LMTV Coolant Leak Diagnosis Suggestions

[dbeasty]

I have developed a relatively small coolant leak.

I have located some light fluid slow drip on the radiator bottom on one side, but do not know exactly where exactly is the source of the leak.

Any suggestions on how to track this leak?
Any good pressure test tools that fit LMTV fill cap and what pressure should I pump it up , or shall I get dye so I have easier time to locate it?

 

[Reworked LMTV]

You can rent a a cooling system pressurizer from auto zone or another part from hell store. Should have A- dapters. DO NOT exceed the manufacture's PSI rating for the cooling system, or you may be doing a head gasket in your future. You can also use a dye kit and UV flashlight.

 

[MrMikey4026]

Has to be heater hoses/core/valve, leaking down from above or radiator hose/radiator.

 

[coachgeo]

Like MrMikey suggest...... get pressure tester AND

 

[dbeasty]

I did look at for a while and it really "seems" the small dripping leak is dripping from front bottom radiator tub, did check all the hoses, radiator sides nothing... The pressure tester is on the way, any idea how much PSI I should apply?
Almost tempted to use some kind of radiator coolant sealant solutiuon..but not sure what would be long term drawbacks.

 

[Kbarnes0]

I did look at for a while and it really "seems" the small dripping leak is dripping from front bottom radiator tub, did check all the hoses, radiator sides nothing... The pressure tester is on the way, any idea how much PSI I should apply?
Almost tempted to use some kind of radiator coolant sealant solutiuon..but not sure what would be long term drawbacks.

I wouldn't run a leak stop. If you just want to (try) fix the leak without concern of other items in the system being reduced performance or problems you can do that. I would only use it on a rig that I don't care about. Half the time the result is you are diving back in to fix it the correct way. Then you see what that stuff does.

With your tester you should be able to see the location. Look at your radiator cap and see what the pressure rating is. I believe mine is 16lbs.

 

[Reworked LMTV]

I think I did a conservative 13# pressure.

 

[dbeasty]

I did put the fluorescent tie in the coolant, also did pressure the system to 13 psi. The slow drip up front from above the radiator pan did intensify to more , but did not see any hose leaks or streak on radiator or something streaming out..

I suspect the next step might be to take out the radiator, which might be bit of an ordeal.

 

[ckouba]

Rad removal was nothing overwhelming. It's large and awkward but the process is straightforward. I was nervous going into it but if you're into working on this stuff, it should be no problem.

 

[dbeasty]

I took it to the shop and they confirmed its the radiator. Now need to get a new one or fix the old one.. The old one look visually really good, so not sure why it has the leak around the pan...

 

[coachgeo]

I took it to the shop and they confirmed its the radiator. Now need to get a new one or fix the old one.. The old one look visually really good, so not sure why it has the leak around the pan...

IMHO I would fix the one you have. Reason being it will get properly cleaned and then fixed..... which will make it better than anything used you buy unless they had to bypass passages in the core being fixed.

You might consider an second opinion too. Is the shop one that deals with radiators for big rigs, heavy offroad equipment etc... IMHO that is all I would trust for this application.

 

[dbeasty]

Good point; its a large shop dedicated for the big rigs only and they confirmed what I have detected. They always treated me well and respected the fact that this is a hobby . Depends on estimate, but very likely will be doing the work myself. Their thinking is in case the radiator is not repairable, you do not want to to be stuck, hence having sourced a new one is a good idea.

But yes want to take the repair route unless some really good new old stack reasonably priced radiator pops up and even then would like to take the repair route for the one I have and keep it as backup.

 

[dbeasty]

Apparently it turns out the radiator shop tried to repair my radiator and sealed the 10 inch crack in the base, but that did not help the result.
The quote for proper fix was over 2.6 where they would replace the core..

Hence I am looking ideally for a new radiator.

Any ideas where to source new LMTV 1078 A1 radiator from?

 

[coachgeo]

looking for a new to you radiator...... or a "new" (NOS) radiator. huge difference in answer you would get

 

[fuzzytoaster]

Not to sale pitch here but I have a close to new takeout A1 radiator from a M1078A1. Odometer showed 1800 miles on it. I too have been looking for a "NOS" radiator unit as a spare but haven't seen one. Figured I'd throw it out there to help.

 

[dbeasty]

Thanks, I think at this moment I take the best radiator reasonably priced I can get, since seems like the new or NOS ones are not available.

I did try to reach via message to fuzzy toaster..,

 

[dbeasty]

To close on that thread, got a really nice used radiator from another A1 by fuzzytoaster, passed the pressure test and is installed and working nicely...