Trouble completely bleeding system...

hey all... I seem to be unable to get rid of a bunch of 'micro-bubbles' in my system. This is what I'm running:

Danner Mag 3 Pump
White Water Aluminum-Topped CPU Block
Swiftech MCW50 GPU Block
'86 Chevette Heater Core
Criticool WaterPlant Reservoir (6 tall inch cylinder, from criticool.com)

There seems to be alot of turbulence in the system, alot of it inside the reservoir. When the system is not running, there is a slight foam that settles in various parts of the system... but as much as I keep bleeding out, it keeps coming back. I believe i've reached a plateau in this situation where i cant get any more out. Wondering if anyone has a similiar experience to give me advice on what to do...

you can try pinching the lines....but all i did was let it run and eventually all the bubbles ended up at the top of my reservoir....is the reservoir the highest point in your setup?

i shake/tap the rad to get the air trapped in there loose.

The reservoir is the highest point... there is one other high point that air likes to get stuck in, and was very difficult to get out it out, I eventually stuck a T fitting at the crest of it and capped it so I could let the air out from that point... works really well as the air is always under pressure there and comes right out.


I've been moving and rotating my HC very consistently... I thought I'd be able to get rid of these little microbubbles easily after I fixed my Danner Mag 3 (Had the reknown leaking around the impeller housing... some JB Weld fixed it up, very nicely, and easy too!) As that was leaking water and also letting some air into the system.

I think its just a poor design on the part of this reservoir...similiar reservoirs have a section of tubing that attaches inside the res... and I think that limits the turbulence... (its like a whirlpool/cyclone in there!) Pretty hard to modify, so I'll have to live with it for awhile. I'll continue to run / bleed and see what happens.

Well I get a majority if my air bubbles out by leaving the system off for a little while then just cycling the pump intermitently.

Check all of your hose connections. It sounds to me like you have a very small air leak somewhere that is continually letting air into your system.

Sniperboy said:

Check all of your hose connections. It sounds to me like you have a very small air leak somewhere that is continually letting air into your system.

Click to expand...

This is a common occurrence, especially with powerful pumps.

A small leak can exist that does NOT let any visible water out but will let air into the system.

Do you have clamps on every barb/fitting?
Are they tight enough...or too tight? (Clamps that are too big can actually create a leak.)

Yes, I use metal worm-drive hose clamps on all connections, ive been very careful about placing them, as I had one on wrong once and a new lake was formed on my video card...live and learn.

I'll double check those again though...

I talked to another guy who has the same reservoir, said he experienced the exact same problem... my situation nearly mirrored his, so I'm still sold on a design flaw for now. I'll keep tweaking.

My only other though is that I have seen some people saying that their reservoirs can actually make bubble problems worse...

I don't use reservoirs, other than a few experiments, so I don't really know what works best to fix this if it is the problem...
Two things I have heard of people doing:
Using a sponge in the reservoir to slow down the flow where it may be generating bubbles
Inducing a "swirl" effect to help keep the water in the reservoir long enough to get rid of the bubbles.

How effective those are, I have no clue.

Good luck, and keep at it!

That "swirl" effect can create bubbles though too.

Teha ir goes down the middle too far and gets sucked in.

i have the same resservoir, u just got to keep topping it off at the t-line on top of the res. as the air comes up the water level will drop and eventually all the air bubbles will be gone. I know cause i have hte same problem bleeding since i have 2*mcp600 in a series.

Top off the res as high as possible. Run it for up to 24 even 48 hours. Also try switching the direction, if you have to(in the top out the bottom or vise versa). maybe even find a way to slow flow until the "foam" gets worked out. As the foam forms bigger bubbles it will be harder to get sucked into the loop.

patience, patience.

Good luck.

I agree that the first thing to do is give it some time. Make sure you turn the pump off for a few seconds every once in a while to get any air that accumulates in the pump or blocks. You might also pick up some plumber's putty to temporarily lump around your connections so you can track down any leaks.