Hi guys! Newbie to this forum. I have a 75 fj40 that has been restored. After driving it and it sets for a few minutes, antifreeze leaks out of the reservoir drain hose. Any ideas on why this happens and possible fixes? Thank you in advance.
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Its getting hot, and/or the radiator cap has failed, and/or it has been overfilled, if you have an infared thermo it doesnt hurt to double check when gauge says normal that its actually at that temp range. I would assume stock motor but looking at front suspension there have been mods.
Have you tried burping it?
Not sure the reservoir has a drain hose. How full is your radiator? If its full to the cap when cold then it will push fluid out to the reservoir tank as it heats up. When you shut off a fully warmed engine it will get hotter for a while before it starts to cool down.
So check all your coolant lines/hoses. Make sure your coolant is like 50/50. What does the temp gauge say when running, should read about mid-scale.
So check all your coolant lines/hoses. Make sure your coolant is like 50/50. What does the temp gauge say when running, should read about mid-scale.
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- #5
Well, the temp gauge currently isn’t working. I had it at the Toyota dealership and had the antifreeze changed a couple months ago. It’s got a 2F motor but I don’t know all the mods.
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- #6
I have not tried this method
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Temp gauge not working at the moment. New 50/50 antifreeze put in a couple months ago.
I understand about the gauge. Does the engine smell hot, does the heater seem to put out really hot air. Got a friend with an IR heat gun $8 and up on Amoron https://www.amazon.com/Thermometer-Backlight-58℉-932℉-50℃-500℃-Temperature/dp/B0BN317X6Z
If this started after you changed the antifreeze, then you likely have a air bubble in the system.
If this started after you changed the antifreeze, then you likely have a air bubble in the system.
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- #9
It doesn’t smell hot at all and the heater actually sucks. Air does not get hot and barely luke warm at best. I didn’t have a lot of drive time before the new antifreeze but I would have noticed a leak. So is burping like my other friend said a potential cure?
When you drain and add coolant to your engine there is a likely chance air pockets will form inside the block when you refill your cooling system. Burping your system will allow the system to pass that air/gas out of your cooling system. You can pick up a burp kit for twenty couple dollars. Go up to the search button and type in “burping” and search the “forum”. It will pull up different threads where this is shown, discussed and demonstrated.
This may not be the culprit in your particular instance but, it’s a handy bit of knowledge for your future reference and the Burp kit is a good inexpensive piece of kit to own…
This may not be the culprit in your particular instance but, it’s a handy bit of knowledge for your future reference and the Burp kit is a good inexpensive piece of kit to own…
Yes. All I ever do is drive up on a steep ramp so the radiator cap is above the heater hose. Open the cap and let the engine run for a while with the heater valve open. When your engine is cool there should be some air space in the radiator (IMHO). With an excellent sealing cap, a good vent hose from the cap to the reservoir that isn't leaking - technically the coolant should push out of the engine when it gets hot and suck back in when it cools down.
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Thank you
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Ok, thank you.
Green Bean
GOLD Star
Welcome to the best forum on the internet. You have a very nice looking rig.. There are many, many very knowledgeable folks here and I've found that they are always very responsive in answering questions (even when mine are usually dumb) and helping me along the path. 
By the way, if you have not already done so, you may wish to get your hands on the Factory Service Manuals (FSM's) for your model year.
By the way, if you have not already done so, you may wish to get your hands on the Factory Service Manuals (FSM's) for your model year.
Some older fj40's had a tube going down the side of the radiator and did not have a catch can. If the dealer didn't drain the block thus doing a proper flush you might have incompatible coolants jelling up, might need to be burped, might have a bad cap, might b overheating, might be normal if it doesn't have a catch can. Picture of your overflow would help. The tube drain goes right down the pass side of the radiator, the catch can style will be on the pass side also. For starters get a cheap manual temp gauge or fix yours, is the wire connected on the sender, back drivers side of the head about 5 " from the firewall. Spade connector on it.
Pop the hood and post a picture of what you speak of. You mention a reservoir, do you mean an expansion tank?I
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- #17
Thanks to so many replies, I think I found the issue. There was too much antifreeze in it. The radiator was full and the expansion tank was full…way past the FULL line.
In the pic, the line that runs towards the left is the one that hangs free under the tank and where the antifreeze has been coming out of.
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- #19
Thank youWelcome to the best forum on the internet. You have a very nice looking rig.. There are many, many very knowledgeable folks here and I've found that they are always very responsive in answering questions (even when mine are usually dumb) and helping me along the path.
rex in bama
SILVER Star
Nice looking rig. Re: taking your rig to the dealership, I’d be very careful- those techs are not gonna be up to speed on working on a 75 carbureted rig. Much better to find a local specialty shop (expertise and price wise) or even a mom and pop mechanic shop - someone with some age on them. Candidly, a dealer ought to be directing you to someone like that.
