I was wondering if coolant hoses to the radiator have any thermal properties that degrade over time. In other words, would they allow coolant to become hotter over time? I have a 01 Jeep Cherokee with 200k. The hoses have never been replaced, but they're not leaking either. I didn't know if it would be worth it to just replace them. At the same time, is it actually worth it to wrap them with heat shield to help lower the temps maybe a few degrees? Any answers will be greatly appreciated.

 

Cheap insurance, they do break down over time.

 

Time to get new ones if you haven't yet. Thats cheap insurance, and smart preventative maintenance. Wrapping it in heat shield isn't gonna help. The sole purpose of coolant is to cool your vehicle down by transferring heat from your engine to your radiator then to the air running thru the rad. So if any, it would help to move the heat from the coolant to the hose to the air. There is not going to be a noticeable difference in temp change in this anywhere.

 

Thanks for the responses. I'll go ahead and buy some this weekend.

 

Take it from a plastics engineer. Those hoses are built for heat. Not knowing the specific compound I'd say you wont run into degredation due to high temps unless you hold a flame to them. Plastics and rubbers are some of the best thermal insulators ever. So heat grander from coolant to hose to a warm engine bay would be minimal at best. That's why your hoses take a really long time to cool down. Most of your degradation is going to come from the coolant itself and petroleum based products (engine oil and grease) on the exterior of the hoses. The reason why hoses don't last forever...high heat exposure over time equals an accelerated break down of natural decomposition. Which is minimal in comparison to most dry rot that is seen over time.

 

http://en.wikipedia.org/wiki/Heat_transfer

 

10 year old hoses owe you NOTHING. And you often can't tell that they are deteriorating from the inside out.

Replace them. There are only a few of them and any money spent on cooling system maintenance is money well spent.

While you are at it, review all other cooling system components. Thermostat, fan clutch, radiator, water pump.

You have an 01, which from the factory came with the "infamous" 0331 cylinder head, which has a casting defect between cylinders 3-4. An overheat virtually guarantees that this head will crack.

Don't let this happen to you.

 

Just a thought.. some models have a spring inside the lower hose to prevent it from collapsing. If yours has one you might save it and re-use it in the new one. They don't usually come with the new one. My '93 didn't have one, but the new hose seemed much thicker and was ribbed, i guess for extra strength.

 

Thanks TJ. Well, I just did a flush with Prestone and refilled tonight. My fluids still looked really good. I don't know if that means anything. The fluid was still a vibrant neon green. New hoses on.

The thermostat is the plug going directly in the front and near the valve cover, correct? I know that one still works because I forgot to plug it in the other day after I replaced my valve cover gasket. Oops. CEL gave me a code right after I started driving.

How exactly do I check my radiator, fan clutch, and water pump to ensure they're tip top? Any suggestions? I'm new to auto maintenance and repair, but I really do enjoy it and the peace of mind it brings.

I appreciate your response in advance.

Thanks SpacedOut. And everyone else too.

Sincerely,

Captain Cherokee

 

Captain Cherokee,

No, the thermostat does not connect to the valve cover. It is the round housing in front of the valve cover with a hose leading into it.

I highly recommend you get a maintenance manual. It is absolutely essential to the process and education.

Here is a link to a licensed, legal factory service manual for your 2001. $7.95. A deal. It is a digital copy. You can search ebay for a hardcopy as sometimes they pop up there.

http://www.pacificcoastmanuals.com/F..._cherokee.html

 

Thanks. I've been looking for one but everyone says Chilton's is horrible and that's all that's available around here. I've just been reading as much on forums as possible. I'll pick one up. Thank you again.

CC

 

Pop the hood, start the engine and kill it. If you can get to where you can see the fan after reaching in and turning the key off an the fan is still turning, replace the clutch. If the water pump isn't leaking it's probably good but with that high of mileage, I'd replace it $32 for lifetime warantee is worth it. I just did mine and I only have 140k. Radiators are all junk copper/brass but there are aftermarket ones available