Collapsed upper radiator hose???
4th Gear Member
Joined: Mar 2009
Posts: 1,110
From: NJ
I got a 16 pound cap that came with the radiator. I have had nothing but trouble trying to find a replacment cap. That radiator is a sob and only take its own cap!!! I should have stuck with a standard waterpump. That where i shot myself in the foot. I went with the high flow version. I am trying to make this all work but am having a hell of a time .Also the uncertainty of the temp gauge adds to the frustration. With the extra piece of rubber the gauge sits in the middle. without it and 10 min drive its almost passed the P. I know it runs a bit hotter but the way the temp gauge works each ohm on the top end really gets the gauge moving.
I thought a 13 pound cap came with a cooling system that ran 165 degree tstat.
I thought a 13 pound cap came with a cooling system that ran 165 degree tstat.
My manuals have the t-stat opening at 188-195 and fully open at 212-215.
I think you have something else going on to build excessive pressure and a hot running engine. In theory, at least in my little world, the coolant level in the system is what it is. Sure it will expand a bit when hot, but unless it's drawing in air from someplace it shouldn't build an incredible amount of pressure even with a high flow pump. The pump would just flow faster with the t-stat open and build pressure "behind" the t-stat when closed.
I don't want to say head gasket, but a bad head gasket would force combustion gases into the cooling system resulting in increased pressure and a hotter runing engine.
How old it the radiator? It could be plugged up and that would cause a pressure buildup. With the engine running and the cap off (cold start) you should see coolant flow acrros the top of the core when the engine warms and the t-stat opens.
You should also make sure the lower hose doesn't collapse, especially when the rpms increase. If you see the hose collapse then chances are the hose doesn't have a spring and/or the radiator is clogged up. Kinda like sucking on a straw with your finger on the end.
Thread Starter
2nd Gear Member
Joined: Sep 2009
Posts: 183
From: florida
As far as I know a 13lb cap is pretty much the standard. I have never heard of a t-stat spec at 165 degrees.
My manuals have the t-stat opening at 188-195 and fully open at 212-215.
I think you have something else going on to build excessive pressure and a hot running engine. In theory, at least in my little world, the coolant level in the system is what it is. Sure it will expand a bit when hot, but unless it's drawing in air from someplace it shouldn't build an incredible amount of pressure even with a high flow pump. The pump would just flow faster with the t-stat open and build pressure "behind" the t-stat when closed.
I don't want to say head gasket, but a bad head gasket would force combustion gases into the cooling system resulting in increased pressure and a hotter runing engine.
How old it the radiator? It could be plugged up and that would cause a pressure buildup. With the engine running and the cap off (cold start) you should see coolant flow acrros the top of the core when the engine warms and the t-stat opens.
You should also make sure the lower hose doesn't collapse, especially when the rpms increase. If you see the hose collapse then chances are the hose doesn't have a spring and/or the radiator is clogged up. Kinda like sucking on a straw with your finger on the end.
My manuals have the t-stat opening at 188-195 and fully open at 212-215.
I think you have something else going on to build excessive pressure and a hot running engine. In theory, at least in my little world, the coolant level in the system is what it is. Sure it will expand a bit when hot, but unless it's drawing in air from someplace it shouldn't build an incredible amount of pressure even with a high flow pump. The pump would just flow faster with the t-stat open and build pressure "behind" the t-stat when closed.
I don't want to say head gasket, but a bad head gasket would force combustion gases into the cooling system resulting in increased pressure and a hotter runing engine.
How old it the radiator? It could be plugged up and that would cause a pressure buildup. With the engine running and the cap off (cold start) you should see coolant flow acrros the top of the core when the engine warms and the t-stat opens.
You should also make sure the lower hose doesn't collapse, especially when the rpms increase. If you see the hose collapse then chances are the hose doesn't have a spring and/or the radiator is clogged up. Kinda like sucking on a straw with your finger on the end.
The radiator is new(3 row). the heater core is new, the hoses are all hi miller hoses, the waterpump is new, timing cover is new. The engine is a reman.
I thought it was a head gasket at fist too. But what I did was place a radiator pressure tester. But instead if pumping the radiator I ran the motor. I monitored the pressure visually as the engine got to temp. I cant remember what the numbers where but I know the pressure was low @ 185 degrees. I can try it again tommorow. But when the engine is revving the pressure drops to almost nothing. No matter how long I rev it. The pressure rises in an instant when I let off the throttle. I dont know what that means exactly but I was praying it the pump. I also so started to think about the collapsed hose. If the head gasket was gone would it hold vacuum that well over night? I am no engine speacialist so if I am out of line please let me know.
Thanks Ivan
Last edited by ic237; Apr 18, 2010 at 09:05 PM.
4th Gear Member
Joined: Mar 2009
Posts: 1,110
From: NJ
When you stop revving the engine do you remember what the pressure was?
Maybe it is that water pump, but the collapsing hose is definitely because you have blocked the venting of the cap which would allow air or coolant back into the system. As 2+2GT pointed out, I'd worry about containing excessive pressure. Maybe someone with a high flow pump could jump in and attest to extra pressure.
Maybe it is that water pump, but the collapsing hose is definitely because you have blocked the venting of the cap which would allow air or coolant back into the system. As 2+2GT pointed out, I'd worry about containing excessive pressure. Maybe someone with a high flow pump could jump in and attest to extra pressure.
6th Gear Member
Joined: Oct 2006
Posts: 6,417
From: Cork, Ireland
well i'd try and get a 13-16 psi cap, so any extra pressure can go away. The extra pressure might even be from a blown headgasket etc. I don't recommend what I am about to say as you're playing with boiling water, but I'd just run the engine in idle til it warms up and when thermostat opens check if you get bubbles in the water. if yes you might put compression from the engine into the water through a cracked head or similar. then you will have massive pressure. it might be a blown headgasket or cracked head causing your problems, not the water pump
Thread Starter
2nd Gear Member
Joined: Sep 2009
Posts: 183
From: florida
well i'd try and get a 13-16 psi cap, so any extra pressure can go away. The extra pressure might even be from a blown headgasket etc. I don't recommend what I am about to say as you're playing with boiling water, but I'd just run the engine in idle til it warms up and when thermostat opens check if you get bubbles in the water. if yes you might put compression from the engine into the water through a cracked head or similar. then you will have massive pressure. it might be a blown headgasket or cracked head causing your problems, not the water pump
http://www.youtube.com/watch?v=sWBuMNpQVyc
Thread Starter
2nd Gear Member
Joined: Sep 2009
Posts: 183
From: florida
well i'd try and get a 13-16 psi cap, so any extra pressure can go away. The extra pressure might even be from a blown headgasket etc. I don't recommend what I am about to say as you're playing with boiling water, but I'd just run the engine in idle til it warms up and when thermostat opens check if you get bubbles in the water. if yes you might put compression from the engine into the water through a cracked head or similar. then you will have massive pressure. it might be a blown headgasket or cracked head causing your problems, not the water pump
http://www.youtube.com/watch?v=8NxA2wUPdrU
Thread Starter
2nd Gear Member
Joined: Sep 2009
Posts: 183
From: florida
1st Gear Member
Joined: May 2008
Posts: 102
From: Oklahoma
This may sound like a dumb question, but is your pump turning the correct way? What I mean by that is there is basically two differenet water pumps for the small block fords. On the later model small blocks they went to a reverse rotation due to the serpentine belt they were putting on ran on the back side of the belt. That or if you are running a serpintine belt the runs the water pump on the back side of the belt (on the smooth side) and trying to use an older standard rotation water pump - its the same difference.
just an idea i had while i was reading your posts.
just an idea i had while i was reading your posts.
Thread Starter
2nd Gear Member
Joined: Sep 2009
Posts: 183
From: florida
This may sound like a dumb question, but is your pump turning the correct way? What I mean by that is there is basically two differenet water pumps for the small block fords. On the later model small blocks they went to a reverse rotation due to the serpentine belt they were putting on ran on the back side of the belt. That or if you are running a serpintine belt the runs the water pump on the back side of the belt (on the smooth side) and trying to use an older standard rotation water pump - its the same difference.
just an idea i had while i was reading your posts.
just an idea i had while i was reading your posts.
This is what I bought with the help of summit racing staff.
Brand GMB North America
Manufacturer's Part Number 125-1420P
Part Type Water Pumps, Mechanical
Product Line GMB High Performance Water Pumps
Summit Racing Part Number GMB-125-1420P
Pump Flow High-volume
Pump Material Aluminum
Pump Finish Natural
Water Pump Rotation Clockwise
Quantity Sold individually.
GMB water pumps give you new OE quality in a high performance unit.
GMB high performance water pumps are designed and built to combat the engine overheating associated with higher performance and load applications. GMB high performance water pumps feature a precision-ground, heavy-duty steel bearing that's completely sealed and lubed for life. These GMB high performance water pumps have a specially modified, higher performance impeller that eliminates cavitation at all rpm and maintains maximum volumetric flow of coolant throughout the engine.
Additional features of GMB high performance water pumps are:
* Increase pump pressure up to 300 percent
* Eliminate steam pockets trapped inside the engine block
* Reduce engine temperature by 15-30 degrees
* Help increase horsepower
4th Gear Member
Joined: Mar 2009
Posts: 1,110
From: NJ
Wow, I don't know. I haven't looked at what my cooling system looked like when it was closed (clear tube), but that seems like a lot of air in there.
The engine sounds good otherwise. Did you ever burp the system and release all of the air?
The engine sounds good otherwise. Did you ever burp the system and release all of the air?