freeze/water. There are testers to measure it - use the correct one.

I wedge the antifreeze bottle in behind the head light at my over flow bottle. Drilled hole in cap for hose that reaches near the bottom of the jug. If the radiator cap is in good shape - hot coolant will push pass the cap as it expands into overflow - when the system cools down, the coolant will draw back into the radiator. It will cycle as it heats and cools.

Make sure you don't have an air bubble in the system.

 

[talibraza101]

How strong is your coolant? 100% will boil way too low. Most places can run 50/50 anti-freeze/water. There are testers to measure it - use the correct one.

I wedge the antifreeze bottle in behind the head light at my over flow bottle. Drilled hole in cap for hose that reaches near the bottom of the jug. If the radiator cap is in good shape - hot coolant will push pass the cap as it expands into overflow - when the system cools down, the coolant will draw back into the radiator. It will cycle as it heats and cools.

Make sure you don't have an air bubble in the system.

Thanks for your help, here are the temperature stats for my coolant, should be good I think?

Amazon.com: Zerex Original Green Low Silicate 50/50 Prediluted Ready-to-Use Antifreeze/Coolant 1 GA : Automotive

Buy Zerex Original Green Low Silicate 50/50 Prediluted Ready-to-Use Antifreeze/Coolant 1 GA: Antifreezes & Coolants - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[JohnnyC]

Correct year engine… right at about mid 71’… must have a plug where the filler tube used to be located … somebody improvised and added the filler to the valve cover

 

[charliemeyer007]

Yea that should be good. I have seen folks use the 100% stuff without diluting it. I buy the 100%, 2 gallon and then add 2 gallons of distilled water to fill my nearly 4 gallon coolant capacity.

 

[JohnnyC]

This is were the filler tube would have connected to

Btw not my engine… shipped from online

 

[talibraza101]

To conclude this thread, I installed an overflow tank and retightened all radiator hoses. Looks like the system just needed to be at a sweet spot of coolant quantity to stop it from purging after every drive. Thank you all for your help!