i just bought a garrett 48/60 t3 and am collecting fittings for the coolent lines and such,and i did some reserch and everywhere i read i found that the coolent holes where tapped for 3/8npt, but the fitting will only go in abut a 1/2 a turn and then start getting really tight to where i have to crank on it with a wrench to get it to turn.iknow these fitting are suposed to tighten up, but damn after like 1-2 turns?im not cross threading it or anything either.

 

nopr your cool
keep wrencjin

 

I ran into this same thing with some old earls fittings before. Make sure the thread hole is clean and isn't causing this. Other than that, just wrench on it until you think it won't leak. The fittings won't always go all the way into the hole, but as long as it doesn't leak, you didn't do it wrong. (My t3 water lines are 3/8. I checked it with one of my 3/8 ls/vtec lines.)

 

thats kinda what i thought(just as long as it didnt leak i was fine),but wanted to make shure.i guess i just expected it to go in atleast a 1/4 of the way, but once again if it dosent leak or fall out(no way it can cause its so damn tight )...oh well

 

use teflon and like they said earlier keep wrenchin

 

You may have a metric center housing. I have one on my T-3. The coolant fitting threads are 16mm. A 3/8 NPT fitting will one go a few turns....then get tight. If you force a 3/8 NPT on it.....it'll cross thread.

One way to check is to get a 16mm bolt and see if that fits.

 

you are correct my turbo takes a m16x1.5. they thread in perfect!! thanks

 

I think that all npt fittings are tapered aren't they? That's why it would get hard to screw in the farther it goes.

 

yes,but these fittings would only go in like a half a turn.so i used a thread guage and the npt fitting was 18 threads per in. and the turbo was 16 threads per in.the m16x1.5 goes in all the way nice and smooth

 

Yeah.........it took me awhile to figure that one out for my set-up........ I had to search all over to find the right 16mm fittings.