What's causing my cooling problem?

[Methuselah]

While I was debugging the problems with the truck after the Nats I accidentally overheated. The temporary switches I used to turn on the electric radiator fans melted open.

Anyhow now I have a serious cooling issue. Even with the thermostat removed the truck just keeps getting hotter. The upper radiator hose is not overly pressurized. The radiator and fans are doing an excellent job of cooling, to the point that the radiator and return hose are cool to the touch.

So, what's an easy way to prove that the water pump is circulating?

Are there problems with the head gaskets/cylinder heads would cause this kind of cooling problem?

Thanks.

 

[93ty475]

Re: What's causing my cooling problem?

While I was debugging the problems with the truck after the Nats I accidentally overheated. The temporary switches I used to turn on the electric radiator fans melted open.

Anyhow now I have a serious cooling issue. Even with the thermostat removed the truck just keeps getting hotter. The upper radiator hose is not overly pressurized. The radiator and fans are doing an excellent job of cooling, to the point that the radiator and return hose are cool to the touch.

So, what's an easy way to prove that the water pump is circulating?

Are there problems with the head gaskets/cylinder heads would cause this kind of cooling problem?

Thanks.

i think your truck is in need of a stock fan and shroud...and the switch should go through a solenoid of some type when you wire it up...you shouldn't run such a big load through any 12 volt switch without a solenoid...at least one like the ones on your firewall for the fuel pump and such...i think you only really need a fan for under 25 mph, so maybe your electric fans aren't cut out for the job...you can't beat our stock shroud...also i would run a thermostat no matter what...a 160 or a 180...make sure you don't install it upside down if its possible...also make sure you have the correct waterpump that flows the correct direction...there are two types on the market...you need a reverseflow if im not mistaken, for these trucks...you should be able to see the water flowing if you remove the radiator cap, when the engine is somewhat cool...if you dont have a thermostat installed, the water should be flowing away, visibly...if not, you have to wait until the thermostat opens to see it flow...hth

 

[scotts4]

how was it running before you over heated ? Did it run cool or did it run hot ? Did you do any thing to the truck before the over heat ? need more info

 

[Methuselah]

Servando, you mean relay I think. Yeah I'll wire it up properly when I have time. Since the switches were clearly not rated for the current drawn by the fans (Ramchargers, which are shrouded by the way), Im just pluging the fans in directly after I crank the truck.

Of course I run with a thermostat, but I was hoping the thermostat was sticking and therefore removed it. It was my understanding that the truck would not heat up at all with the thermostat removed, but it is clearly doing that and then some.

It is that reason that has led me to believe the Edelbrock aluminum water pump has developed a problem. The water pump pulley was not properly secured which may have caused an eccentric rotation in the water pump vanes, contributing to its demise. I'll check it out tomorrow. I'd prefer to replace the water pump than replace a head gasket anyhow

I did lots of crap to the truck before it overheated. More than I care to list But it was running "fine" with respect to cooling before the switch melted open on the electric fans.

If no one can tell me an easy way to prove the water pump is properly circulating coolant, then I'll take it off tomorrow.

Thanks.

 

[Typhoon #1133]

no idea what your problem is. but when i took my thermostat out it took longer to heat up but when it got upto temp it went all the way up to about 200 deg. and would not go lower. i was told the coolant was going through the radiator to fast to cool it. good luck finding your problem.

 

[93ty475]

Servando, you mean relay I think.

yeah i think you're right :wink: i used one to fire up my new fuel pump and it worked great...if your problem just started, it should have something to do with the one of the last things you recently upgraded...thats a very pricey water pump from what i understand...no real way to check flow volume unless you disconnect a hose and fire it up...if your overheat probs are when parked, i'd look into a stock shroud and fan unless you have an a2a that doesn't lend itself to a stock fan setup...good luck

 

[Methuselah]

no idea what your problem is. but when i took my thermostat out it took longer to heat up but when it got upto temp it went all the way up to about 200 deg. and would not go lower. i was told the coolant was going through the radiator to fast to cool it. good luck finding your problem.

That's interesting. My radiator is cool to the touch, I can only assume this is not normal, as even the most efficient radiator would not cool 200*F+ coolant so well (my overheated temps of course). If coolant were flowing through the radiator too quickly to cool as you suggest, I would still expect the radiator to be warm to the touch.

I bought the pump used so Im not too upset at the moment. I would prefer that it is the pump rather than a head gasket or cracked head though, as I'd like to start driving the truck sometime soon

Yeah there's no turning back from the electric radiator fans now. Seems to me that they are working quite well despite the issues.

Thanks.

 

[Methuselah]

So I took the water pump out today. My guess was right, the water pump was not circulating coolant. The pump vane was completely separated from the shaft.

Not really sure how such a catastrophic failure could occur, even with it overheating. Would you guys trust a water pump that had the vanes welded onto the shaft? Think the balance might be an issue?

Anyone ever rebuilt an Edelbrock aluminum water pump?

Thanks.

 

[tytom]

My understanding is that You need specialised equipment to rebuild water pumps. The stock ones with the pressed on impellers can be rebuilt and most parts stores sell the rebuilt ones on an exchange basis. The Edelbrock, who knows? Probably Edelbrock can tell. I think if the blades came off then it was faulty and You should get a replacement . No way the blades can come off from overheating. If they do come off from overheating the that water pump is worthless,and cannot be trusted. A good thing to use would be a stock type
pump with a FlowCooler impeller disc. Cost like $ 10 from Summit and does help coolant flow. Rivets on the impeller. Even this does not throw off balancing ! Works great on my Trans Am which is one of the hardest cars to cool since there is no direct opening forward , the fans have to suck the air from under the car. When You put a thermostat in,always "cook" it in a pot of water to see if it opens fully at the right temperature. Even brand new ones should be cooked, I have seen faulty new ones! Good luck

 

[Methuselah]

Edelbrock tells me they'll rebuild the crapper for $65. Not unreasonable but not fantastic either, imo.

The replacement pump works great. In fact, even with the electric fans on low the truck isn't warming up quite as much as I would like!

Thanks for the help guys.

 

[93ty475]

So I took the water pump out today. My guess was right, the water pump was not circulating coolant. The pump vane was completely separated from the shaft.

Not really sure how such a catastrophic failure could occur, even with it overheating. Would you guys trust a water pump that had the vanes welded onto the shaft? Think the balance might be an issue?

Anyone ever rebuilt an Edelbrock aluminum water pump?

Thanks.

wow to think that one of the most favored waterpumps upgrades for us failed that way...i'm glad i didn't buy one now...it was a good think that you tore it down to get to the bottom of the problem...not the easiest task...did you have to remove both accessory brackets?

A good thing to use would be a stock type pump with a FlowCooler impeller disc. Cost like $ 10 from Summit and does help coolant flow. Rivets on the impeller.

that sounds interesting...do you just pull the stock pressed one and put this one on?

 

[Methuselah]

wow to think that one of the most favored waterpumps upgrades for us failed that way...i'm glad i didn't buy one now...it was a good think that you tore it down to get to the bottom of the problem...not the easiest task...did you have to remove both accessory brackets?

No you dont have to remove the accessory brackets to r&r the water pump. Not that it isnt annoying but it is easy by SyTy standards. It helps that I dont have a fan shroud or blades to remove before I start removing something useful.

Also, I replaced it with a new Edelbrock aluminum water pump... although my confidence is shaken somewhat in the brand it's still an aluminum pump and Im not about to trade that for a rusty stocker.

 

[tytom]

It has been a couple of years since I did mine but if I remember correctly You dont need to pull the impeller,just remove the back cover, drill into the impeller and rivet the disc to the impeller while still in place. Its a no brainer really, just make sure there are no shavings left in the housing after drilling.
All it is is a stainless dics with 3 predrilled holes and rivets in the kit. It is supposed to increase flow as well as decrease turbulence around the impeller . Helped my car. Low buck solution. If I was going to spend money on an aftermarket pump I would go electric that I can turn on and off , cooling engine after a run for example. They work great on streetcars too, just have to figure out how to use one with the serpentine belt, which is a pain.

 

[Methuselah]

A further bit of info for those interested.

Although it was pulling teeth to get this info out of the Edelbrock "customer service" it turns out that a 1 year warrenty comes with every pump you send to them for repair, even if it was not previously warrentied (such as buying a used pump as I did).

So, $65 + broken Edelbrock pump = like new warrentied Edelbrock pump.