jaki30

Just discovered all the hoses in my 04 are original GM from late 2003 and early 2004. While they look ok, I have a feeling I should be changing them since they are so old. I just hate the idea of getting rid of original dated hoses. Naturally, it would mean a new t stat as well as heater hoses and radiator fill tank hoses. Currently have no problem with cooling.
Anyone have any recommendations?

redzg

I'll be contrary and say if they look and feel good, leave them be. Even at 15 years old. Though my advice may be more than a touch self serving, as I don't want to have to change all of mine...

Ceedub53

I'd start replacing them, asap.

Here is the part numbers of every radiator/water hose for the C5. I can't claim credit for it as it was posted here a week or so ago by someone else. I saved it, here it is. Btw, much thanks to the guy who originally posted it:

Coolant hose part numbers

I just replaced all 8 coolant hoses and 2 serpentine belts. I found some part numbers were difficult to find so I thought I would share this information. I used 7 Gates hoses and 1 GM hose. Three of the Gates were not a perfect fit and I will describe what I had to do.

Gates 22405 lower radiator hose, perfect fit, I reused original spring clamps.

Gates 22404 upper radiator hose, perfect fit, I reused original spring clamps.

Gates 18125 90* elbow hose from throttle body to coolant pipe. This hose is shorter on both ends and has a smaller o.d. I replaced both spring clamps with with worm clamps. I also bought a 1/4” brass barb and did the throttle body bypass mod. The mod allowed me to push the short ended hose onto the coolant pipe far enough to get a good seal. The other end of the hose goes onto the barb. There’s a lot of debate whether this mod is worth the effort. Since I already had the shorter hose the mod was a good solution.

Gates 19816 surge tank outlet to water pump hose. The surge tank end had an extra bend about 2” long. I cut that off and it worked. I reused both original spring clamps.

Gates 18127 radiator to throttle body hose. The radiator end is no problem and I reused the original spring clamp. The throttle body end has a smaller o.d. than the original hose. I replaced that spring clamp with a worm clamp. In my case, this is the end that I connected to the 1/4” brass barb for the throttle body bypass mod.

Gates 18447 heater core pipe to water pump hose, perfect fit, I reused both original spring clamps.

Gates 28417 heater core pipe to surge tank hose. This is a 5/8” straight hose. It actually measured 9/16” I.D. There was a lot of discussions about the original hose being metric with an obsolete part number. This hose fit perfectly and I reused the original spring clamps. I bought the minimum 6’ from Rock Auto and the packing slip showed a different part number 28491. I assumed this was because there is 6’.

GM 10408463 superseded by 10229488 surge tank inlet to radiator hose. This hose makes a 180* turn. The only option from Gates was a straight hose #28409. I imagine that you could bend it enough to make it work but I did not like that option so I bought the OEM hose. This hose was by far the most expensive one. It alone cost almost as much as all the other Gates hoses.

I also bought a new Gates surge tank cap. The new ones are 18 p.s.i.
The part number is 31544.

Gates K060798 main serpentine belt.
Gates K040420 air conditioning belt.

jaki30

Many thanks. While I was concerned with keeping the originality, I was afraid the reliability wasn't there due to the age of the parts. Would just be my luck for a hose to fail while on a cruise somewhere.
Whomever made that list deserves a huge thank you!

rrwirsi

For most of my repairs on anything I use the the 'not broke, don't fix it' philosophy. I have a 04 with 45K and the hoses look/feel great and verified by my go to mechanic. But if you feel better replacing them and spending the $$, do it. It is all about what makes you feel good when you turn the key on.

jaki30

I was actually surprised to find the hoses as good as they are. Also, I dislike getting rid of oem original parts. Unfortunately, the cooling system is like the heart of the car. No cooling...no driving. A loss of any part would result in the requisite r&r of all the components anyway. Prefer to do it in preferred conditions.

BigGun

Everything on the car is 15 years old. What else are you going to replace?

jaki30

I had the dealer change the transmission and Diff fluids last month.
Most likely after the radiator hoses, I will look at changing the shocks (Z-51) and then any of the rubber suspension bushings.
The car only has 56k miles on it, but, there are things that you change either on mileage or age.

3sACROWD

The better question is how old is the coolant? If more than 5 years old, it is due for flushing. Your call on the hoses.

Me personally, I don't worry too much about the hoses if they feel and look good. On the other hand, if I'm pulling an old hose off to replace a radiator, I will also replace the hose. My thinking is you have to stretch the hose over the barbed connection and the twisting action on the rest of the hose ,which is not normal to the regular function of the hose, could cause weak points.

Robrote

I've been messing around cars for 40 years and I think I've replaced only one rad hose that a blow out.

I also worked at a dealership for 11 years and can't off the top of my head remember them replacing hoses because they failed. I know it happens, but the odds are in your favor.

Route99

Just to give the credit, this was posted in May 23 by forum member seattle. It is very useful, and good for Ceedub53 to repost it.

We actually took a different approach. When I had the car apart last year for many different things I also replaced the 19 year old water pump and all the coolant hoses. I realize they may have gone longer, however, unlike some others, I have replaced more than one water hose in my life. Since much of the driving my wife and I do is trips of several hundred miles, my luck would be for the water hose to go 50 miles from civilization.

In place of the regular hoses, we replaced everything with Mishimoto silicone hoses. Our son gave us the info on the Mishimotos. He uses them in his 1,000hp drag cars so we figured if they'll work there, they will work in our car. Very pleased with them so far.

bobs77vet

if nothing else buy them so you don't get stranded....any one can put them on....but only if you have them

Ceedub53

"In place of the regular hoses, we replaced everything with Mishimoto silicone hoses. Our son gave us the info on the Mishimotos. He uses them in his 1,000hp drag cars so we figured if they'll work there, they will work in our car. Very pleased with them so far."

Your son's advice was sound. Those are elite quality hoses, they should serve you well.

Route99

Thank you, Ceedub53!

STRMLNE

Are gates hoses far better than GM? Why not just get oem?

leadfoot4

I highly doubt that GM makes their own hoses. I'm pretty certain that they contract them out to some major rubber hose manufacturer such as Gates or GoodYear, who makes the hoses and prints GM nomenclature on them. So unless you absolutely have to have cooling hoses with GM lettering on them, I can't see a need to go that route. FWIW, I also replaced the hoses on my 18 year old C-5, 3-4 years ago, as I don't like to risk being stranded somewhere away from home. I, too, went with silicone hoses.

STRMLNE

Just thinking that oem wouldn’t have any fitment issues or concerns. I don’t think the gateslistrd above are silicone.

leadfoot4

No, they aren't. I got my hoses from CF vendor CCA (custom Corvette accessories)….

STRMLNE

thanks for the recommendation. How was the fitment? Direct replacement or did you have to modify some?

leadfoot4

They fit like a glove. I also used the Gates "powergrip" hose clamps. They're the ones that are like HD pieces of "shrink tubing".....