Preventative maintenance?

[Leal77]

I recently bought a 1997 c2500 with the 5.7 and automatic transmission. Its got a pretty impressive 306,000 miles and still runs and drives great, previous owner had it in his companies fleet since 2000 and kept up on all the maintenance. Anyways, I don't have a lot of experience with these vehicles and I was wondering what I should do to help it last as long as possible outside of the normal tune-up. I previously owned a volvo 240 and was told to always keep an extra fuel relay because failure was pretty common, I'm wondering if there's anything like that I should just keep on the truck at all times. Its got good oil pressure, stays pretty cool and all the fluids look good. It mainly sat the last three years so previous owner isn't sure what has been replaced and is trying to find the records he had.

 

[Trio]

I recently bought a 1997 c2500 with the 5.7 and automatic transmission. Its got a pretty impressive 306,000 miles and still runs and drives great, previous owner had it in his companies fleet since 2000 and kept up on all the maintenance. Anyways, I don't have a lot of experience with these vehicles and I was wondering what I should do to help it last as long as possible outside of the normal tune-up. I previously owned a volvo 240 and was told to always keep an extra fuel relay because failure was pretty common, I'm wondering if there's anything like that I should just keep on the truck at all times. Its got good oil pressure, stays pretty cool and all the fluids look good. It mainly sat the last three years so previous owner isn't sure what has been replaced and is trying to find the records he had.

If you don't know all the history and it's been sitting for 3 years, then change ALL the fluids. All of them. Don't go by looks. Change the fuel filter. Do the thermostat while you have the coolant drained. Spark plugs and wires are a good choice. Check brake pads and shoes. Get the truck to a good baseline.

Then drive it and fix things that come up as you go along.

There is nothing unusual (like a relay) that you need to keep with you. I have had cars (usually european) where carrying a spare relay was an important as the spare tire.

And welcome!

 

[Leal77]

If you don't know all the history and it's been sitting for 3 years, then change ALL the fluids. All of them. Don't go by looks. Change the fuel filter. Do the thermostat while you have the coolant drained. Spark plugs and wires are a good choice. Check brake pads and shoes. Get the truck to a good baseline.

Then drive it and fix things that come up as you go along.

There is nothing unusual (like a relay) that you need to keep with you. I have had cars (usually european) where carrying a spare relay was an important as the spare tire.

And welcome!

Thankyou. It wasn't just sitting for three years, it was still driven occasionally from my understanding, it just kind of got phased out as they got newer vehicles. They did an oil change a few weeks before I bought it. Previous owner didn't know when the transmission fluid was last changed but it doesn't look burnt at all, I know you said not to go by looks but would you recommend changing it? I've read that the fuel pumps aren't the best, would it be dumb to replace it if its working?

 

[Komet]

Yes it's dumb to replace working parts because new parts are always a risk. You probably don't need to flush the trans fluid but a drain and fill with filter change would be good. Doing all the fluids and greasing all the zerks is a good idea.

 

[454cid]

Thankyou. It wasn't just sitting for three years, it was still driven occasionally from my understanding, it just kind of got phased out as they got newer vehicles. They did an oil change a few weeks before I bought it. Previous owner didn't know when the transmission fluid was last changed but it doesn't look burnt at all, I know you said not to go by looks but would you recommend changing it? I've read that the fuel pumps aren't the best, would it be dumb to replace it if its working?

I'd do a drain and fill on the transmission. You're not supposed to run ATF until it's burned.

Don't change the fuel pump. It's not a timing belt.

You might look at the brakes, and if you replace front pads, grease the pins. Also take a look at the rear brakes, and keep them adjusted.

Grease anyplace you find a zerk fitting unless it obviously has been done recently.

 

[Leal77]

I'd do a drain and fill on the transmission. You're not supposed to run ATF until it's burned.

Don't change the fuel pump. It's not a timing belt.

You might look at the brakes, and if you replace front pads, grease the pins. Also take a look at the rear brakes, and keep them adjusted.

Grease anyplace you find a zerk fitting unless it obviously has been done recently.

Yeah I'm aware you don't run it until it's burnt, but I'm honestly just not used to having clean trans fluid as the last two vehicles I've owned (91 240 & 84 D150) both had burnt fluid when I bought them so It was kind of a no brainer to change it out. I've heard some pretty conflicting info on how often/if at all you need to change your trans fluid. Fittings were greased before I bought it and I still need to inspect the brakes but they worked good on the drive home. I appreciate the info

 

[movietvet]

Welcome to the forum from Oregon.

Grease it wherever you can. Now, about the fluids. All fluids have a life/mileage expectancy. Except for the recent oil change you talk about, the rest you are unsure about. If you have no proof of the oil and filter change, then do it. All fluids are the "blood" of the component they are in. Oil for engine, ATF for transmission, diff fluids for differentials, transfer case fluid for the transfer case, coolant for the cooling system, brake fluid for the brake system and power steering fluid for the power steering system. Except for washer fluid, name just one of these that is inexpensive to repair. You can't. If you do not know 1000% for sure about the age/mileage on these fluids, change them and then you have a baseline on a 300k+ miles truck you just laid out money for. If you want to cross your fingers and take a chance, be my guest. I agree with what has been said by @Komet and @454cid about the fuel pump but also agree with @Trio about the fuel filter and the tune parts and I would also do the cap and rotor and for criminy sake, use good quality components when you do any work. I se no problem with this truck going 500k miles if it is not in a salt on the roads state. Take care of it and it will take care of you.

 

[Leal77]

What about the timing chain? I'm reading that gm doesn't provide a maintenance cycle for timing chains, they are supposed to last the life of the truck but I'm pretty sure that 300,000 miles is more than they expected these trucks to last. Are these interference engines?

 

[454cid]

What about the timing chain? I'm reading that gm doesn't provide a maintenance cycle for timing chains, they are supposed to last the life of the truck but I'm pretty sure that 300,000 miles is more than they expected these trucks to last. Are these interference engines?

It's not likely to break. If this were an earlier engine, it might have gotten a cam gear with nylon teeth that could strip, but that's not relevant on your engine. It could wear, and many guys do change them, but this shouldn't be a priority.

I have my original timing set at over 300K miles and have no plans to change it. I did have to do it on my Buick, as it had the nylon teeth that strip. It simply stopped running while going down the highway.

I've heard conflicting info on whether a SBC is interference or not. They're certainly not interference like a newer design import engine, but I don't think the chances of piston and valve contact is exactly zero, either. Again, this isn't something you need to be worrying about. It's not a timing belt that has a mileage and time replacement recommendation, and there are no guides, pulleys, or tensioner to fail that would throw the chain.

Assuming this is a daily driver, and not a hot-rod/race-truck, and you have reason to do the water pump, then maybe think about the timing set, since you'll be there already. I only say that since you do have over 300K miles, and it was a work truck.

However, you might consider looking at the cooling system. The small block Vortec engines are known for leaking intake manifold gaskets. A pressure test is simple to do, and bad intake gaskets can let coolant into the oil or hydraulically lock the engine, or keep it from starting. Given the truck has over 300K miles, it's probably happened already and been fixed, but could happen again depending on the gaskets used. Checking this would be much higher on my list than a timing chain.

 

[movietvet]

You will hear the chain or experience running problems long before a timing chain would break and cause valve to piston impact.