When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I just replaced the water pump on my 1986 F150, 300.
(Thanx to all the guys who gave me tips ).
When i refilled it with coolant it would only take about 2/3 of what I took out.
I assumed it was just an airlock so I let it idle awhile but all the pressure stayed up top.
Could this be aproblem with the thermostat?
When you fill it, the thermostat is closed, so it blocks some of the water from getting through. I usually squeeze the hose to "burp" it effectively drawing in some water while squeezing air out. Since you have run it some, you may be able to get some more in.
I don't know if it applies to you, but I like to drill a small hole in the thermostat to let the air come out. 1/16" is all you need, but I usually use an 1/8" bit. Some say it lets the motor run cooler, but I don't buy that... May make it take a little longer to heatup though.
Also I run the car / truck first with the cap off so you can add coolant as it drops off, and you'll know exactly when the t-stat opens up.