leak from lower rad to t stat hose AND under water pump
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CF Junior Member
Joined: Aug 2025
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which water pump is better for the express, AC DELCO GOLD, GM, gates? I want the best. Which thermostat is better, the ACDELCO 131160 or MOTORAD 523190 or GM one(if there is one.) A reveiw was talking about how the aC Delco pumped snapped at the pulley on an express. is this common? Maybe GM is best for everything? GM often recommends AC delco though. Im looking at pulling the trigger on a $130 AC delco from rock auto. THE GM pump is $75 more!
No All I find is strange that I don't RUn the vehicle for days and let it sit, and then all of a sudden is starts leaking around the water pump. THAT Is what is weird. And the fact I haven't seen any residue in that area for a while, but somehow fluid was coming out.
No All I find is strange that I don't RUn the vehicle for days and let it sit, and then all of a sudden is starts leaking around the water pump. THAT Is what is weird. And the fact I haven't seen any residue in that area for a while, but somehow fluid was coming out.
Last edited by neatchevy; Oct 5, 2025 at 3:07 AM.
CF Active Member
Joined: Jun 2022
Posts: 190
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From: Pensacola FL
Leaks like this can be funny sometimes. I've seen them leak a puddle one day then sit idling for an hour with just one drop of coolant hanging from a low point.
I have that going on with an older Nissan Maxima right now. The car has been sitting unused for a while needing some repairs I haven't gotten too. I would fire it up and move it once in a while. Maybe drive it up to the store and back. One day I fire it up to let the battery charge and it starts leaking from the pump enough to leave a puddle and a trail when I move it around the driveway. I park it again, come back a month or so later, top the coolant off and fire it up again. No leak!?!? I let it run for about 1/2 hour to charge up while checking on it and monitoring it with the Torque app while I'm working in the garage. Temp is perfect and just one drop of coolant hanging there. Nothing on the ground.
Don't know exactly what's going on but I'm adding a pump to the list of work the Maxima needs.
I have that going on with an older Nissan Maxima right now. The car has been sitting unused for a while needing some repairs I haven't gotten too. I would fire it up and move it once in a while. Maybe drive it up to the store and back. One day I fire it up to let the battery charge and it starts leaking from the pump enough to leave a puddle and a trail when I move it around the driveway. I park it again, come back a month or so later, top the coolant off and fire it up again. No leak!?!? I let it run for about 1/2 hour to charge up while checking on it and monitoring it with the Torque app while I'm working in the garage. Temp is perfect and just one drop of coolant hanging there. Nothing on the ground.
Don't know exactly what's going on but I'm adding a pump to the list of work the Maxima needs.
Thread Starter
CF Junior Member
Joined: Aug 2025
Posts: 81
Likes: 11
Leaks like this can be funny sometimes. I've seen them leak a puddle one day then sit idling for an hour with just one drop of coolant hanging from a low point.
I have that going on with an older Nissan Maxima right now. The car has been sitting unused for a while needing some repairs I haven't gotten too. I would fire it up and move it once in a while. Maybe drive it up to the store and back. One day I fire it up to let the battery charge and it starts leaking from the pump enough to leave a puddle and a trail when I move it around the driveway. I park it again, come back a month or so later, top the coolant off and fire it up again. No leak!?!? I let it run for about 1/2 hour to charge up while checking on it and monitoring it with the Torque app while I'm working in the garage. Temp is perfect and just one drop of coolant hanging there. Nothing on the ground.
Don't know exactly what's going on but I'm adding a pump to the list of work the Maxima needs.
I have that going on with an older Nissan Maxima right now. The car has been sitting unused for a while needing some repairs I haven't gotten too. I would fire it up and move it once in a while. Maybe drive it up to the store and back. One day I fire it up to let the battery charge and it starts leaking from the pump enough to leave a puddle and a trail when I move it around the driveway. I park it again, come back a month or so later, top the coolant off and fire it up again. No leak!?!? I let it run for about 1/2 hour to charge up while checking on it and monitoring it with the Torque app while I'm working in the garage. Temp is perfect and just one drop of coolant hanging there. Nothing on the ground.
Don't know exactly what's going on but I'm adding a pump to the list of work the Maxima needs.
Right, these are my thoughts exactly. time to change the pump. I can add a couple other things to the list of repairs on this van I need to make while I am changing the pump, I may as well change the idler and tension er pulley. the idler is discolored. The tensioner has play, I really think I should've talked the PO down some for this. AT least $500 off the price even though he was firm. I really hope my tranny makes it to at least 220k miles. I paid 10k for a van (not including CA sales tax.) with 158k miles, even though it's a 2015 I guess it doesn't matter, I probably paid too much. PO insisted the van was tip top shape. Apparently not. I do often see very beat off vans like this going for 10k though, and the sprinters I have seen go for a fortune.
also it is possible I suppose from what I've read that the leak can get flung out by the belt and fan, and not really leave any residue while driving. gravity can push it at high speeds and do strange things
ALso I wanted to know if an AFter market radiator like the one PO installed can cause problems in the system. From what I've read that these vans don't like aftermarket parts. Usually AC delco is all that is recommended.
Last edited by neatchevy; Oct 6, 2025 at 3:00 AM.
Thread Starter
CF Junior Member
Joined: Aug 2025
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Right, these are my thoughts exactly. time to change the pump. I can add a couple other things to the list of repairs on this van I need to make while I am changing the pump, I may as well change the idler and tension er pulley. the idler is discolored. The tensioner has play, I really think I should've talked the PO down some for this. AT least $500 off the price even though he was firm. I really hope my tranny makes it to at least 220k miles. I paid 10k for a van (not including CA sales tax.) with 158k miles, even though it's a 2015 I guess it doesn't matter, I probably paid too much. PO insisted the van was tip top shape. Apparently not. I do often see very beat off vans like this going for 10k though, and the sprinters I have seen go for a fortune.
also it is possible I suppose from what I've read that the leak can get flung out by the belt and fan, and not really leave any residue while driving. gravity can push it at high speeds and do strange things
ALso I wanted to know if an AFter market radiator like the one PO installed can cause problems in the system. From what I've read that these vans don't like aftermarket parts. Usually AC delco is all that is recommended.so AC delco professional unit is what it looks like a lot use for replacements. not the GM OEM one.
also it is possible I suppose from what I've read that the leak can get flung out by the belt and fan, and not really leave any residue while driving. gravity can push it at high speeds and do strange things
ALso I wanted to know if an AFter market radiator like the one PO installed can cause problems in the system. From what I've read that these vans don't like aftermarket parts. Usually AC delco is all that is recommended.so AC delco professional unit is what it looks like a lot use for replacements. not the GM OEM one.
Thread Starter
CF Junior Member
Joined: Aug 2025
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right, I just checked and it has slight drag when you try and turn it by hand COLD. It also has no play. IT also doesn't make any weird noises when driving as far as I can tell. i guess I can watch it for a sec tommorow. OEM fan clutches ARE NOT CHEAP AT ALL. already looking down the barrel of $375 to swap water pump, idler, tensioner, serp belt, thermostat. That's pretty good for that HONESTLY, it's the AC DELCO Professional water pump unit. All the youtube videos I've seen show the mechanics installing the aC delco PRO pump and not the GM genuine parts one.
guys, anything else I should get before beginning the job? I guess an 36 mm wrench (1 1/4) should be enough to get that fun clutch loosened up with a tap of a hammer?
guys, anything else I should get before beginning the job? I guess an 36 mm wrench (1 1/4) should be enough to get that fun clutch loosened up with a tap of a hammer?
Last edited by neatchevy; Oct 7, 2025 at 5:39 AM.
CF Active Member
Joined: Nov 2013
Posts: 167
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From: New Lenox ,IL. Eagle River, AK
leaks
Spring clamps are used for a reason. They expand and contract with the heat as worm clamps don't. Some newer radiators have plastic inlets and outlets. By tightening the worm clamps when leaking can make matters worse. If it was me I would take hoses off radiator and if the ports are plastic I would check for cracks. Just saying.
Thread Starter
CF Junior Member
Joined: Aug 2025
Posts: 81
Likes: 11
Spring clamps are used for a reason. They expand and contract with the heat as worm clamps don't. Some newer radiators have plastic inlets and outlets. By tightening the worm clamps when leaking can make matters worse. If it was me I would take hoses off radiator and if the ports are plastic I would check for cracks. Just saying.
CF Active Member
Joined: Jun 2022
Posts: 190
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From: Pensacola FL
I love worm clamps. They're fine as long as you understand how much tension to put on them.
I usually swap the spring clamps out with worm clamps when I take something apart. I keep cars for a long time and I know that I'll be the next one working on it. Maybe in my garage with all my tools handy or maybe on the road with the limited tool kit I carry. I know I can deal with a worm clamp no matter what. I can also force/hack things to work with a worm clamp if it comes down to working with the parts available to get home.
I usually swap the spring clamps out with worm clamps when I take something apart. I keep cars for a long time and I know that I'll be the next one working on it. Maybe in my garage with all my tools handy or maybe on the road with the limited tool kit I carry. I know I can deal with a worm clamp no matter what. I can also force/hack things to work with a worm clamp if it comes down to working with the parts available to get home.