GRM way to fix this Miata Fitting: Grassroots Motorsports forum: Grassroots Motorsports Magazine

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July 1, 2011 3:55 p.m. flexi New Reader
Trying to button up a timing belt job. Everything is installed, just checked the oil to see if I had changed it. (You really don't know want to know how long this timing belt job from Hades has been going on.) Oil is good.

Now time for coolant. Being cautious, I pour in water. Of course it starts pissing out. It is coming out of the L shaped 5 or 6mm diam tubing coming from the coolant manifold. The clamp is tight. Hose is brand new. Could be the funky solder like joint making the right angle that is leaking, or a crack along the bottom of the L pipe. (Hard to tell, even with inspection mirror.) This fitting connects the coolant manifold to the thermostat housing.

What are the options?
1. New coolant manifold - takes time - and money... At this point, I only object to the time. Summer in New Hampshire is so short, and I've made this job so long.
2. Cap both ends, hope for best...
3. Cut off L, make crazy coolant line going the wrong way around the belts?
4. Cut off L, jury rig an elbow into coolant manifold?
5. Enter something realistic here... I'm really looking for help folks. Cram flexible tubing around leaky L, clamp and hope for best? I have some silicon hose that might make it around the L joint.
What would GRM'rs do?
July 1, 2011 4:24 p.m. PseudoSport Reader

Can you drill out the fitting and tap the hole for pipe thread? Then you can install either a straight or 90 degree brass hose fitting
July 1, 2011 4:42 p.m. Keith SuperDork

I'd determine what exactly was leaking, and fix it in a way I wouldn't be ashamed to show to other people. Good diagnosis often saves a bunch of time.

As for a fix, if it's a leaky joint where one pipe joins another, some JB Weld would probably work well. Greg's NPT solution is a good one as well.
July 1, 2011 8:54 p.m. flexi New Reader

In reply to Keith: The L-shaped nipple on the water pump inlet (B61P-15-160) has a split along the bottom. I "fixed" it using a short piece of rubber tubing to surround the split. A wide hose clamp on top of it is holding it. It held pressure, but it is not a permanent solution. Not ashamed of the solution either. JB Weld might improve the goodness a bit more (along with my clamp).

Seeing as this is a skinny tube sticking out the water pump inlet, what size pipe thread would fit? I'd bet 1/8 NPT would be huge (~10 mm hole) compared to the casting. That leaves 1/16 NPT.

Maybe I can find a water pump inlet at a junk yard? I've got a 1994. All 1.8 NA's the same?
July 2, 2011 8:18 a.m. spritedriver28 New Reader

Ask the guys at Flyin' Miata. They have saved me from myself (repeatadely) by having obscure used parts in stock that the dealer would have killed me with price.
July 2, 2011 10:39 a.m. Keith SuperDork

Yes, all the non-turbo 1.8 parts are the same. I'm pretty sure they're the same for the 1.6 cars as well. We have a pile of them at FM.