samluke

I run the Mocal cooler under the drivers side fog light, with the oil connections pointing down.

I like the arrangement with it's, neat simple installation. Problem is that its in a fairly vulnerable place just behind the bumper cover. I think I have gone through 7 coolers so far ranging from offroad incidents to leakage over time.

The weak point seems to be the oil connection onto the body of the cooler. when I connect the hoses, I always use the proper wrenches and never put load on the cooler body. I support the pipes and cooler as best I can to take any load off the fittings.

Question is, when they start to leak, can they be fixed?

I have two right now both weeping from the fitting to body joint.

Anyone had any luck repairing them, and if so how. I was going to try and find a good radiator repair shop, but I don't know if I am wasting my time, or should go to a good welding/brazing shop instead. The coolers are not that expensive at approx $150 each, I am just getting tired of throwing money away, and perhaps there's a way to improve this joint?

Willard Bridgham 3

I've lost a couple of coolers, too (in fog light bucket) and I spent a lot of time making the coil location static with reinforcements to no avail. I installed flex connections at the coil and I installed slip fittings at the coil...leaking coils.

Plate and fin coils are made from gum wrappers and their connection points are the same. Unless you can change the front of the car like Jon Milledge does and change the location of the oil cooler, I think we are stuck with replacing coolers.

samluke

Yep, I am pretty much of the same opinion, ie its a fragile design at best, and destined to fail.

I was really hoping that someone had found a way to reliably re-seal them and at least get some more life out of them. It seems a shame, and very frustrating having to throw a $150 cooler out for relatively minor weapage.

YZ250

I have only tried epoxy, which is good enough to get through a weekend, but it eventually leaks again. I think new coolers are the only way to go.

I'm on my third cooler, and this one is holding up nicely. My conclusion is that the coolers are susceptible to vibration, and the recommended installation is very poor. There is no way to get the vibrations downs to the point where a leak won't happen sooner or later (I'm talking track cars).

My solution was to custom build an aluminum bracket that wraps around the cooler and bolted on three sides so that it is firmly held in place by the bracket. The bracket then bolts to the body very securely. The hoses then get their own brackets so that they bolt firmly to the body.

The solution has worked perfectly through two club race weekends and 3-4 DE weekends plus some occasional street driving.

samluke

YZ250, I absolutely agree, and am considering doing something similar. Using the upper two ears alone seems risky. The hose/hose connections need to supported and made stress free as much as possible also, exactly as you describe.

Seems I am destined buy another.

V2Rocket

think itd be possible to modify that one i sent you to work? like removing the old fitting and welding on a new bung for -12an?

samluke

No, that's the problem with these coolers, they are aluminum, which is difficult to work with. If they were copper/brass they would be simple and easy to fix, and also beef up. They are fragile to say the least.

fortysixandtwo

I don't see why they cannot be resoldered together.
If (but from this thread is sounds more like when) my oil cooler developed a leak around the connection point, would probably buy a replacement one. The broken one would go through some repair experiments. I would think with proper chemical / mechanical cleaning, and solder should provide a solid joint.

azmi951

I use a RX7 cooler on my DD and it is very robust. I had a new end tank welded up and brackets welded to it. I get a little dust accumulation but no leaks.

rlm328

My auxiliary oil cooler is located in front of the radiator. I have had the car for 2 years now with absolutely no problems with the auxiliary cooler. I also do not have any over heating problems due to air flow issues.

azmi951

^^^^^^^^^^ That is the same here. No problems cooling with my car in 110 degree heat.

samluke

I amazed that no-one has ever tried to repair one. I would not have been surprised if people had tried and failed or given up. I have ordered yet another new one, and will try and improve the support arrangement. I'll hang on to the others and maybe try and repair them at some point.

azmi951

Rubber mounting is your friend. McMaster has a huge assortment of self adhesive sponge rubber to help isolate vibration and twist from hard mounting.

tyro

Mine is cracked near one of the fittings due to my inattention while tightening.

I'm going to attempt to weld it. Will let you know how it goes..

alxdgr8

Mine has been repaired at a fitting, not sure what with...looks like some sort of foam substance. Doesn't leak or anything.
I'll try and take some pictures of it tonight or tomorrow.