My just installed dual mocal 19row oil cooler kit is leaking at the first cooler hot side connection. How do i fix it? It is the only leak and I took off the hose, put it back on and it still leaks. Should I tighten it more? I've heard it's bad to overtighten -AN fittings... HELP!?

 

Hydrocarbon resistant Teflon?

This stuff: http://www.imacsystems.com/teflon_tape_thread.htm

Available at home depot.

 

AN compression fittings should not require any type of tape or sealant, but if you get persistent leaks you can try it. Take a look at the threads, they may be galled or have debris in them.

 

i've also seen improperly assembled -an fitting/braided line assemblies where the -an line was not inserted fully into the -an fitting prior to assembly completion. this can lead to leaking from the area where the braided line is inserted into the -an fitting.

 

You should not use any kind of tape with AN fittings. They seal is created by the end of the fitting not the threaded portion. The tape could potentially prevent the fittings from screwing all the way together.

What kind of fittings are you using? Earl's and Mocal both have assembly instructions available online.

 

Is it leaking at the junction of the two -AN fittings or where the ss hose inserts into the fitting?

 

Is it possible he means the threads going into the mocal cooler?

 

You need to give us more exact information about where it's leaking from....

The first time I started up the car with aftermarket coolers, I had a few slow leaks too at the fittings, as I was also worried about overtightening. Cranking on them a little more (with AN wrenches) solved the problem. Also make sure you correctly installed the fittings on the oil coolers and didn't mess up the o-rings.

 

there's no o-rings in my kit... it's a cwr that came with all the lines assembled.

it's leaking through the cooler threads, it comes out from the edge of the hose to cooler connection. When I tightened more with the engine running it leaked more!

oh and i dont have an -an wrench, im just using a regular adjustable wrench and everything but that fitting is ok

 

It's not uncommon for the threaded inserts where the AN fittings attach in the Mocal coolers to crack (I assume it was a used kit). They're not held in well.

I've got one that cracked and was replaced with a 19-row Earls, because they're a bit tougher.

 

The coolers ship with the fittings unassembled (at least Earls do), when you attach the fitting to the cooler, there is an o-ring that goes in there. Any way, Peter is probably right about the source of the leak.

 

i'll check but the kit was new when I bought it, never installed before. unless I broke the cooler fitting by overtightening...?

my camera broke so I drew a picture, the oil seeps out from the red areas

 

I would get two wrenches... one to hold the hex-shape portion of the fitting on the cooler, so you don't rip it off, and then the other to turn the AN fitting, and crank it on there a little harder.

 

Yep, that is the correct way to tighten any of those fittings in the kit.