You would be surprised at some of the noises exhaust leaks can make.
More often than not, you won't hear them on a cold engine, then as the engine warms up, the leak will open up. Depending on where the leak is, I've heard them sound like birds chirping to firecrackers.
We had a bulldozer that had an exhaust leak that the operator swore there were birds in the exhaust stack. And since birds often would roost in the stacks, we tore it completely apart looking for the bird. It wasn't until we disassembled the exhaust manifold that I found one of the exhaust seal rings broken.
We put it all back together with new seals and his bird problem went away.
So, a couple of questions cropped up. Will this make things difficult for a future smog cert needed for DMV registration? The noise is coming from the engine area in front, is that normal? I realize the exhaust goes from the engine, all the way to the rear and out. Just making sure, thanks.
An exhaust leak can affect the emissions of your vehicle and depending on the EPA test facility, they can possibly fail you for the exhaust leak, at which time, you will need to have it repaired. Eventually, the leak will cause the oxygen sensor to read false information and make your engine run rich, because it "sees" more air in the system than the engine is actually putting out, then economy will suffer and it will trip the Check Engine Light.
I suspect the leak is minor right now or they would have suggested having it repaired. The fact that it sounds like they didn't try to sell you a bunch of work, is promising.
But eventually, you will need to have it repaired.
As for it coming from the front of the engine, the manifold may be leaking, in which case, could be leaking at the front of the engine, which would make a noise towards the front of the engine.
Did they say where the leak was? If we knew where the leak was, we may be able to help with that.
Well, my wife's Ford Exploder has been running fine but now my baby (truck) is having issues. Any help is appreciated.
2002 GMC Sierra 2500 HD 6.6L Diesel 4x4 Crew Cab, 110,000 miles. I notice a coolant leak on the right side, runs down the inside front fender to the ground. This is cold filling it, after I turn it off, etc. It's coming from the bottom area/under of the expansion tank.
From what I understand, the coolant in the radiator boils due to high temps, expands and then overflows to the expansion tank. Then when the coolant cools, it's fed back into the radiator. Does that sound right? Anyway, took it to the dealer, as the other place doesn't service diesels, and the prognosis is costly. They want to replace the water pump (where they say the leak is sourced) and suggest replacing the thermostat as well. My questions are the following:
What does the water pump have to do with coolant? Anyone know any good Diesel mechanics in San Diego? I see water pumps for under $100, is this something I should consider doing myself? - I don't need it within the next two weeks, so time is on my side. I could probably line up a friend who knows more than me about Diesels.
They want $2200 bucks...ugh, I just need to find a place for a second opinion (non dealer) but I also want to understand the technical info as well. Thanks again for any help.
Well, my wife's Ford Exploder has been running fine but now my baby (truck) is having issues. Any help is appreciated.
2002 GMC Sierra 2500 HD 6.6L Diesel 4x4 Crew Cab, 110,000 miles. I notice a coolant leak on the right side, runs down the inside front fender to the ground. This is cold filling it, after I turn it off, etc. It's coming from the bottom area/under of the expansion tank.
From what I understand, the coolant in the radiator boils due to high temps, expands and then overflows to the expansion tank. Then when the coolant cools, it's fed back into the radiator. Does that sound right? Anyway, took it to the dealer, as the other place doesn't service diesels, and the prognosis is costly. They want to replace the water pump (where they say the leak is sourced) and suggest replacing the thermostat as well. My questions are the following:
What does the water pump have to do with coolant? Anyone know any good Diesel mechanics in San Diego? I see water pumps for under $100, is this something I should consider doing myself? - I don't need it within the next two weeks, so time is on my side. I could probably line up a friend who knows more than me about Diesels.
They want $2200 bucks...ugh, I just need to find a place for a second opinion (non dealer) but I also want to understand the technical info as well. Thanks again for any help.
Diesels is what I do. I'm at work posting from my phone, so this will be short for now.
On the bottom side of the water pump, tucked up behind the pulley, is a weep hole. When the bearing wears enough to wear out the seal, coolant will come out the weep hole. So it is a possibility.
But.......you said it seems to be coming from around the recovery tank?
If so, then it is possible the radiator cap is failing and releasing. I'll explain more this afternoon when I get home and online.
Is it overheating or running warmer than normal?
Some parts stores will rent a cooling system pressure tester or may even test the system for you. Pressure test the cap and then the cooling system. Pressure testing those should give a good indication where the leak is coming from.
Well, my wife's Ford Exploder has been running fine but now my baby (truck) is having issues. Any help is appreciated.
2002 GMC Sierra 2500 HD 6.6L Diesel 4x4 Crew Cab, 110,000 miles. I notice a coolant leak on the right side, runs down the inside front fender to the ground. This is cold filling it, after I turn it off, etc. It's coming from the bottom area/under of the expansion tank.
From what I understand, the coolant in the radiator boils due to high temps, expands and then overflows to the expansion tank. Then when the coolant cools, it's fed back into the radiator. Does that sound right? Anyway, took it to the dealer, as the other place doesn't service diesels, and the prognosis is costly. They want to replace the water pump (where they say the leak is sourced) and suggest replacing the thermostat as well. My questions are the following:
What does the water pump have to do with coolant? Anyone know any good Diesel mechanics in San Diego? I see water pumps for under $100, is this something I should consider doing myself? - I don't need it within the next two weeks, so time is on my side. I could probably line up a friend who knows more than me about Diesels.
They want $2200 bucks...ugh, I just need to find a place for a second opinion (non dealer) but I also want to understand the technical info as well. Thanks again for any help.
Diesels is what I do. I'm at work posting from my phone, so this will be short for now.
On the bottom side of the water pump, tucked up behind the pulley, is a weep hole. When the bearing wears enough to wear out the seal, coolant will come out the weep hole. So it is a possibility.
But.......you said it seems to be coming from around the recovery tank?
If so, then it is possible the radiator cap is failing and releasing. I'll explain more this afternoon when I get home and online.
Is it overheating or running warmer than normal?
Some parts stores will rent a cooling system pressure tester or may even test the system for you. Pressure test the cap and then the cooling system. Pressure testing those should give a good indication where the leak is coming from.
Sounds like your talkin to the right guy,,The water pump itself aint too bad its just all the other stuff trying to get to it,,If you replace it yourself, dont skimp,,buy a good one!!!
Well, my wife's Ford Exploder has been running fine but now my baby (truck) is having issues. Any help is appreciated.
2002 GMC Sierra 2500 HD 6.6L Diesel 4x4 Crew Cab, 110,000 miles. I notice a coolant leak on the right side, runs down the inside front fender to the ground. This is cold filling it, after I turn it off, etc. It's coming from the bottom area/under of the expansion tank.
From what I understand, the coolant in the radiator boils due to high temps, expands and then overflows to the expansion tank. Then when the coolant cools, it's fed back into the radiator. Does that sound right? Anyway, took it to the dealer, as the other place doesn't service diesels, and the prognosis is costly. They want to replace the water pump (where they say the leak is sourced) and suggest replacing the thermostat as well. My questions are the following:
What does the water pump have to do with coolant? Anyone know any good Diesel mechanics in San Diego? I see water pumps for under $100, is this something I should consider doing myself? - I don't need it within the next two weeks, so time is on my side. I could probably line up a friend who knows more than me about Diesels.
They want $2200 bucks...ugh, I just need to find a place for a second opinion (non dealer) but I also want to understand the technical info as well. Thanks again for any help.
Diesels is what I do. I'm at work posting from my phone, so this will be short for now.
On the bottom side of the water pump, tucked up behind the pulley, is a weep hole. When the bearing wears enough to wear out the seal, coolant will come out the weep hole. So it is a possibility.
But.......you said it seems to be coming from around the recovery tank?
If so, then it is possible the radiator cap is failing and releasing. I'll explain more this afternoon when I get home and online.
Is it overheating or running warmer than normal?
Some parts stores will rent a cooling system pressure tester or may even test the system for you. Pressure test the cap and then the cooling system. Pressure testing those should give a good indication where the leak is coming from.
Well, it leaks with the cap off, so that's not the problem. I can fill it up about 2-3 oz. of Dex-cool, after not driving it for 2 days, not do anything, and it will leak within 2-3 minutes, if not sooner/immediately. I can see it pooling on the ground and dripping from the passenger side (under/near the expansion tank). The dealer pressure tested it and said the W.P. Most places I've been to won't touch my diesel. It's not overheating, although when I drive it, I drive slow and watch the temps...the temp looks normal. I haven't had to put the heat on full since it does not get over 210, ever.
I know I may not give you enough to help, but it's the best I got so far. Thanks.
Well, my wife's Ford Exploder has been running fine but now my baby (truck) is having issues. Any help is appreciated.
2002 GMC Sierra 2500 HD 6.6L Diesel 4x4 Crew Cab, 110,000 miles. I notice a coolant leak on the right side, runs down the inside front fender to the ground. This is cold filling it, after I turn it off, etc. It's coming from the bottom area/under of the expansion tank.
From what I understand, the coolant in the radiator boils due to high temps, expands and then overflows to the expansion tank. Then when the coolant cools, it's fed back into the radiator. Does that sound right? Anyway, took it to the dealer, as the other place doesn't service diesels, and the prognosis is costly. They want to replace the water pump (where they say the leak is sourced) and suggest replacing the thermostat as well. My questions are the following:
What does the water pump have to do with coolant? Anyone know any good Diesel mechanics in San Diego? I see water pumps for under $100, is this something I should consider doing myself? - I don't need it within the next two weeks, so time is on my side. I could probably line up a friend who knows more than me about Diesels.
They want $2200 bucks...ugh, I just need to find a place for a second opinion (non dealer) but I also want to understand the technical info as well. Thanks again for any help.
Diesels is what I do. I'm at work posting from my phone, so this will be short for now.
On the bottom side of the water pump, tucked up behind the pulley, is a weep hole. When the bearing wears enough to wear out the seal, coolant will come out the weep hole. So it is a possibility.
But.......you said it seems to be coming from around the recovery tank?
If so, then it is possible the radiator cap is failing and releasing. I'll explain more this afternoon when I get home and online.
Is it overheating or running warmer than normal?
Some parts stores will rent a cooling system pressure tester or may even test the system for you. Pressure test the cap and then the cooling system. Pressure testing those should give a good indication where the leak is coming from.
Well, it leaks with the cap off, so that's not the problem. I can fill it up about 2-3 oz. of Dex-cool, after not driving it for 2 days, not do anything, and it will leak within 2-3 minutes, if not sooner/immediately. I can see it pooling on the ground and dripping from the passenger side (under/near the expansion tank). The dealer pressure tested it and said the W.P. Most places I've been to won't touch my diesel. It's not overheating, although when I drive it, I drive slow and watch the temps...the temp looks normal. I haven't had to put the heat on full since it does not get over 210, ever.
I know I may not give you enough to help, but it's the best I got so far. Thanks.
Thanks Rudy!
I Think Tony is more familiar with this as I dont know this specific vehicle you guys are talkin bout,,But waterpumps are common fails..
It could also be a leaky overflow tank,, but doubtfull as I dont think it would drain your radiator dry with the vehicle just sitting.. It more than likely is the water pump ,, have you been able to climb under and look up at the WP using a flash light, looking for the leak,, As I said I'm not familiar with Diesels but could it maybe be that the leak is coming from the intake manifold gasket . or thermostat housing gasket???
Thanks man. I found a place to get a second opinion so I'm going to try that first but I'm getting nervous driving this thing around. I also lined up someone to help me do this ourselves if needed (water pump/thermostat).
ok good luck,, after thinkin bout it I would think that the therm or intake gaskets wouldnt leak while the vehicle not runnin and just sitting,, probably water pump!!! probably a good time to check/replace belts & hoses
Well, my wife's Ford Exploder has been running fine but now my baby (truck) is having issues. Any help is appreciated.
2002 GMC Sierra 2500 HD 6.6L Diesel 4x4 Crew Cab, 110,000 miles. I notice a coolant leak on the right side, runs down the inside front fender to the ground. This is cold filling it, after I turn it off, etc. It's coming from the bottom area/under of the expansion tank.
From what I understand, the coolant in the radiator boils due to high temps, expands and then overflows to the expansion tank. Then when the coolant cools, it's fed back into the radiator. Does that sound right? Anyway, took it to the dealer, as the other place doesn't service diesels, and the prognosis is costly. They want to replace the water pump (where they say the leak is sourced) and suggest replacing the thermostat as well. My questions are the following:
What does the water pump have to do with coolant? Anyone know any good Diesel mechanics in San Diego? I see water pumps for under $100, is this something I should consider doing myself? - I don't need it within the next two weeks, so time is on my side. I could probably line up a friend who knows more than me about Diesels.
They want $2200 bucks...ugh, I just need to find a place for a second opinion (non dealer) but I also want to understand the technical info as well. Thanks again for any help.
Diesels is what I do. I'm at work posting from my phone, so this will be short for now.
On the bottom side of the water pump, tucked up behind the pulley, is a weep hole. When the bearing wears enough to wear out the seal, coolant will come out the weep hole. So it is a possibility.
But.......you said it seems to be coming from around the recovery tank?
If so, then it is possible the radiator cap is failing and releasing. I'll explain more this afternoon when I get home and online.
Is it overheating or running warmer than normal?
Some parts stores will rent a cooling system pressure tester or may even test the system for you. Pressure test the cap and then the cooling system. Pressure testing those should give a good indication where the leak is coming from.
Well, it leaks with the cap off, so that's not the problem. I can fill it up about 2-3 oz. of Dex-cool, after not driving it for 2 days, not do anything, and it will leak within 2-3 minutes, if not sooner/immediately. I can see it pooling on the ground and dripping from the passenger side (under/near the expansion tank). The dealer pressure tested it and said the W.P. Most places I've been to won't touch my diesel. It's not overheating, although when I drive it, I drive slow and watch the temps...the temp looks normal. I haven't had to put the heat on full since it does not get over 210, ever.
I know I may not give you enough to help, but it's the best I got so far. Thanks.
Thanks Rudy!
I Think Tony is more familiar with this as I dont know this specific vehicle you guys are talkin bout,,But waterpumps are common fails..
It could also be a leaky overflow tank,, but doubtfull as I dont think it would drain your radiator dry with the vehicle just sitting.. It more than likely is the water pump ,, have you been able to climb under and look up at the WP using a flash light, looking for the leak,, As I said I'm not familiar with Diesels but could it maybe be that the leak is coming from the intake manifold gasket . or thermostat housing gasket???
Yup. ^^What he said.
Now, to answer your earlier questions to help you understand your cooling system a bit.
This may get a little long.
From what I understand, the coolant in the radiator boils due to high temps, expands and then overflows to the expansion tank. Then when the coolant cools, it's fed back into the radiator. Does that sound right? Anyway, took it to the dealer, as the other place doesn't service diesels, and the prognosis is costly. They want to replace the water pump (where they say the leak is sourced) and suggest replacing the thermostat as well.
Ok, the coolant can boil at high temps, but if the system is working properly, then it should never boil. Antifreeze/Coolant is the first defense to your cooling system boiling, it increases the temperature that your cooling system can boil and decreases the temps that it can freeze.
In addition to the antifreeze/coolant, the radiator pressure also increases the temps that it can boil. Which is why a large number of overheating problems can be directly related to a bad radiator cap. No pressure, lower boiling temps. A bad radiator cap can also cause leaks, higher running temps and allow contaminates into the cooling system.
The expansion tank is exactly what it says. It is for when the cooling system expands more than the system can handle. At that point, the cap valve opens and allows coolant to move into the expansion tank. When the system cools down, the cap allows the system to draw coolant back into the system. In a perfect system, there should never be any air in the system, if the cap, expansion tank and system are working properly.
Radiator caps should be checked at least every 3 years and I recommend that they be replaced just out of general practice any time the coolant is replaced. It's cheap insurance.
Ok, that out of the way, if it is leaking as fast as you say, it should be very evident where it is coming from, by looking from underneath.
The water pump on that engine is located off to the driver's side of the engine and at the lower portion of the engine. You should be able to see the hose connect to it from the bottom radiator hose. The weep hole on that one is probably on the side of the water pump.
If it is indeed the water pump, then the labor time is around 6 hours. Most shop rates range in between $85-$120/hour, it adds up.
A NAPA Tru-Flo water pump is about $140 and a Delphi OEM pump is about $350.
Add coolant ($28 -more than likely a shop will use premixed), thermostat ($26), radiator cap ($12) and incidentals about $120 (oil change, environmental fee, etc)
It's still far less than the $2200 you were quoted.
Call around to some independent shops and ask for a quote on a water pump replacement for your truck. If the quote is less than $1,000 ask them if they are using aftermarket or OEM parts and what warranty the parts carry. Ask them what brand they are using.
If they say "white box", then that is a generic brand and could be good, could be bad.
With the amount of miles on your rig, it is possible that it is indeed the water pump, but I would suggest seeing if you can get it pressure tested for a small fee from an independent shop and see what they say.
When you call for the quotes, ask them what they would charge to pressure test the cooling system to confirm your suspicions. You may find that they will do the pressure test for a reasonable fee.
But it could also be something as simple as a hose leaking at the connection to the overflow tank or the radiator.
Thanks. I will type up tomorrow on the puter. Too much to type up on iPhone. One question now though - it's leaking on the passenger side, so that should rule out the pump as you said it was on the driver side. And it leaks with the engine off, thus not using the pump. Is that correct logic? Does a pressure test "check" the flow to and from the expansion tank? Thanks so much for the help, I really appreciate it.
Water pumps usually leak the most when running, but can leak without the engine running. But since you said the leak is on the passenger side, I am suspecting either the resevoir/expansion tank or one of the hoses to it.
After looking at the cooling system for that truck, the resevoir is tied into the cooling system for that engine. So pressure testing it would pressurize the resevoir. Check the hose at the bottom of the resevoir. You may find it is leaking, cracked or worn thru.
Pressure testing the cooling system is really the way to determine for certain where the leak is. I have serious doubts it is the water pump, because of where you are saying the leak is.
When I get home, I can post a diagram of your cooling system to show you where to look.
Ok good, thanks. I'm on the right track then. I'm calling the shop I took the wife's truck (even though they don't do diesels) to see if they can at least pressure test it. Thanks again for the help.
Rats, I forgot the diagram on my desk.
But there are 2 hoses to the reservoir. One small one and one larger one. It wouldn't be uncommon for them to leak.
No worries man. Second opinion is the water pump. Could you help me figure out what brands I should be looking at? I don't mind spending more as I don't want to go cheap if that's not recommended. The dealer also recommended I replace the thermostat as well, do you recommend that? Thanks again for all the help, I really appreciate it.
No worries man. Second opinion is the water pump. Could you help me figure out what brands I should be looking at? I don't mind spending more as I don't want to go cheap if that's not recommended. The dealer also recommended I replace the thermostat as well, do you recommend that? Thanks again for all the help, I really appreciate it.
I'd go with OEM (Dealer) waterpump. Any independent shop can get the OEM pumps and install them. It doesn't have to be the dealer. I would replace the thermostat and radiator cap.
I'd have the hoses checked while they have it apart and if they seem like they may be a problem, now would be a good time.
Since you are opting on doing it yourself, have a manual handy. Or purchase AlldataDIY online for $26.95/year.
Alldata has all of the repair information for your vehicle.
Take a lot of pictures for reference when you go back together. Make sure all of the surfaces of the waterpump housing and thermostat housing are clean when you put it back together.
Any questions, give me a yell or hit up my website. There is a ton of diesel guys on my forums.
Well, I got the water pump replaced. It ended up being a lot of fun and having the right tools makes the job so much easier. It took about 5 hours but I walked out only spending about $300 on parts. The gasket on the bypass pipe (from the water pump housing to the thermostat housing) was bad so I had to change that out as well as the little 2 inch water line feed hose. We didn't replace the thermostats as those were still working fine. I found a great website called dieselplace.com (just GMC/Chevy) and they had a step by step walkthrough with pics. It sure came in handy. Thanks again for all the help.
Comments
More often than not, you won't hear them on a cold engine, then as the engine warms up, the leak will open up. Depending on where the leak is, I've heard them sound like birds chirping to firecrackers.
We had a bulldozer that had an exhaust leak that the operator swore there were birds in the exhaust stack. And since birds often would roost in the stacks, we tore it completely apart looking for the bird. It wasn't until we disassembled the exhaust manifold that I found one of the exhaust seal rings broken.
We put it all back together with new seals and his bird problem went away.
I suspect the leak is minor right now or they would have suggested having it repaired. The fact that it sounds like they didn't try to sell you a bunch of work, is promising.
But eventually, you will need to have it repaired.
As for it coming from the front of the engine, the manifold may be leaking, in which case, could be leaking at the front of the engine, which would make a noise towards the front of the engine.
Did they say where the leak was? If we knew where the leak was, we may be able to help with that.
2002 GMC Sierra 2500 HD 6.6L Diesel 4x4 Crew Cab, 110,000 miles. I notice a coolant leak on the right side, runs down the inside front fender to the ground. This is cold filling it, after I turn it off, etc. It's coming from the bottom area/under of the expansion tank.
From what I understand, the coolant in the radiator boils due to high temps, expands and then overflows to the expansion tank. Then when the coolant cools, it's fed back into the radiator. Does that sound right? Anyway, took it to the dealer, as the other place doesn't service diesels, and the prognosis is costly. They want to replace the water pump (where they say the leak is sourced) and suggest replacing the thermostat as well. My questions are the following:
What does the water pump have to do with coolant?
Anyone know any good Diesel mechanics in San Diego?
I see water pumps for under $100, is this something I should consider doing myself? - I don't need it within the next two weeks, so time is on my side. I could probably line up a friend who knows more than me about Diesels.
They want $2200 bucks...ugh, I just need to find a place for a second opinion (non dealer) but I also want to understand the technical info as well. Thanks again for any help.
On the bottom side of the water pump, tucked up behind the pulley, is a weep hole. When the bearing wears enough to wear out the seal, coolant will come out the weep hole. So it is a possibility.
But.......you said it seems to be coming from around the recovery tank?
If so, then it is possible the radiator cap is failing and releasing. I'll explain more this afternoon when I get home and online.
Is it overheating or running warmer than normal?
Some parts stores will rent a cooling system pressure tester or may even test the system for you. Pressure test the cap and then the cooling system. Pressure testing those should give a good indication where the leak is coming from.
I know I may not give you enough to help, but it's the best I got so far. Thanks.
Thanks Rudy!
Now, to answer your earlier questions to help you understand your cooling system a bit.
This may get a little long.
Ok, the coolant can boil at high temps, but if the system is working properly, then it should never boil.
Antifreeze/Coolant is the first defense to your cooling system boiling, it increases the temperature that your cooling system can boil and decreases the temps that it can freeze.
In addition to the antifreeze/coolant, the radiator pressure also increases the temps that it can boil. Which is why a large number of overheating problems can be directly related to a bad radiator cap. No pressure, lower boiling temps. A bad radiator cap can also cause leaks, higher running temps and allow contaminates into the cooling system.
The expansion tank is exactly what it says. It is for when the cooling system expands more than the system can handle. At that point, the cap valve opens and allows coolant to move into the expansion tank. When the system cools down, the cap allows the system to draw coolant back into the system.
In a perfect system, there should never be any air in the system, if the cap, expansion tank and system are working properly.
Radiator caps should be checked at least every 3 years and I recommend that they be replaced just out of general practice any time the coolant is replaced. It's cheap insurance.
Ok, that out of the way, if it is leaking as fast as you say, it should be very evident where it is coming from, by looking from underneath.
The water pump on that engine is located off to the driver's side of the engine and at the lower portion of the engine. You should be able to see the hose connect to it from the bottom radiator hose. The weep hole on that one is probably on the side of the water pump.
If it is indeed the water pump, then the labor time is around 6 hours. Most shop rates range in between $85-$120/hour, it adds up.
A NAPA Tru-Flo water pump is about $140 and a Delphi OEM pump is about $350.
Add coolant ($28 -more than likely a shop will use premixed), thermostat ($26), radiator cap ($12) and incidentals about $120 (oil change, environmental fee, etc)
It's still far less than the $2200 you were quoted.
Call around to some independent shops and ask for a quote on a water pump replacement for your truck. If the quote is less than $1,000 ask them if they are using aftermarket or OEM parts and what warranty the parts carry. Ask them what brand they are using.
If they say "white box", then that is a generic brand and could be good, could be bad.
With the amount of miles on your rig, it is possible that it is indeed the water pump, but I would suggest seeing if you can get it pressure tested for a small fee from an independent shop and see what they say.
When you call for the quotes, ask them what they would charge to pressure test the cooling system to confirm your suspicions. You may find that they will do the pressure test for a reasonable fee.
But it could also be something as simple as a hose leaking at the connection to the overflow tank or the radiator.
After looking at the cooling system for that truck, the resevoir is tied into the cooling system for that engine. So pressure testing it would pressurize the resevoir. Check the hose at the bottom of the resevoir. You may find it is leaking, cracked or worn thru.
Pressure testing the cooling system is really the way to determine for certain where the leak is. I have serious doubts it is the water pump, because of where you are saying the leak is.
When I get home, I can post a diagram of your cooling system to show you where to look.
But there are 2 hoses to the reservoir. One small one and one larger one. It wouldn't be uncommon for them to leak.
Let us know what you find.
I'd have the hoses checked while they have it apart and if they seem like they may be a problem, now would be a good time.
Alldata has all of the repair information for your vehicle.
Take a lot of pictures for reference when you go back together. Make sure all of the surfaces of the waterpump housing and thermostat housing are clean when you put it back together.
Any questions, give me a yell or hit up my website. There is a ton of diesel guys on my forums.