Hello.
Just got a new thermostat, water pump, radiator and have air in the system.
Found this great instruction to burp https://reischeperformance.com/refill.html AND I cannot find the crossover plug to do it.
Already tried this https://www.f150online.com/forums/19...nt-system.html
It worked until I opened the radiator to make sure level was good and be done with it. Then gauge shot up again.
Have been looking all over for a picture of the crossover plug and finally just made account and asking.
PLEASE SOMEONE TELL ME WHERE IT IS.
Thanks.

 

Hello.
Just got a new thermostat, water pump, radiator and have air in the system.
Found this great instruction to burp https://reischeperformance.com/refill.html AND I cannot find the crossover plug to do it.
Already tried this https://www.f150online.com/forums/19...nt-system.html
It worked until I opened the radiator to make sure level was good and be done with it. Then gauge shot up again.
Have been looking all over for a picture of the crossover plug and finally just made account and asking.
PLEASE SOMEONE TELL ME WHERE IT IS.
Thanks.

 

Welcome to FTE.
When was the 4.6 DOHC (first link) installed in your truck?
2nd link is also for a 4.6 what year & motor is in your truck?
You are in the 1980 to 1986 truck area so you maybe asking in the wrong area?


What helps is drilling a small hole of the tstat to let a little water but the air pass thru it.
But to help get the front of the truck up as high as you can. Motor cold remove the radiator cap, top off the radiator, start motor heater on hot low fan and let it idle to get up to temp. As the tstat opens air will come out and you can top off the radiator.
Keep doing this till it will not top off any more.


Put the cap back on radiator fill the over flow container and you should be good.
Dave ----

 

Thanks for reply. That is the reason I am asking where the crossover plug is on THIS engine...because the engine in the picture is not the same as this 86 Ford F150 4.9.
Am thinking the procedure sounds good to follow since after doing what you suggest, the standard cap off, run with heat, top off (minus drilling a hole the thermostat), and we still have an air pocket.

I did this yesterday from the second link "Open the degas bottle, run the engine to closed loop and heater on max. As the thermostat opens, use a shop rag and squeeze the water return pipe. Air will escape out of the degas bottle," After driving around throughout day, it appeared to work. Gauge was staying just left of middle. Thought it was solved.

Then mistakenly when home for the day, I opened the radiator to make sure level was good to "be done with it" and it boiled over. Lost fluid and the pressure in the cooling system that had settled into working got all wonked up again. Back to running high.

Today did some driving and tried again. At first, stayed way high up to the L (of NORMAL). Could see air bubbles coming out in the overflow tank when squeezing the water return hose. Hoped it was working, but kept running high. Just before home, appeared to drop back to middle. Have not driven again yet. Am thinking if I can find the crossover plug and properly fill from there as first link with Ford instruction said, this monkeying around with getting the air out could be done.

Here is a picture of a plug right near the return hose on the thermostat housing (gooseneck) that I am wondering if that is the plug?

 

Your 4.9 inline six has nothing considered to be a crossover plug. You are reading something intended for a 4.6 modular V8.

I don't think your overheating issue is due to any sort of airlock.

 

As far as I know I have never seen or heard of a "cross over" on any of the older motors (to mid 80's any way) be it a L6 or v8 to have one.


ONLY open the cap with the motor/cooling system cold.


As I posted get the front of the truck up as the high point so any air will exit to the radiator.
Then run to get motor up to normal temp topping off the radiator as needed. Temp gauge should read in the middle as normal.
Before shutting down the motor put the cap on and fill the over flow.


I have not filled my cooling system as I may need to pull the radiator to install the AC condenser but the way I posted is the way I will be doing it.
Dave ----

 

I have given that some thought, bad head gasket?
Was the motor over heated before doing the pump & stat?
Or why were they changed?
Dave ----

 

Since the problem seems to coincide with pump replacement, I'll ask exactly what year truck are we dealing with? Specifically, pumps for V belt vs. pumps for serpentine rotate in opposite directions. Are you sure the correct pump was installed?

 

Ford's way to burp your cooling system!!!!

Here is a more simple list of what I am thinking would work if I can find out where the crossover plug is.

I took this picture wondering if this may be it. I thought it would be on top not side though.

 

You appear to have multiple threads going here.

Probably not the best way to get a clear answer.

https://www.ford-trucks.com/forums/1...d-coolant.html

 

On my trucks with the 4.9L I6 engine, I take off that heater hose(just left of your arrow) that goes to the thermostat housing while filling up the radiator(put heater hose up high). Once the engine block/head are full, coolant will come out. Reinstall the heater hose and start up engine like others have said.

There will be air stuck inside the upper radiator hose till the t-stat opens up and flushes it into the radiator. Add coolant as needed.

But for the most part the engine should have little to no air inside with that refill procedure.

As your truck is a 86 most likely with the feedback carb and V belts, make sure you did get the correct water pump. On EFI 4.9 engines the water pump will run backwards to the V belt NON EFI trucks.

 

1986. And yes correct water pump. Actually appears not to have needed it upon inspection of the old one.
Truck has been running fine. Monday on usual drive to work gauge read to the right of center vs center as usual.
Could smell hot antifreeze. Did not go any higher than the M.

Got some antifreeze to top off. Only took a small amount, so okay not just a fluid issue.
Got a thermostat. Old one was not stuck shut. Still put it new and new gooseneck/housing.
Mechanic did not burp after this repair. Still ran high at the M.

Mechanic said water pump then. Installed new water pump. Upon inspection, old one did not appear to have any damage (spinning freely, blades fine)
Again did not burp. Still ran high up to the A now.

Seemingly out of order, mechanic now said flush radiator and check temp sensor.
Flushed radiator then decided to get new one as testing old and flushing after removal was close to price of new.
Again did not burp. Now ran high all the way to L.

Mechanic said new temp sensor. I said not needed, it was clearly truly running hot per air from heater. He put one on anyways.
Still running high.

EXCEPT after the water pump on drive home, stopped at bank, got out, got back in and gauge was NORMAL.
then yesterday after burping effort with overflow tank open and squeezing the return hose few times over the day,
went down to left of middle between O and R and rode there all rest of day. Solved! Yes!

Until I mistakenly opened the radiator cap before fully cooled and apparently disturbed the pressure/let air in again and lost the solution.
Trying again today....last check it was back down to smack dab middle, but haven't looked again. Thought the reische post may be what I needed, to fill with a funnel, etc as it seems pretty clear there is air in the system. When it gets moved, the temperature is perfect as the cooling system is circulating. Then if the air pocket there zero coolant circulating and hot, hot.

Earlier today pulled over when it was going up. Squeezed return hose and saw the bubbles coming up in the overflow tank. Got back in and it was down to middle.

 

All of this seems to start when your mechanic told you that you needed a water pump. What you have not told us is why you went to the mechanic. Was your truck overheating prior to replacing the water pump?

All that you have replaced to date has not solved your overheating problem. It would be logical to presume the cause is something else. Are there bubbles in your coolant? So far, nothing is ruling out a head gasket problem.

 

I merged the two together. Yeah, the initial question now shows up twice, but just ignore that.

 

thanks for thoughts on this. apology for any inconvenience on repeat post. was hoping to resolve today to have running truck for work in the morning with simple locating of crossover and didn't know if someone who knew may see it in one of the threads. sounds like one post advised, so got that now.

re water pump reason as said above - Truck has been running fine. Monday on usual drive to work, gauge read to the right of center vs center as usual.
Could smell hot antifreeze. Did not go any higher than the M.Got some antifreeze to top off. Only took a small amount, so okay not just a fluid issue. Tstat?

Got a thermostat. Old one was not stuck shut. Still put in new and new gooseneck/housing.
Mechanic did not burp after this repair. Still ran high at the M.

Mechanic guessed then that it could be water pump. Installed new water pump. Upon inspection, old one did not appear to have any damage (spinning freely, blades fine) Again did not burp. Still ran high up to the A now.

SO it may have been thermostat, but air in system post repair made for continued running hot.

Again I am guessing air in system because I get a fully normal reading suddenly a few times immediately after the repair and yesterday after the effort to bleed air was back to fully normal. The reading was actually lower than prior to the cooling system r and r's as one may have expected. It read left of center all day with long trips around town. No overheating or hot reading. as said, " yesterday after burping effort with overflow tank open and squeezing the return hose few times over the day,
went down to left of middle between O and R and rode there all rest of day. Solved! Yes!

Until I mistakenly opened the radiator cap before fully cooled and apparently disturbed the pressure/let air in again and lost the solution."

am going to try the heater hose remove and fill tomorrow, Eddiec1564, when cold at start of day. did do a last trip tonight to see if perhaps it was resolved again before messing with the hose and was back up to A. also will double check the water pump part number. thanks again