[KM Richards]

LS engines have this Coolant Crossover Hose that goes from one head to another... and I saw one recently that was a braided hose... anybody know where to find these for '09-'12 Colorado LS engines?

It can't be under too much pressure as the one that came on my truck from the factory doesn't even have hose clamps on it.

 

[cart7881]

I don't have an answer, but I looked at my engine (2011 LH) and it doesn't appear to have that configuration. The only coolant line on my engine, that crosses from one side to the other, is located below the throttle body and the Service Manual refers to it as a "coolant bleed pipe". On the passenge side it also connects to one of the smaller coolant hoses that come from the pump and go to the heater core. The ends of the tube are welded, much like a manifold, and it is retained to the head by bolts. Not much help there, sorry.

 

[KM Richards]

Here's a pic of the hose, I think they call it a vapor hose...

 

[cart7881]

Yeah, Looks like the one on my engine uses the same mount configuration as that. RockAuto has a picture of the OEM one, PN 12694768. Metal line with rubber hose for protection. RockAuto

 

[KM Richards]

Thanks! I looked on Rock Auto and did not see anything for my truck for this.

I was kinda hoping to do a braided hose kit... but, if it's just a vapor hose that is not under pressure like the rest of the cooling system, it's not likely to fail anytime soon.

 

[KM Richards]

I was just reading up and the Gates (GATES HHA147) part description says "Coolant Air Bleed Crossover Pipe w/ Protective Sleeve"

So, it sounds like the OE part is actually a metal pipe... so unless it's rotted and leaking, I wouldn't think this needs to be replaced due to age like I just did on my radiator hoses and heater hoses.

 

[20125.3BC]

European cars have long used cooling systems that required that all air be purged (also referred to as bled) for proper operation and often used a bleed hose to facilitate this. The hose was usually a short length of small diameter hose terminated with a bleed screw and was located such that it was the highest point in the cooling system. More recent models (the 2010s BMW M3 for example) have a bleed screw integrated into the cooling system, although they have often proven somewhat problematic.

I think it is pretty safe to say that the hose that is the topic of this thread has nothing to do with purging/bleeding the cooling system so it is curious that is referred to as a Coolant Air Bleed. The documentation for many of the LS engines (LS1, LS2 etc.) refer to it as a Coolant Crossover Host/Pipe/Tube (as does this thread's OP) and that seems to be a more accurate description of its function. I expect that the cooling system for the LH9 requires little beyond a funnel to refill the coolant system as the Radiator Cap is likely the highest point in the system. That said, the shop air powered coolant refill systems described in other threads on this site make the process so much simpler and cleaner that I would recommend using one if possible.

 

[cart7881]

Yeah, The 2011 GM Service Manual refers to it as 'Coolant Air Bleed Pipe'. On my 2011 5.3, there is a hose connected to a fiting on the right end of the tube. The other end of the hose is connected to the tube going to the heater core. Technically the hose could be disconnected to allow for air bleeding.

Not sure how accurate the 2009 GM Service Manual is, but it also shows a hose connected to that bleed pipe, but with the other end going to the radiator. The hose is called 'the radiator vent inlet hose'.

Whether or not it is needed is certainly a subject for discussion.