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Flex-a-lite radiators, fans and variable speed controller (VSC) .... review after a few years of use

73k5blazer

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Back in 2007 I bought a 57000 radiator/fan/vsc setup from flex-a-lite. I got my truck running in 2011 and have had issues ever since.

Boy, if I knew what I'd be into on that decision.
The short of it is, flex-a-lite engineering and quality is junk, period.

The long of it is:
Radiators: all leaked at the same exact spot. the 4 corners. It's the classic sign of design or possibly manufacturing defect. I had them leak tested. Now flex-a-lite is happy to send along a new one I will say that about them, their customer service, is good, but what's disturbing is they don't want the old one back. The first one, I thought it was my mounting.. The flex-a-lite radiators have side tanks with heavy thick rails, which is part of the reason I choose them. You can mount things to them and use them to mount the radiator. I had mounted it front face to the rad support at 4 points. I thought mabey it was twisting up on trails and that was causing the leak points. Next one I mounted only two top bolts, basicly hanging. after a few weeks, leaked, same exact spots. where tubes go into side tanks near the 4 corners of the core. The third one I floated with a side mount one bolt and face mount one bolt, both near the center up and down. Leaks, same spot, AND,I didn't even drive it, I started the engine and basically just let it warm up, did that 3 or 4 times. Just heat cycling it, breaks it. Now the leaks were never bad, it wasn't a giant blow hole. And it would only leak after you shut the truck off. It seemed to leak worse in winter than in summer. I was never worried about the radiator coming apart or worried about it driving it long distances on a hot summer day, but it is certainly annoying to have a small puddle of coolant every time you shut the truck off.

Click here to watch the video of one of them being leak tested.
(it's 121mb HD vid, might want to download first, then play)

2012Radiator_Close2.jpg

2007Radiator_FrontClose.jpg

2007Radiator_CloseBack.jpg


VSC controller: this has to be one of the worst possible electrical devices I've ever seen. It certainly does not belong on a vehicle or in any environment that is hot, cold, wet, or vibrates somewhat. 4 controllers. All go bad in various forms. Again, flex-a-lite was happy to send another controller, even if well beyond the 1 year warranty they offer, which is good. But the controller design, is just bad. Two of them simply didn't function if it was above 75degrees out until I mounted a giant heat sink to the back of it but that only increased it's threshold point, it would still cut out if too hot. It's basically a run of the mill board design encapsulated in rubber. Since the rubber doesn't really stick, moisture can sitll get in, and the board itself, is not ruggedized for under hood duty. They tell you you cannot modify the temp probe leads (super thin wire to the probe, they're measuring resistance of), and they're not that long, which forces you to mount the thing under the hood, where this device cannot hack it. I un-encapsulated one, the back had burnt traces and three of the spade terminal for control leads were busted at the solder joints on the back of the board. The turn on and off points seem to vary, not consistent at all. The good, it was variable speed which was nice the fans didn't instantly come on full blast, and it ran the fans for 10s or so after key off which really goes a long way to minimize the radiator heat soak immediately after engine off. But, the unreliability of this board is ... I can't believe it functions anywhere, people who have it must drive their car one day a year or something. I'm extremely anal about my wiring (see this post for a sample on how I do things), everything was properly gauged SXL wire, metri-pak weather connectors where I could use like the high power 10ga wires that lead to the fans, and all wiring in high-temp loom and secured especially near the controller so there was no strain or vibes on the wires entering the controller. Oh, and the override options for full on or full off (never know when you might was to do some fording hehehe) never worked reliably even when new and on the truck just testing out the circuits. Basically the overrides work by grounding a pin on the controller, run that through a switch (or two switches if you want both the full on and full off, or in my case, a three position DPDT switch) and you should be able to throw a switch and ground that pin operating the fans for off or on. The problem was, their logic in that controller fails if it finds any residual voltage on the ground wire your feeding the their controller. since my switch ground lead also served as ground for the illuminated LED within the switch itself, there was like 0.02v or something on that wire and the flex-a-lite controller would sometimes work and sometimes not. I could always get the controller to override by running direct a ground from battery to the pin on the controller. Using that ground wire for anything else that may produce some residual voltage, was problematic for the controller. Working for OEM's and knowing several EE's, when I asked them about this condition, they said, yeah, that controller must be junk. When we design something it has to be able to take some residual voltage in those conditions, up to 3v was a design spec on ground leads into electronic devices. So, I guess, Not their fault explicitly, but it gives you insight into the level of design and testing on the board.

Fans: The one good component of the package. Havn't had any issues with the fans themselves. They pull alot of air. They are 14.5" diam dual fans. They are unimotors, which is a four seasons brand and the same motors you'll find on many production Ford vehicles. My only complaint is they used crappy paint on the mounting bracket, I had to take it apart, sandblast that bracket and re-paint it as it was showing rust after a few rain drives. And they're not 40amps as flex-a-lite advertises. 40amp fuse is mabey a good idea, but when I pulled the spec from uni-motor, those motors are 13.9amps max draw. Meaning 28amps for the pair.

Soutions:
Radiator:
Since they are alum. tubes going into an alum side tank, I am going to try to braze them. I did ask several shops around here, none of them said you can repair an alum. rad. I found some shops online that advertise they do, but nothing near me, I'd have to ship the rad out. Hell, I have three radiators, why not try it myself. I found some youtube videos on how to do it. Put the radiator up on end, wire brush all the tube to tank joints, get some low temp (730degrees) melting alum. brazing rod (Home depot carries, not sure why seems like an odd item, I didn't even know it existed) and use a hand held propane torch and the alum rod will get sucked into all the joints just like solder to copper. I figure, it's worth a shot.

To replace the VSC,
I decided to mess around with my RamJet engine computer. I had already unlocked it and had the tuner software for it. I knew it already has coolant readings and it was capable of doing it, just needed to find the right options in the software to do it. I found if I used the "overheat" flag and check gauges light control pin, it could be done. Overheat condition had a high and low temp set point, and when it reached the high, it grounds the j1-9 "check gauges" pin on the controller, which was unused in the as delivered RamJet setup, and when it reached the low setup, it would unground the j1-9 pin. So, I found the micro-pak 100 terminal GM part number and order a bag of 10 of those, and I setup my fans thorough a relay to ground through that. THe best part is, with the addition of a 2nd relay, I could finally use my full on and full off switch already wired in the dash! The only thing was, I had to uncheck the "reduced RPM mode when engine overheat detected" flag in the software after lowing the overheat threshold considerably. I wired in the two new relays and the new pin out from the engine controller, and works super reliably! I won't have to worry about the GM engine computer overheating or getting cold, or vibrating and breaking solder joints. That's a time tested super rugged board in a super sealed case, a production quality component.
It took a somewhat complicated circuit to do it, but once wired into nice sealed metri-pak 400 relay bases (I used new terminals in the base, no splicing for me). I pillaged this maxi-fuse/relay center from a late 90's Bonneville. It works really well for my needs. New relays are far right and the one on top. The other relays control fuel pump, Ramjet control (came on the harness with the computer), headlights, off-road lights, horn and something else.... grrr....I really need to label these!
WP_20160820_22_44_44_Rich_1_.jpg

WP_20160820_23_12_13_Rich_1_.jpg
 
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bp71k5

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I had almost exact same issues with generic griffin radiators. I'm somewhat convinced that they need to be mounted in such a way that they are free to expand as they heat up. I switched to a aluminum radiator from a guy on eBay and it's been fine.
 

sweetk30

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if the aluminum rad is hot batched = liquid solder/paste then sent threw oven GOOD LUCK on trying to seal it . the more heat you put in to it the more they open up .

if its a good welded tube design then yes you should be able to tig weld it shut .

I would not wana braze it . I would find someone with a tig welder that's good with aluminum .

this is stuff I have read online in other threads / forums .
 

6872xtc

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I had a radiator from Becool...
I made it out of warranty before it started leaking at the tubes. They said to epoxy it.
That lasted more than a month....
 

73k5blazer

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I dunno how these companies are selling this stuff and staying in business. Unless most of their customers are putting them in and using their car once a year to drive to a show 5 miles away on a dry room temperature day
 

diesel4me

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I'd use some Aluma-Seal or Copper-Seal powder ,that stuff has always sealed up leaks in my radiators without clogging them,or the heater core..

I have tried brazing/welding aluminum with those "miracle rods" you see advertised on TV and at swap meets-(same stuff Harbor Freight and Home Depot sells probably,its the same as "Rub-On" aluminum welding rods you can get at welding suppliers..)

-the stuff works great on some things,provided you brush the spot first thoroughly with a stainless steel brush (no others will work,the stuff will bead up and roll off if you use any other wire brush !),and the part to be repaired can be laid horizontally ,you simply cannot get it to flow on vertical surfaces or stick..

I was only able to "weld" up punched holes in soda cans with success,and once I repaired a A/C freon line that rubbed a hole thru,that was about all I could get to work with that crap..

I tried using some to weld a broken "ear" off a mower engine so I could bolt the recoil back on--it snapped right off the minute I tried putting any torque on the bolt,despite it looking like it bonded nicely..

I tried using some to weld seams on an aluminum running board,it broke the first time I put any weight on it..long story short,I think the stuff is a ripoff,and the repairs they show on TV on bellhousings,etc,must be staged,and probably "look" good,but offer no more strength than an aluminum solder...

I think I'd go look for a 4 core OEM brass radiator in salvage yards,at least you can solder those OK...
 

73k5blazer

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if the aluminum rad is hot batched = liquid solder/paste then sent threw oven GOOD LUCK on trying to seal it . the more heat you put in to it the more they open up .

if its a good welded tube design then yes you should be able to tig weld it shut .

I would not wana braze it . I would find someone with a tig welder that's good with aluminum .

this is stuff I have read online in other threads / forums .

Well, since I had 3 of them radiators, I figured, I'd try it. Yeah, that didn't work, at all, a propane torch opened up all the joints quickly with it still 1/2 foot away. What I did find is those radiator cores work very nicely as a grinding base. I keep one around and lay it on my workbench when grinding stuff so if the grinding wheel slips through it only hits the core fins. :grind:
What I did buy was a Howe Aluminum Radiator 342J ($189) , very well built at a great price point. Mounting was a bit of a challenge, had to redo all that, it's more or less mounted like an oem radiator rubber top and bottom and allowed to float.
Haven't had any issue with it in a year and half now with several twist up's on trails and several days driving in 90+ degree weather as well. No problems at all. Finally I'm coolant leak free!!!
HRE-342J_xl.jpg
 

Russell

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I mounted my controller to the inside of the fan shroud where the motors mount. I don't expect it will last overly long and will come up with a better VFD solution later to control them when the controller fails. The Flex-A-Lite's PWM feature is nice, but I am certain I can come up with something that is programmable and more reliable.
 

73k5blazer

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I mounted my controller to the inside of the fan shroud where the motors mount. I don't expect it will last overly long and will come up with a better VFD solution later to control them when the controller fails. The Flex-A-Lite's PWM feature is nice, but I am certain I can come up with something that is programmable and more reliable.
Yeah, I did exactly that, mounted the flex-o-crap controller to the inside of the fan shroud with a big copper heat sink on it as well. Definitely Helped, but still the problem of no fans occurred...mostly with little airflow situations on hotter days (80+), such as slow speed stop and go traffic or trail running, exactly the situations where you need the fans to operate...several times I had to get out and "jump" the big wires on the controller that lead to the actual fan motors directly to battery to get them to operate to prevent overheating.....but my use of the Ramjet controller has been 100% reliable thus far..i just don't get the 'variable' part of the fans anymore...which turns out doesn't really bother me at all!
 

Chevy305

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Knock on wood my $130 Jegs brand universal aluminum radiator continues to hold. Been about 7 or 8 years since i installed it. However my Griffin radiator that I put in my V8 S10 failed pretty quickly. They warrantied it and was fine up until i sold it a few months later. I also had a Griffin fan controller that shit the bed on a hot day in traffic. Had to jump it out with a paper clip.
So in my experience i definitely agree the expensive radiators and fans aren't worth it. I try to use as much OEM stuff as i can.
 

K85 Octane

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Only thing from Griffin I still use is the big relays. On and off, that’s it. I have a switch to turn them on when I’m using the AC. Both my trucks are like this now, running Spectre radiators and Windstar fans.

Both trucks have EFI and a fan relay ground wire, so that makes it a little easier for me.
 

dyeager535

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I try to use as much OEM stuff as i can.

Does anyone make radiators that don't fail anymore?? It doesn't seem like even the big names last. :( I have little faith in my al/plastic auto parts store piece, since the first one failed on install.

We love to complain about OEM prices, but there is a reason that stuff lasts as long as it does. As my recent experience taught me, even OEM plastic/AL radiators are better than the aftermarket radiators made from the same junk.
 

kgblazerfive

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I run a Spal radiator fan controller. Have not any issues with it at all. Uses a real temp sender, the controller is mounted in my cab, still out side but on my "dash".
 
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