Compression fittings - have I overtightened them?

hello,

I recently finished a water cooling setup. However, at first I got a leak. I therefore had to drain the system to sort it out.

In doing so, I had to take the tubing off the fittings. I noticed at the time that there were indentations on the tubing from where the "screwy bit" makes contact. First time round, once I had tightened as much as possible, there was a small gap between the screw bit, and the base of the fitting. However, second time round, after fixing the leak problem (caused by Swiftech design, standard third party o-rings don't create a seal), the screw bit went much further. I had the fitting screwed into the block, put the tubing on, and screwed the "screwy bit" down. Without using pliers, the screw bit went almost all the way, leaving practically no gap at all. It was easier to tighten too. Could I have overtightened it?

And should I be worried it was a lot easier to tighten the second time round? I'm afraid the tubing could be cut into.

I'm using Tygon 7/16" ID 5/8" OD tubing and bitspower compression fittings (same size, 7/16, 5/8)

I've included some photo's, incase my barely understandable description doesn't make any sense :p:

http://i185.photobucket.com/albums/x...k/IMG_3563.jpg
http://i185.photobucket.com/albums/x...k/IMG_3564.jpg
http://i185.photobucket.com/albums/x...k/IMG_3565.jpg

EDIT: The extent to which I tightened the fittings on the blocks is pretty much the same as how much I've tightened the ones shown above, at the bottom. (reservoir).

Very difficult to say. I don't watercool (yet) but it looks as if these fittings are designed to be hand tightened - pliers or other tools shouldn't be used - either where the fitting screws into the waterblock (which I assume uses an O seal) or the comptression fitting itself.

It may be that by using a bit too much force initially you have deformed the tubing, so it will be easier to tighten on re-assembly. You have two options really:

1. Fill and test the sytem with the water block removed to see if it leaks (a good idea anyway.

2. Fill and test the system in situ, with a tissue ready if it does leak.

If it does leak, then you can cut the end off the tubing so that you are compressing a bit that hasn't been compressed before, or if you can't do that, replace the tubing.

Ah, sorry I wasn't clear dude. After sorting out the initial leak and draining the system, I removed all the hardware (had to do so anyway because I messed up a screw hole on the board). I then filled it up again (JUST had enough coolant left, very lucky), and it's been like that ever since last Thursday. I've had it on and off regularly just to check for leaks. I'm still waiting for a replacement board, so I've had plenty of time to leak test, bleed etc. I haven't had any leaks so far.

What I am worried about however, is the tube deforming and tearing over time. Right now I have no problems, I do have concerns about them developing though.

it wont tear and it will be easy the 2nd time, you need to check every week for a month and then every month or so as they can work loose.

as for the fitting on the left thats a time bomb if you can screw it up to the metal as it will no longer be tight enough.

compression fittings should never be able to make contact like that.

maybe remove it and put plenty of ptfe round it so it doesnt screw into the res as far.

hello Gonzo,

Do you mean the fitting is being blocked by the plastic on the reservoir, preventing it from being tightened enough?

I've leak tested it for a while, haven't had any problems. Do you mean it could start leaking, or are you saying the whole hose/fitting could come off?

Thanks!

it could leak if it is tight to the housing of the res, you need to check now and again and it will tighten a little.