Loose Catch Can Hose (Rubber)

Hello everybody,


I installed a Billet Catch Can in June 2020 after it was highly recommended by several folks on here. Everything has been working great with it and I was surprised how much oil the can was catching each month.





Unfortunately, starting in November 2020, when the weather started to cool down, I noticed that one of the rubber catch can hoses that went from the engine to the catch can started leaking. (see video below)





It seems to be leaking a mixture of water & oil, but mostly oil as the liquid is yellow/gold. Also smells like engine oil. It seems to be leaking enough to make it onto the outer hose. As I was trying to re-connect the hose to the engine, I noticed the hose was very slippery. I had to wipe it down several times before I could get a good enough grip on it. I also noticed that the hose will slip off very easily now. This is probably due to all the water/oil that has leaked inside the hose and where it connects to engine.


I'm not sure if the heat from the summer then the cold from the winter caused the diameter of the hose to widen. Either way, I want to replace the hose with a tighter fitting one, or clamp it down using one of these metal hose clamps. Which route do you guys think would be best? And have any of you with Billet Catch Cans experienced this problem?

 

Ive never had an issue with mine, did you use the supplied hose or did you use different hose? Looks like you mounted differently then mine.

 

The issue you're dealing with is thermal cycling. As the temperature of the hose and metal fitting increase and decrease, they both swell and contract. During this process the clamps can stretch. In the summer the temerature swing isn't too bad so the stretch of the clamps is generally not enough for the union to leak. In the winter, the temperature swing can be great enough to cause leaks. Many years ago OEM's started using "constant torque clamps". Also known as "constant tension clamps", these clamps basically deal with this phenomenon by providing a clamping force with additional spring action so it maintains proper clamping force while the union swells and shrinks during times of thermal cycling.
Unfortunately, most aftermarket components, like your catch can, generally utilize far cheaper hardware such as basic worm gear hose clamps which do not offer any protection against thermal cycling. Bottom line, either replace the cheap clamps with better quality constant torque clamps or plan on tightening your cheaper clamps every fall.

 

UPDATE:


1. I went to check on the hose this morning, before starting the engine. Noticed it was already wet with water/oil on the outside of hose. Found this to be strange as I thought the leakage occurred while the engine was running. May be condensation rather? Car is parked in a cold garage.


2. After starting up the engine, I went to back to the hose to see if I could seal the connection more. Noticed when I went to move the hose, I was able to seal the connection a lot better, without the hose moving back off. (see picture below). Could this be due to suction once when engine is running?





When the engine is off, the hose hangs off a bit more. (see video below)

 

I used the supplied rubber hose from Billet. Unfortunately I think it's a lower quality hose due to it being made for the 3.5L V6. Kind of sucks they cut a corner there.

 

This looks like the answer I was looking for! I am going to NAPA tomorrow to buy a couple constant torque clamps. Thank you so much for this tip!

 

Ive

 

I have not installed mine yet. I am installing a catch can, air/fuel gauge and supercharger all at the same time as soon as the supercharger gets here.

 

We can't wait to hear your report.