Ok had this problem for a while and its getting on my tits. I have a clear dd res, its nearly impossible to get the air out of my system. I think the main reason for this is because their is a slight design floor in the res. To explain, I fill system bleed of air everything is good, put cap on res and then I get really small air bubbles, I think this is because the cap is hollow and thus adds air (whilst displacing water). This is then sucked downwards through the inlet (which then recircuilates because the outlet is next to the inlet. My pump is very close to the res (could this be the problem). Also I was thinking of buying a tank o matic, will I have problems with flow as its only 1/4 bspt barbs?
1/4 bspt is the thread - you can still fit bigger barbs thoght it is restrictive, if no more so than their NB block with is 1/4 NPT. If you have room in the case, diy the res and you can deal with the restictions without hassle.
could be several reasons. the one that comes to mind is possibly a tiny leak near the pump intake so its sucking air in slightly. fill and blead your system for 24 hours outside of your case in multiple positions with the pump and rad at lowest points and res at highest point and shake em up a bit once you think you have all the air out and watch what happens.
If you think the air is coming from the cap, fill the cap with epoxy, and be careful not to get any on the threads.
This sounds like a problem I had a while ago. You dindt specify what kind of res you have from DD, sounds like one of the round ones. But, I have a bay res, and when I put a more powerful pump on I had a problem with the suction being so great that even when the res was full it sucked out more water than was being immediatly replaced with more water, so it would suck in a little bit of air as the liquid was moving around. if it is a round res you might have a very small air vortex forming in there. And if its not any of those, you must have a small leak somewhere. Brew
Well I came up with an idea, which if i dont say so myself aint bad. I have filled the cap with water and stuck it in the freezer, this will then freeze (hopefully not droping out) allowing me to put it on displacing water with ice instead of air. Will let you know how it goes, I will also check the connections near the pump for tiny air leak.
it will freeze, expand and probibly crack the cap, I'd take it out if i were you. what about blue tac??
It will freeze expand and flow over the top of the cap as. Ever put bluetac in water? It will drop out, thin and be sucked towards the pump intake. Nice as that sounds think I will stick with plan a
good plan danny. Did you consider the fact that when ice melts it creates about a 1/4 of the original volume in water. I.e your cap would be full of ice, leave it to melt and there would be less water than there was ice. Still a good idea though, better than 'nought.
What sort of pump are you using daniel_owen_uk?? The DD res is quite small in respect to the amount of liquid it holds and it sounds like your pump is trying to draw water from it faster than the res can be filled...............maybe due to a restrictive set-up (blocks) Also is it the older DD res without the partition in between the inlet and out let as i know the partition was put in to solve this type of thing happening. Anyway, a bit of a pointless exercise but good fun never the less and might actually work in getting rid of all the air in the res good use of the grey matter daniel_owen_uk The cap off a DD res filled to the top with water Froz solid........and you can see the frozen liquid has expanded over the brim and melted again.......back to where we started Definitely worth a go......
I have the same res works fine with my setup, no air at all. Im using an Eheim 1250 with 1/2" tubing so its by no means got bad flow rate, also I love your solution, my idea was to drill a 1mm cole in the cap then stop it up with a bit of rubber, also using a syringe to top it right to the top. 'doc
oh come on, use a bit of common sense. When you put that cap into the reservoir, your going to displace the water that is up to the top with the bit of ice that is sticking out. Hence spillage, when the ice melts your not going to have anything to replace where the ice was (the bit over the brim). Am I not making any sense at all? I feel like I'm talking martian (I do actually speak fluent martian, although it hasn't helped me get any jobs, which is unfortunate ). Ok, so the above method is going to mean no bubbles, but surely it's going to also create slight negative pressure in the system. Is that going to be a problem? [EDIT] Hmm, thinking about it, it's probably so negligable that it won't make any difference. [/EDIT]
Come on m8 just admit it was genius Water isn't nearly 4 x the volume of ice, ever filled an ice cube tray? The negative pressure will be very negligible. Just looked it up and ice is 0.1764 etc. x bigger than water (4/3.4), in a 3-4ml cap thats a full 0.5ml of negative pressure
bah, I was at work and came up with a figure off the top of my head. I knew it wasn't right, but i'm a bloke, I exaggerate!
