coolant leak/consumption

[papy]

notice today that i had a few drops of coolant on the floor right under the passengers front side. after a quick diagnose i found the the overflow bottle level is way below the cold fill line and the coolant seems to be leaking from the radiator cap.

looks to be slow dripping out from the underside of the cap, however not enough splatter on the frame/lower engine bay or underside of the truck to justify the amount of coolant loss from the overflow tank.

what could be causing this? a bad thermostat?

also are all OEM 289 V8 radiators the same throughout 66-77?

thanks

 

[B RON CO]

Hi, I would just check and clean off the radiator cap. Maybe replace the cap to start.
If you are not overheating it has nothing to do with the thermostat. Is the radiator full? I wouldn't even add coolant right now until the dripping is fixed, unless there is room in the radiator.
Good luck

 

[Rustytruck]

if its dripping tighten up the hose clamps. take a paper towel and dab under the thermostat and also the hole under the water pump neck. to find a wet spot. Does your hose for the coolant recovery bottle go to the bottom of the plastic bottle?

 

[DirtDonk]

...also are all OEM 289 V8 radiators the same throughout 66-77?

No. Most were "the same" but they were not "identical" if that makes sense?
Dimensionally they were all about identical, but slight design and detail changes were a natural thing over the years, including who made any replacements that were used by owners over the years as well.
A brace here, a bracket there, might have been shaped slightly different from an original, and even original OE types might have varied with the vendor during the run of Early Broncos.

The '66 and '67 and perhaps some '68's(?) were used with a Surge Tank that was a separate tank hanging there in space between the radiator and engine. The radiator fill cap was on this tank and the radiators themselves did not have a filler neck and cap.
In '68/'69 the cap went to the radiator tank and they were all about the same through '72. Same location, same height approximately, same radiator cap used.
In '73 the same basic shape and size was retained, but a trans cooler was added through '77. Whether the fitting sizes, locations or type changed in that time I do not know.

The overflow tube varies slightly, but most are like yours if I'm not mistaken. At least until '73 when they added the recovery tank on the wheel well. Prior to late '72 early '73 model years, the overflow just emptied on to the ground.
Some overflow fittings at the neck were just hose barb/nipples, while most were a full tube running down the side like yours.

So yes, they're the same. But no, they're not the same.
Clear as mud?%);D

Paul

 

[DirtDonk]

Oh, and look/feel underneath the water pump to see if fluid is coming out of the weep hole. If it is, then you're going to be replacing your water pump sooner rather than later.
It does not seem to matter what age anymore. Some pumps just have their seals and bearings fail a lot earlier than in the old days when you could count on the pump lasting at least 60,000 miles or so. But it does still depend on how tight your belts are, and how diligent you are at changing your coolant every two years like recommended.

If you're lucky, it's only the lower radiator hose weeping and tightening the screws a little bit like Rustytruck said you can get a little more life out of them.

Paul

 

[papy]

Hi, I would just check and clean off the radiator cap. Maybe replace the cap to start.
If you are not overheating it has nothing to do with the thermostat. Is the radiator full? I wouldn't even add coolant right now until the dripping is fixed, unless there is room in the radiator.
Good luck

the cap is brand new as of April when the bronco was back on the road. might be a faulty cap - who knows with the poor quality of parts being produced these days...

i will check the fluid level in the radiator tonight and see where the level is.

if its dripping tighten up the hose clamps. take a paper towel and dab under the thermostat and also the hole under the water pump neck. to find a wet spot. Does your hose for the coolant recovery bottle go to the bottom of the plastic bottle?

Oh, and look/feel underneath the water pump to see if fluid is coming out of the weep hole. If it is, then you're going to be replacing your water pump sooner rather than later.
It does not seem to matter what age anymore. Some pumps just have their seals and bearings fail a lot earlier than in the old days when you could count on the pump lasting at least 60,000 miles or so. But it does still depend on how tight your belts are, and how diligent you are at changing your coolant every two years like recommended.

If you're lucky, it's only the lower radiator hose weeping and tightening the screws a little bit like Rustytruck said you can get a little more life out of them.

Paul

no leaks from any of the connections or at the water pump. only leak is from the underside of the radiator cap as shown in the pic

 

[papy]

No. Most were "the same" but they were not "identical" if that makes sense?
Dimensionally they were all about identical, but slight design and detail changes were a natural thing over the years, including who made any replacements that were used by owners over the years as well.
A brace here, a bracket there, might have been shaped slightly different from an original, and even original OE types might have varied with the vendor during the run of Early Broncos.

The '66 and '67 and perhaps some '68's(?) were used with a Surge Tank that was a separate tank hanging there in space between the radiator and engine. The radiator fill cap was on this tank and the radiators themselves did not have a filler neck and cap.
In '68/'69 the cap went to the radiator tank and they were all about the same through '72. Same location, same height approximately, same radiator cap used.
In '73 the same basic shape and size was retained, but a trans cooler was added through '77. Whether the fitting sizes, locations or type changed in that time I do not know.

The overflow tube varies slightly, but most are like yours if I'm not mistaken. At least until '73 when they added the recovery tank on the wheel well. Prior to late '72 early '73 model years, the overflow just emptied on to the ground.
Some overflow fittings at the neck were just hose barb/nipples, while most were a full tube running down the side like yours.

So yes, they're the same. But no, they're not the same.
Clear as mud?%);D

Paul

haha i knew it wasn't gonna be a simple " yes they are all the same" lol

how about the radiator caps - all the same?

 

[DirtDonk]

Well then I'd agree with a new cap. But be sure to inspect the surface of the filler neck, because it's not impossible for that to have been damaged at some point.
With new parts these days I almost am at the point of automatically suspecting any new part of being defective right out of the box!

I know it's not that bad, or we'd have had a lot more returns on the stuff we sell. But you hear about it so often on the forums these days that it's impossible to ignore the possibility anymore.

Paul

 

[papy]

Well then I'd agree with a new cap. But be sure to inspect the surface of the filler neck, because it's not impossible for that to have been damaged at some point.
With new parts these days I almost am at the point of automatically suspecting any new part of being defective right out of the box!

I know it's not that bad, or we'd have had a lot more returns on the stuff we sell. But you hear about it so often on the forums these days that it's impossible to ignore the possibility anymore.

Paul

most likely the culprit being the cap. good call on checking the neck for imperfections, nicks and what not

thanks

 

[Rustytruck]

still should not have leaked on the floor. the cap has too seals the lower inside the neck and the upper which seals the top rim. the lower part have a vacuum relief valve with a seal too. radiator should be filled to the top in a closed recovery system. coolant when it gets hot is pushed by the lower cap seal and expands into the jug ass the system cools it sucks back the coolant past the little disc valve on the bottom of the cap. if the coolant was left low in the radiator the cycling will steal the water from the recovery bottle and you have to add water to the cold full level. if it is leaking on the floor from the cap there is a problem with the top seal with the cap as any over pressure should push out the recovery bottle. check that the overflow tube is open and goes all the way down to the bottom of the recovery bottle.

 

[Slowleak]

most likely the culprit being the cap. good call on checking the neck for imperfections, nicks and what not

thanks

I had one with a nick in the lip when I got it back from the radiator shop. A little JB Weld and a piece of sandpaper fixed it right up….


Sent from my iPad using Tapatalk

 

[BUCKWILD]

I had a 289 it used coolant regularly and never had a cooling problem. I never found a problem with it ( 3 intake manifolds) believe it to have been a cracked head. Whelled the rig a lot and never got over 230, didnt wort about it. 240 wouldnt bother me for that fact

 

[papy]

I had one with a nick in the lip when I got it back from the radiator shop. A little JB Weld and a piece of sandpaper fixed it right up….


Sent from my iPad using Tapatalk

so after inspecting the radiator cap and the rim of the radiator filler neck it seems like i had some paint on the rim that kinda softened up and turned into a gummy gunk. i cleaned the rad cap, and the filler neck rim. the fluid that was low in the overflow tank is now in the rad as it was quit full when i opened it up this morning. i refilled the over flow to the cold fill line.
guess we will see what happens...

on another but same note, i noticed that the upper rad hose was and has been collapsing (vacuum) over the last couple times i looked under the hood when the engine was completely cold. i am wondering what could be causing the hose to collapse? when i open the rad cap (cold) the collapsed rad hose decompresses

could all this be related? maybe its more than the rad cap i originally thought?

JP

 

[Slowleak]

Sounds like a bad cap. When the engine and radiator cool, coolant should be pulled from the reserve tank back into the radiator. If the cap is faulty, and coolant cannot return, then the resulting vacuum will cause the hose to collapse. Make sure the hose to the reserve tank is not clogged also.

 

[73azbronco]

Best way to diagnose coolant leaks, use a free test kit from parts store.

 

[papy]

Sounds like a bad cap. When the engine and radiator cool, coolant should be pulled from the reserve tank back into the radiator. If the cap is faulty, and coolant cannot return, then the resulting vacuum will cause the hose to collapse. Make sure the hose to the reserve tank is not clogged also.

Turns out the hardline for the reserve hose on the radiator was clogged up. Coat hanger auger did the job! I'm sure the problem is now fixed guess we'll see later on...

Cheers

 

[Slowleak]

Turns out the hardline for the reserve hose on the radiator was clogged up. Coat hanger auger did the job! I'm sure the problem is now fixed guess we'll see later on...

Cheers

That’s good news. A coat-hanger can really be your friend sometimes….