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Kafka_Esquire
10-17-2016, 09:14 AM
Time for my Monday morning stumper:

I cannot fully insert the brass connector to the bottom of one of the two holes on my billet aluminum CNC brake reservoir (I used the fittings that came from CNC in the same package). One fitting spins into one hole all the way without much effort, but not the other. It stops at about half way (half the threads showing outside) and will not go further. I tried swapping the fittings, and it seems like the hole is the issue, not the fitting.

Thinking at first that perhaps I got the wrong size fitting, I opened the original FFC chromed reservoir parts that came with the kit to see if I could use one of those "extra" fittings for the CNC. Still would not go in all the way into the CNC (issue with the same hole every time). For giggles, I then tried the FFR fittings on the FFR reservoir. Oddly, each of the fittings fit only halfway into the FFR reservoir and then stop.

Thinking I might have an expansion issue, I put the fittings in the freezer overnight and left the reservoirs in the garage. This morning I tried mating the parts and still nothing. I have measured with calipers, as well as with the gauges in my tap/die set, and the holes and the fittings are all the right size. I cannot see any crud on or in any of the threads, and I also see no evidence of cross-threading.

I'd prefer to minimize my potentially expensive mistakes, so I have a few questions.

Q1: Anybody else have an issue similar to this and if so, how did you address it?
Q2: Can I get away with the existing fitting only going in half way, with or without using DOT- brake fluid tolerate sealer (I think I saw this mentioned in a thread by Bill/2Fast4U)
Q3: Should I just re-tap the hole and get a larger fitting?

Boydster
10-17-2016, 09:33 AM
I'm looking at this picture from CNC's website, and those sure appear to be pipe threaded fittings. They go in until the angled thread tightens up... should not go all the way in.

http://www.cncbrakes.com/images/1483H.jpg

boat737
10-17-2016, 11:07 AM
Those are pipe threads and do not bottom out or go all the way in. 1/8 - 27 NPT. These are 90 degree Pipe to -03AN.

Kafka_Esquire
10-17-2016, 11:24 AM
Thanks folks. So it sounds like the holes (one on the dual CNC and the one on the stock FFR) in which the fittings stick halfway are supposed to stick, and that I need to look again at the other hole on the CNC unit where the fitting spins all the way in without effort...

Best,

Brian

(roller as of yesterday; 306 w/ AOD, 3.55 rear, Nitto G2s 245/45-17 front and 315/35-17 back).

mikeinatlanta
10-17-2016, 12:47 PM
Pipe thread should not go all the way in. Please post pics.

toddhack
10-17-2016, 08:33 PM
I had a similar issue. I ran an 1/8 npt pipe tap in the existing holes and it cleaned up the threads enough for the fittings to seat better.