Heater hose replacement

[Wd71MC]

I’ve got a quick question when replacing the heater hoses do you have to drain the entire radiator. Thanks Wes 

[cny first gen 71]

I'd say probably or at least most of it. Your probably still going to loose some anyhow I would normally just drain it all down before changing any hoses. 

[jft69z]

Another question sort of related to Steve's answer, when was the last time you changed/flushed the coolant?

[420ponies]

I'm on my 3rd set of hoses since '08 . The coolant has been changed about 6 times since '08. I can't believe how much coolant this BBC takes after my swap.

[stangeba]

When I replaced the heater core in 2009 I replaced the heater hoses and coolant.

It has been 15 years and 18,000 Miles.

I just jinxed it..............................................

[Chevy Dave]

If you use Gates Green Stripe or Napa Fleet heater hose, you will probably never need to change them again. These hoses last a very long time and are worth the higher price.

[Scott S.]

Every spring.

But then again, I drain the entire system for the winter up here. 

[cny first gen 71]

20 hours ago, jft69z said:

Another question sort of related to Steve's answer, when was the last time you changed/flushed the coolant?

Oh that's a good thought,  I didn't think of that. I've changed mine a couple times and one time by accident when the alt belt broke and it overheated lol.

[Montemedic]

2 hours ago, 420ponies said:

I'm on my 3rd set of hoses since '08 . The coolant has been changed about 6 times since '08. I can't believe how much coolant this BBC takes after my swap.

Go big or go home !!!

[Wd71MC]

19 hours ago, jft69z said:

Another question sort of related to Steve's answer, when was the last time you changed/flushed the coolant?

Well I purchased the Monte Oct of 2023 and I’ve not changed or flushed the radiator. So that’s probably something I should consider doing since I’m draining the radiator anyways. Thanks Wes

[Scott S.]

Depending on the coolant one uses, it can also gum up the thermostat to.

[Wd71MC]

18 hours ago, Scott S. said:

Depending on the coolant one uses, it can also gum up the thermostat to.

Thanks Scott what coolant would you suggest. Thanks Wes

[Marks71]

There is a thread here that addresses that, along with the use of distilled water. I believe that it was Joe that posted  a real good technical bulletin on the subject. I’m sure someone here can post a link to it. But basically we should be staying with the green and distilled water. I just use a major brand such as Zerex, Peak or Prestone. 

[Scott S.]

Hi Wes,

I've been using Prestone "Aluminum compatible" since I got Montelishi.

As I said earlier, I drain her for the winter, and come spring. I hook up the hose to a "tee" in the heating line and run the engine with the fresh water for about 5 minutes. 

That way I can check to be sure the thermostat still operates. 

After shutting down and draining, I check the A/F from last year to be sure it's still good, then pour it back back in and top up with fresh A/F (unmixed) fire her up, and check it again.