Coolant Leak

[CobraChevelle]

So I notice I have a coolant leak under my truck. Not sure where it is coming from yet.

Is the coolant pressure tester from harbor freight any good or should I look at something else? Or better yet, is there a different way of testing for leaks if I cant find it with my flash light? lol

this is the one from HF i was looking at.
http://www.harborfreight.com/radiator-pressure-tester-kit-69258.html

Thank you

 

[Wakefield]

Is it possible to put a special florescent dye into the system and then to (in the dark) shine a special Ultraviolet flashlight around and under the engine/radiator to show dried up tracks that the leaking coolant left? (Hopefully leading back to the leak)

 

[GettinJunkDone]

It depends on your application. I've used the harbor freight kit a few times without any problems and was able to diagnose the problem successfully. Having said that it did not have an adapter for my personal vehicle so be careful, knowing that it doesn't not fit every vehicle. I have a 92 F150 in case you were curious.

 

[Jeeper]

If you don't use it very much, just rent it from the auto parts store. Autozone has the basic old school stant one and Advance has one more like the HF kit with a lot more adapters. I usually use one of those when I need to troubleshoot a coolant leak.

Also when chasing down a leak recently, I rigged up my air compressor hose to tee in the cooling system of a jeep....of course regulated down in pressure. This allowed me to hear the hiss and identify the location. Turned out it was an issue with the water pump. Very handy.

 

[Fender1325]

What vehicle do you have OP? Seems pretty common to be from plastic intake manifolds these days, or cracked radiators.

 

[CobraChevelle]

What vehicle do you have OP? Seems pretty common to be from plastic intake manifolds these days, or cracked radiators.

1996 F250 460v8.

I was wondering if those testers will work with this old truck. This has the old style radiator cap not the screw in style. Its 13lb T13 cap.

this leak is more under the water pump dripping down from the cross member.
My guess is the water pump? maybe frost plug?

I had this happen on my 95 cougar years ago but was leaking more in the front and had to replace the radiator.

 

[Fender1325]

Water pumps do leak when they go bad. Quite likely the case...are you running hot?

 

[Fender1325]

Wipe it up real clean and run the truck, look with a flashlight

 

[CobraChevelle]

running the same temp. Going to check on my lunch break to see how low I am on coolant. Looked under my truck quick before leaving for work today while it was running. Seems to only leak on cool down not while running. In the past some of these are PITA to find so thought about trying a special tool this time if needed.

 

[Fender1325]

Coolant leak on cool down sounds like different materials cooling at different rates. Maybe a bad gasket of sorts.

 

[theoldwizard1]

Buy a Stant Cooling System And Pressure Cap Tester, The "base" model includes adapters for old style radiator opening and caps. The pump is rebuildable ! Amazon - $69.30

Wash down as much of the engine as is reasonable using an engine cleaner and hose. Use compressed air to dry off the engine the best you can. Add UV dye. Pressurize. The tinted safety glasses will help find the leaks.

 

[shockwave]

Check intake manifold where thermostat goes its notorious for leaking

But most likely leaking from weap hole of water pump

And rent the tester from part store unless you will be using more than 2 times a year

 

[four.cycle]

And rent the tester from part store unless you will be using more than 2 times a year

^ this.

options are few:
water pump
thermostat housing
timing cover

the "blow hole" on the water pump generally points down, making it almost impossible to determine exactly where the coolant is leaking.
get a pressure tester, pump it up, and see where it's seeping.
it ain't rocket science, although some of them can be a real SOB to troubleshoot (like my 3.0 V6 Ranger with the leaking timing cover gasket!)

O'Reilly's Auto Parts (and I would imagine probably a couple of the other big chains) will effectively "loan" you the wrench set to remove/reinstall the fan clutch, should that become necessary.
No reason to shell out a ton of money for tools you may only use once in your lifetime.

 

[anndel]

Start with the cheapest repair - check the hoses. Also grab the water pump pulley and jiggle it to see if it's loose. It's supposed to be snug but if there's movement, the bearing could be going or shot. Does is make a grinding or whirring sound when the truck's running? If yes it's the water pump bearing or the impeller. good luck

 

[zcbauer89]

I like the Mityvac tester myself. They have a few kits.

 

[rlitman]

Coolant leak on cool down sounds like different materials cooling at different rates. Maybe a bad gasket of sorts.

Yes, but I'd check the hose clamps first. You don't have any worm gear clamps, right? Those are notorious for this. The factory spring clamps are ok, if the hoses are still ok. Once the hoses age and get "crunchy", maybe that's the issue.

 

[404]

I had one case of factory hose spring clamps not being tight enough. Naturally I mis diagnosed this and spent needless time and money changing the water pump without fixing the problem. In that one case I went to worm gear clamps and got rid of the OEM (Toyota) spring clamps.

 

[dlcwent]

Buy a Stant Cooling System And Pressure Cap Tester, The "base" model includes adapters for old style radiator opening and caps. The pump is rebuildable ! Amazon - $69.30

Wash down as much of the engine as is reasonable using an engine cleaner and hose. Use compressed air to dry off the engine the best you can. Add UV dye. Pressurize. The tinted safety glasses will help find the leaks.

I respect you very much. And you have a wealth of great information here. Always helping people and give great answers to a lot of questions. But I must ask, Why would you want to rebuild a water pump when they are so reasonably priced?

 

[rlitman]

In that one case I went to worm gear clamps and got rid of the OEM (Toyota) spring clamps.

Normal worm gear clamps are fixed diameter. As hoses cool, the tension drops, and they leak.

The solution to this is to use something like a Breeze Constant-Torque clamp. These are spring loaded, so they do not loosen over temperature swings. They also have a liner strip to provide 360 degree clamping (regular worm gear clamps don't clamp well under the saddle; and extrude the hose through the slots).

Your other option is Oetiker clamps, but that's not really the best choice for radiator and heater hoses...

 

[rlitman]

I respect you very much. And you have a wealth of great information here. Always helping people and give great answers to a lot of questions. But I must ask, Why would you want to rebuild a water pump when they are so reasonably priced?

He's talking about rebuilding a pressure tester pump, not a water pump.

 

[dlcwent]

He's talking about rebuilding a pressure tester pump, not a water pump.

He said "the pump is rebuildable"

 

[MrGiggles]

If you don't use it very much, just rent it from the auto parts store. Autozone has the basic old school stant one and Advance has one more like the HF kit with a lot more adapters. I usually use one of those when I need to troubleshoot a coolant leak.

Also when chasing down a leak recently, I rigged up my air compressor hose to tee in the cooling system of a jeep....of course regulated down in pressure. This allowed me to hear the hiss and identify the location. Turned out it was an issue with the water pump. Very handy.

This is what I do when I just need to do a quick test. Turn your regulator down to 14psi, pull off the overflow hose, and pressurize the system with an air nozzle. The cap will act as a check valve to hold pressure.

You'll want to be very vigilant of the pressure you're putting in, since the pressure relief will not be effective.

 

[SantaAna12]

This is what I do when I just need to do a quick test. Turn your regulator down to 14psi, pull off the overflow hose, and pressurize the system with an air nozzle. The cap will act as a check valve to hold pressure.

You'll want to be very vigilant of the pressure you're putting in, since the pressure relief will not be effective.

Niiiiice.