Pressure testing aluminum radiator?

[StolenFox]

So I had to modify the filler neck position on my radiator and I'd like to check it for leaks. I'd like to pump it up with air and soap test it but I'm nervous as I've got a ton of time in modifying this things for LSx BMW duty. I was thinking maybe 5 psi because if memory serves me its a 4:1 ratio of air vs water so 5 psi of air should approximate 20 psi of water.

Any ideas?

S.F.

 

[readhead]

One pound is all you need. If there is a hole you will find it quick.

 

[rlitman]

Pressure is pressure. No idea why you think there is a ratio or what ****** you pulled that number out of.

What pressure is that system designed for? Why not fill it with water to the design pressure (what is the pressure rating of the cap) and see if it drips? I don't see the point in soap bubbles for this application.

 

[kkroger]

Typical pressure in a closed system is rated by the pressure relief cap, typically 15-20 PSI, if your radiator FAILS catastrophically at that pressure you didn't want it anyway... Go to Harbor Freight and get a radiator pressure test kit... Selection of adapter caps and a little hand pump with a gauge...

 

[Gui961]

we test cooling system at 30 psi all the time . normal operating pressure is 10-20psi...

 

[StolenFox]

No idea why you think there is a ratio or what ****** you pulled that number out of.

20 years in the Fire Sprinkler industry where the "pressure ratio" was often cited for pressure testing Dry Pipe systems using air instead of hydrostatically. I think the issue was related to the danger of having 100's of gallons of system capacity pressured to 210lbs and suffering catastrophic failure and pressure release. I "think" ASME B31.1 made reference to a pressure ratio for pipe testing as well but can't guarantee it.

In any event, thank you for the eloquent way you shot holes right through my question.

Thanks to all who responded.

S.F.

 

[raddksn]

20 years in the Fire Sprinkler industry where the "pressure ratio" was often cited for pressure testing Dry Pipe systems using air instead of hydrostatically. I think the issue was related to the danger of having 100's of gallons of system capacity pressured to 210lbs and suffering catastrophic failure and pressure release. I "think" ASME B31.1 made reference to a pressure ratio for pipe testing as well but can't guarantee it.

In any event, thank you for the eloquent way you shot holes right through my question.

Thanks to all who responded.

S.F.

I see what you did there! nice!

 

[alwaysFlOoReD]

I moved the rad to the back of my race truck and wanted a simple, quick way to find the inevitable leaks without wasting time with water or antifreeze lose. i drilled a hole in the custom made thermostat housing and installed a tire valve. The valves are rated to 65psi. I've used one before for 6 years with no problems. Then at the rad cap end I use a cheap Princess Auto [Canadian HF] pressure gauge to monitor pressure. It takes ten or fifteen seconds to pressure up the system and like others have said, if you have catastrophic failure, you didn't want to run the rad anyway.

 

[raddksn]

I moved the rad to the back of my race truck and wanted a simple, quick way to find the inevitable leaks without wasting time with water or antifreeze lose. i drilled a hole in the custom made thermostat housing and installed a tire valve. The valves are rated to 65psi. I've used one before for 6 years with no problems. Then at the rad cap end I use a cheap Princess Auto [Canadian HF] pressure gauge to monitor pressure. It takes ten or fifteen seconds to pressure up the system and like others have said, if you have catastrophic failure, you didn't want to run the rad anyway.

brilliant !!!

 

[Superbec]

20 years in the Fire Sprinkler...
In any event, thank you for the eloquent way you shot holes right through my question.

Thanks to all who responded.

S.F.

hey .. what about the end craters you left all over the welds... is that sprinkler technology know-how translated into welding ???

 

[onkyo]

couldn't you use vacuum to do the same thing?

 

[StolenFox]

hey .. what about the end craters you left all over the welds... is that sprinkler technology know-how translated into welding ???

Thanks for pointing out that I do in fact **** a tig welding aluminum. I'm self taught and is approx the 10th time I've put arc to recycled beer cans. My machine is a Miller Econotig which has no waveform adjustments that would be beneficial to a newbie with limited skill. I did two passes here, one with filler that looked more tradition "stacked dimes" and then a hotter pass because I was concerned with leakage.

For what it's worth, everything to the right of the inlet tube is factory weld, craters and all. Looks like a spool gun was used.

Given my lack of skill I will be pleased if it works well for and does it for a long time. Ill leave the weld **** to the pros. That said, I do ok with 304ss and mild steel....

S.F.

 

[sberry]

There is nothing wrong with that welding for this job.

 

[rsanter]

Use the expanding rubber plugs for the inlet/outlet
Fill with water then use a cooling system pressure tester to pressurize the system.
Easy

Bob

 

[Griff93]

They make some really nice caps that fit over the hose ****** for pressure testing. They come in a big range of sizes.

Those welds should work fine as long as you don't have a pin hole. Adding some more filler before coming all the way off the pedal is a good idea.

 

[StolenFox]

Well it passed 20psi of air with no leaks so it should be good to go. Funny to think that with a little modification that a radiator made for 60's GM full size cars can fit a 2000 BMW.

Thank you to all who replied.

S.F.

 

[Griff93]

I see the odd radiator and the empty engine bay, motor swap?

 

[StolenFox]

I see the odd radiator and the empty engine bay, motor swap?

Correct you are. In the process of swapping a 6.0L LSx in my 2000 BMW 528i. You can see a peak of it in the 2nd to last picture.

S.F.

 

[raddksn]

What's the wall thickness on the rad tank?

 

[Superbec]

There is nothing wrong with that welding for this job.

other than cold on the right and overcooked on the left side... inconsistency is not that big of a problem but the end craters are.

It sure could be good for a thousand years though

now I'm just kidding, a bit of grinding bit of paint makes a weldor what he aint

what bmw is that? e39?

 

[StolenFox]

What's the wall thickness on the rad tank?

Calibrated eyeball says 1/8", didn't measure as I was too busy freaking out over the giant hole I cut in the end tank and praying that I could successfully weld the fill neck assembly on....

other than cold on the right and overcooked on the left side... inconsistency is not that big of a problem but the end craters are.

It sure could be good for a thousand years though

now I'm just kidding, a bit of grinding bit of paint makes a weldor what he aint

what bmw is that? e39?

Over cooked on the filler neck assembly and its attaching welds to the end tank are mine. Everything to the right of the inlet tube with the yellow cap are factory welds on the Speedway Motors radiator. I did a hot cover fusion pass (no filler) after welding it on because I was afraid of leakage. The first pass looked more traditional.

Yes, it's an E39.

S.F.

 

[Superbec]

Everything to the fight of the inlet tube with the yellow cap are factory welds on the Speedway Motors radiator.

don't get me started on this... scary amount of weld failures on factory jobs done by robots also .

I did a hot cover fusion pass (no filler) after welding it on because I was afraid of leakage. The first pass looked more traditional.

Yes, it's an E39.

S.F.

that's not a good thing to do on aluminium, it may be on steel or stainless but never on aluminium

 

[sberry]

I weld fittings to .050 up to 6 inch and 150# pressure, this radiator aint squat crater or not.