Is it normal for catch can's PCV hoses to collapse under vacuum pressure?

[green_henry]

I have a Radium catch can and have never bothered to look at it with the engine running until today (while bleeding the air from my new radiator). When the engine is off, everything seems hunky dory, but as soon as it starts, the PCV hoses to/from the catch can collapse because of the vacuum. I used the hose that shipped with the kit and it's only a few months old. Is this normal?

 

[ron@whoosh]

I have a Radium catch can and have never bothered to look at it with the engine running until today (while bleeding the air from my new radiator). When the engine is off, everything seems hunky dory, but as soon as it starts, the PCV hoses to/from the catch can collapse because of the vacuum. I used the hose that shipped with the kit and it's only a few months old. Is this normal?

no, that actually isn't

I've pinged my Radium contact - I'll report back

 

[felopr]

No they shouldn't collapse. My only way that would happened is if you install the in-hose checkvalve backwards but this kit doesn't have one.
I have a Damond Motorsports one and doesn't collapse. Those hoses are super strong, i think they are hydraulic rubber hoses

 

[green_henry]

No they shouldn't collapse. My only way that would happened is if you install the in-hose checkvalve backwards but this kit doesn't have one.
I have a Damond Motorsports one and doesn't collapse. Those hoses are super strong, i think they are hydraulic rubber hoses

Thanks for the feedback. Everything seems to run ok but it definitely doesn't look right.

For whatever it's worth, the kit shipped with Dayco 5/8" ID Fuel Line. I was surprised by how strong the vacuum is, so I can see why OEM is plastic instead of rubber.

 

[felopr]

vaccum is like 20 in/hg at idle , and like 25 in/hg while on decel engine braking
I think they use plastic because is cheaper for them to mold it those curves instead of using a good vacuum safe line
and cant really use a silicone hose for that since oil permeates the silicone hose

 

[Quisp]

vaccum is like 20 in/hg at idle , and like 25 in/hg while on decel engine braking
I think they use plastic because is cheaper for them to mold it those curves instead of using a good vacuum safe line
and cant really use a silicone hose for that since oil permeates the silicone hose

Tell Mishimoto that. Lol

 

[green_henry]

I contacted Radium via email today and they acknowledged that they have heard the same complaint. They are looking into alternative hose materials, and I hope to hear back from them soon.

If you have one, another thing to check is the dipstick. I noticed that the stick was loose and was starting to unthread from knob. That's probably the downside of it being attached to the motor mount -- the vibration almost certainly made it come loose. I'll be putting some loctite on that tomorrow; easy fix

 

[green_henry]

After surfing the web for a few hours, I'm thinking that the 5/8" hose is too big and needs to be dialed down to 1/2" (which will require new fittings). 5/8 vacuum ratings (where listed) are ~15 in. hg. whereas 1/2 jump to ~28 in. hg.

 

[felopr]

I contacted Radium via email today and they acknowledged that they have heard the same complaint. They are looking into alternative hose materials, and I hope to hear back from them soon.

If you have one, another thing to check is the dipstick. I noticed that the stick was loose and was starting to unthread from knob. That's probably the downside of it being attached to the motor mount -- the vibration almost certainly made it come loose. I'll be putting some loctite on that tomorrow; easy fix

Care to explain more? You saw the dipstick not flush all the way down?

 

[felopr]

After surfing the web for a few hours, I'm thinking that the 5/8" hose is too big and needs to be dialed down to 1/2" (which will require new fittings). 5/8 vacuum ratings (where listed) are ~15 in. hg. whereas 1/2 jump to ~28 in. hg.

My kit uses the factory fittings, is just plug and play imo. I think the error was to use fuel lines instead of harder ones like hydraulic lines

 

[green_henry]

Care to explain more? You saw the dipstick not flush all the way down?

As I was wiping off the dipstick, it felt a little loose and had clearly started unthreading itself. I tightened it back up and it was solid again, but I'm definitely going to put some loctite on it.

 

[a1b3d0]

Did you end up replacing the supplied hose from Radium? On the Mountune website someone mentioned they received a replacement.

 

[ron@whoosh]

Did you end up replacing the supplied hose from Radium? On the Mountune website someone mentioned they received a replacement.

if you have an older Radium kit and the hose has these issues, simply email Radium. They send out thicker replacement hose
[email protected]