1995 Civic EX coupe w/B20B engine, M/T, 80k miles. Purchased two months ago.

Seller put this build together three years ago and used silicone radiator and heater hoses. I've never owned a car that had silicone hoses before this one. I've read and watched video that say silicone hose permeation rate is 15x greater than EDPM rubber and that water is lost permeated through but, glycol does not.

There is coolant loss in reservoir (aftermarket aluminum dual core radiator + slim can reservoir) and through testing: block test, leakdown, compression, no coolant in oil or oil in coolant, no excessive bubbles in radiator when revving engine, no white smoke from exhaust..the head gasket seems to be good (no breach). No loss of coolant in radiator. I cold pressure tested the coolant sytem a month ago (pressure wouldn't hold long due to tester fitment) and found a lose hose clamp leak where upper radiator hose connects to thermostat and another lose hose clamp leak on IACV. I tightened the clamps and check them once in a while and no new leaks to this point.

I plan to do another cold and operating temp pressure test soon but, I am wondering how much the silicone hoses permaeation rate factors into the coolant loss? It seems to be losing a cup of coolant every three weeks. Anyone using silicone hoses experiencing excessive coolant/water loss?

Permeation thread: Silicone Radiator Hoses: Not for the Street > MotoIQ - Automotive Tech, Project Cars, Performance & Motorsports

Video of permeation;

 

Does the level go back up in the reservoir when the car is hot? Because you just may.....juussst maaay, have a normal condition here. And hoses are cheap if it bothers you so much.

 

level does not go back up if your losing water

 

Scrap those pieces of junk and get OEM (if you can at this point) or good quality name brand hoses. Why even dick around?

 

Too bad MY statement said nothing about losing water. All though the main post did so I see where your brain might have crossed up. No biggie.

 

Go ahead and explain to me how the reservoir would raise back up to level if your losing water because of silicon hoses?

 

Thanks for all the replies.
Coolant rises in reservoir when hot as normal (pressure) but loss shows after cool down. I purchased this car a few months ago and it sucks to spend $100 to replace hoses that function but, facilitate water loss.
Engine bay smells like coolant constantly due to these **** hoses. Probably won't be long before I get sick of them and replace them all. Another problem with these hoses is they are a bit larger in daimeter than stock hoses so, they can't be used with the typical Honda spring clamps that are awesome. The worm screw clamps can cut into the silicone hoses and they tend to loosen over time and cause leaks.
But hey...they come in pretty colors..LOL