Coolant Leak
03-30-2015, 08:52 PM
#1
Senior Member
Thread Starter
Coolant Leak
Truck is a 1989 F150 with 300 6. Got home and shut the truck off and it started to pour out coolant. So I opened the hood to see it pouring from the water pump. Took the belt off and the fan had about 3/4 in play per side. Went ahead got a new water pump and thermometer. Installed the new pump and thermometer and scraped the area around to get rid of the gunk and even sanded it a little. sprayed it and wiped it clean. I applied a blue gunk that the guy gave me when i asked for gasket adhesive on both sides as well. After reassembling at a leisurely pace i got everything together and after 1 1/2 gallons of antifreeze it was leaking again at the thermometer and waterpump. Threw some stuff and tore off what I could before it was too dark. Any ideas as to why it leaked? Did i not wait long enough for the adhesive or watever he gave me? Unsure of the name ill get it if needed. Thanks in advance guys
03-30-2015, 09:53 PM
#2
Did they not have an actual gasket for the water pump? Also, IME you shouldn't use RTV on both mating surfaces just one. Let it suit for 8-10 minutes then assemble and hand tighten. Then torque after an hour (or less, read the label). On the thermostat I used blue RTV and it worked great. I couldn't get a gasket to seal even with a new outlet.
03-30-2015, 10:50 PM
#3
1994 F150 XLT 5.8L 2wd
Did you replace both WP gaskets? When I did mine I did it like VM said, RTV on gasket side facing mount, hand tightened, waited a while then torqued it down. That being said it also took me 3 tries at the thermostat housing to get it to seal correctly, gaskets are cheap so that helps, but I also let it set up over-night before I added coolant on the last try and that seemed to help.
One tip I can give you is to fill it with water first to check for leaks, it's a PITA to try to save the coolant and can get expensive really quick just letting it flow to the ground. Take this time to also backflush (from both hoses) the heater core as well as removing the lower rad hose and flush out the radiator.
One tip I can give you is to fill it with water first to check for leaks, it's a PITA to try to save the coolant and can get expensive really quick just letting it flow to the ground. Take this time to also backflush (from both hoses) the heater core as well as removing the lower rad hose and flush out the radiator.
03-30-2015, 10:50 PM
#4
By thermometer I assume you mean thermostat, and it could have slipped in between the outlet and intake which would cause a huge leak. I did this it is an easy mistake to make.
I used rtv on both surfaces of my water pump and thermostat outlet and it doesn't leak. Just let it cure before filling it back up, it should say how long on the tube.
I used rtv on both surfaces of my water pump and thermostat outlet and it doesn't leak. Just let it cure before filling it back up, it should say how long on the tube.
03-30-2015, 11:05 PM
#5
Senior Member
Thread Starter
Yes i meant to say thermostat, my bad. I did receive a gasket for both the water pump and the thermostat. After thinking about it I only know for certain that the thermostat leaks because thats where I first spotted it and I should have put a towel there and saw if it stopped but I was pissed. I applied the RTV(assuming) to both sides of the gasket. I did replace the lower and upper radiator hose.
I can see where the thermostat would have came unseated. Ill be checking that first thing tomorrow. And then draining whatever is left into my bucket and filling with water to check for leaks. Are the gaskets for surely ruined after sitting overnight with RTV(assuming)?
I can see where the thermostat would have came unseated. Ill be checking that first thing tomorrow. And then draining whatever is left into my bucket and filling with water to check for leaks. Are the gaskets for surely ruined after sitting overnight with RTV(assuming)?
03-30-2015, 11:07 PM
#6
1994 F150 XLT 5.8L 2wd
Best to use a new gasket, not sure if it's different on the earlier I6 but on my 5.8 the WP has 2 gaskets, one between the pump and a small housing plate, then one between that plate and the engine mounts. Did you replace both? Does yours have both (for my curiosity)?
Never mind, looked it up and it's totally different from mine so just disregard.
Never mind, looked it up and it's totally different from mine so just disregard.
03-31-2015, 09:29 AM
#7
I always just put a coat of grease on both sides of the gasket and put it together. I haven't had any problems with leaking.
If you do use gasket adhesive (I like the blue stuff in a spray can best) you usually put the adhesive on the side of the gasket that goes to the piece that will come off. grease on the other side before install.
That way next time you can take the small piece to your workbench to clean it - you don't end up standing on your head trying to scrape stuck on gasket material off the engine block.
If you do use gasket adhesive (I like the blue stuff in a spray can best) you usually put the adhesive on the side of the gasket that goes to the piece that will come off. grease on the other side before install.
That way next time you can take the small piece to your workbench to clean it - you don't end up standing on your head trying to scrape stuck on gasket material off the engine block.
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03-31-2015, 09:44 AM
#8
Senior Member
Thread Starter
Yea that makes sense. It just seemed right because I had to scrape both sides of the thermostat housing and the engine side of the water pump. This was my first time with this repair and if I don't get it done today I'll end up having to get some help.