I’ve posted this on an F150 forum that I’m a member of but I know we’ve got a few mechanics here…
1998 F150, 4.6L V8. I’m changing out the upper and lower radiator hoses since they are getting soft (just rolled past 100k miles).
When I drain the coolant from the little outlet on the radiator I only get about 2 gallons out. I was unable to open the engine block coolant plug (located underneath the truck, a couple of inches over the oil filter) but Ford’s documentation says that there should only be about a liter of fluid behind that.
Flushed the system by running plain water through it, then added some radiator cleaning stuff, topped it off with plain water, sealed it up, brought the engine to temp and ran the heat full blast for a while to see if it dissolved any crud, suddenly let me drain the whole thing, etc. No dice, when I drained it a second time, still get 2 gallons out. I measured how much water it took to fill the reservoir to the right mark and it’s 2 gallons. Drained fluid looks fine - not filthy with rust or anything. Truck hasn’t had any cooling problems, last time I had it flushed and filled by a mechanic was just about 2 years/15k miles ago.
Am I missing something simple? Do I have to just get under there with my breaker bar and a 5/16" allen-head socket and open that coolant plug (I understand they red loctite it shut, probably why I had such a hard time) and that’s where the last 3 gallons are hiding? That seems like an awful lot.
BTW the collant capacity is supposedly 19.4 quarts, just under 5 gallons, according to my Chilton book.
Work being done on a pretty level surface. Got it filled with tap water right now, but once I can actually flush and drain all 5 gallons (or close), I will replace the hoses and use proper coolant and distilled water to fill it back up.
I ran into the same thing. What I did was drain what I could and fill it with water, then run it for a day and drain that. Did that 3 days in a row. When the thermostat opens, the water in the block mixes with the fresh water in the radiator and gets diluted. After 3 dilutions, it was running pretty much clear so I dumped a gallon and a half of anti-freeze in there and mixed the other half gallon with water as a top off.
Thanks Duke. I think I’m pretty much on that road simply by dint of the normal flushing routine (drain what I can, fill with water, run for a while with heater at full blast)…however since I’m changing the hoses I’m wondering if I’m going to spill 2 or 3 gallons of stuff all over the place when I take them off after the final draining.
Plan B is to drop it off at the mechanic with my parts and have them do it but I like to handle what should be a straightforward task myself…
You might need to take a heater hose loose to allow air into the top of the system. Easier, and better yet, install a back-flush kit. (from any automotive store) Also a good idea to vent the high point when you refill the system, as many will “air lock” which can lead to cracked heads.
I find it hard to believe there’s only a liter of liquid being held by the block drain plugs. I routinely remove them on various engines and find quite a bit more comes out.
The ideal thing is to indeed remove the block drain plugs. As it’s a V-type engine, it almost certainly has one on each side of the block. The two problems in removing them are access and tightness. Often one or both are obscured to where a fair amount of work needs to be done to get to it at all. And even when accessible, they’re often so tight as to defy getting enough leverage without the socket slipping out of (or off of) the plug. If you can safely get a torch on the plug, heat it red hot and let it cool. This will negate any Loctite and should make it easy to remove.
If you can get both plugs out, great. If you can only get one, good. If you can’t get either, you can still flush it, it just takes longer. Use a garden hose so you have flow, and disconnect a heater hose at one end. Flush through both the hose and the fitting you took it off of. If you got a plug out, install the radiator cap and flush both directions again. Then remove the radiator cap, close the radiator drain, temporarily reinsert the block plug(s) and flush again both directions so the water comes out of the top of the radiator. When only clean water is coming out of the radiator drain, the block drains, and the top of the radiator, it’s well flushed and only water is in the system. Open all drains to get out as much as possible.
If you can apply air pressure to the hose and its fitting, you can force more water out. To do this, install the cap, plug the fitting with a finger, and blow air into the hose. Then plug the hose and blow into the fitting.
Replace/close all drains and reattach the hose. Add 10 quarts of pure antifreeze. If the radiator gets full before that’s done, bleed air from a high point on the system (usually a heater hose connection works fine). Top off with water. Fill the overflow jar 3/4 or so full. There’s almost certainly some air trapped in the system that will burp out, with liquid then being sucked in to replace it. Watch it carefully for a few heat/cool cycles to make sure the air gets worked out. At this point coolant will be up the top of the radiator (check with COLD ENGINE ONLY) and you can fill the overflow jar to its prescribed level with 50/50 antifreeze/water mix.
Thanks everyone. Based on all this, response at other board and talking it over at lunch with a friend who does much maintenance on his own vehicles, I’ll install the little $5 flush/fill kit on the heater hoses and run plain water through until it all runs clear. Friend recommended replacing the thermostat when I’ve got the upper hose off and suggested taking the old thermostat out before doing the final flush, that will allow plain water to flow through that path without having to let it heat up enough for the thermostat to function.
Then drain as much as I can (Gary, I’m not comfortable going at the bottom with a blowtorch so I think that those plugs are staying in place)…any reason not to leave the radiator petcock open and turn the engine on briefly to aid in the final draining? Replace thermostat and upper/lower hoses.
At that point should have about 50% capacity filled with water, 50% air. Top off with coolant, let it cycle, check with hydro gage to see if I’ve got correct density.
I don’t trust flushing tees. If you open up a heater hose (either by disconnecting it, as I suggested, or by cutting it in two for a tee installation), you can flush in two different directions. One is back to and through the heater, the other is toward the engine. If you flush in either of these directions and don’t have too much drainage elsewhere, the flow will come out of the other direction’s opening. But using the tee, you’re flushing in both directions at once. The flow from one direction will meet and possibly block the flow from the other direction, and might prevent either flow from fully cleansing the system. Not to mention that the tees (plastic) break fairly often.
Now, I know plenty of folks use these tees, and seem to be happy with the results. My position is that it’s just as easy to disconnect the hose from a fitting and flush through both of those, and when you get flow out of the other opening you know you’ve cleaned something out.
I don’t think the water pump will help with draining. It sucks water in from the lower hose and pumps it up into the system. You want stuff to drain down out of the system.
If you don’t have any block drains open, you’re likely to have the system more than half full of water (remember, you only got 40% of it out by draining the radiator). If you don’t have compressed air, blow it out with your breath. That’s less of a pain than having to drain off some 35% antifreeze/65% water mix in order to end up at 50/50 (which includes using algebra to figure out exactly how much to drain out).
I worked at a radiator shop years ago and we routinely backflushed the engines with 90 psi of air and had no problems. After flushing out the gunk, we would turn off the water and blow out any residual water from the block. I made my own backflush tool and it works just as good. The easiest way is to remove the thermostat, reinstall the housing and upper hose and blow air into the upper hose. Depending on what you are using to blow the air into the engine, you may need a rag or two to seal off the upper hose. As long as the lower hose in not attached to the radiator and there is nothing blocking the water passages, you can’t hurt the engine or heater core. If the thought of using compressed air makes you nervous, a shop vac to either suck or blow out the residual coolant will work too.
Well I was thinking of using the little safety air nozzle with my compressor but I had wondered about my shopvac…just got one of the new ones that has a blower output so perhaps I’ll give it a go. Also got an adapter so that I can put my 5/16" allen “socket” on my big breaker bar and I’ll see if that will open the drain plug underneath.
Got the upper and lower hoses free, ran water through.
Decided to try opening the coolant plug on the driver’s side. Theoretically it’s in there with red Loctite which according to the tube I looked at at the store can take about 200 ft-lbs of torque so I was prepared for a struggle.
Worked slowly, felt it “give”, then removed the plug.
Nothing came out. Hm, that’s odd. Shine a light up there and the hole is blocked.
My coolant plug sheared off. I have a piece of it about 1/2" long on the end of my ratchet.
Now I’m no professional mechanic but this would appear to be a Bad Thing, or at least a Bad Thing that I can’t fix.
GaryT since you’ve been the voice of wisdom on matters automotive, I assume that I can go ahead and finish putting my hoses (and new thermostat) in place but fixing the plug will require a shop to put it up on a stand, drill out the bad plug, repair the hole and put in a new plug. No sense changing my coolant, since they’ll have to drain it anyhow.
On the face of it this seems like it’d be a pretty simple procedure (just not one that I can do myself), what do you think?
Congrats!
For future reference when properly applied red Locktite is stronger than a grade 8 bolt. Try unscrewing it and it will take the threads right off of the bolt. :eek: Or break the bolt off. :eek: :eek:
Don’t ever use red Locktite if you think you might maybe ever want to take it apart again.
What am I harming by disconnecting the upper hose, having the heater on and running a water hose into the radiator keeping it just full enough to no run out the upper hose port and letting the running engine pump clean water all through the system? When the water coming out the upper hose is clean, I figure I have gotten all the old coolant out and then add the recommended amount of straight coolant to get my 50/50.
Working with a cold engine and the thermostat out, what am I harming? Anything? Not a good method? If not, why not?
Thank god someone messed up on mine then There was a touch of the stuff on the very last 2-3 threads, and I think at least one was partially exposed anyhow (the plug is slightly tapered towards the inside of the engine so you can’t get it all the way flush).
I reinstalled the plug with teflon tape on the threads - seals it but I can get it out again.
Looking at the Loctite website all of the medium strength threadlocking products are blue.
Thread sealant products are either white, yellow or brown. (All the common ones you would find in local store are white)
Only the permanent strength threadlocking products (262, 270, 271, 272, 277, and 2760) are red.
Unless you can find a product that they don’t list in their website, I think you are incorrect about this.
The only saving grace for people that buy red Loctite and have to then disassemble the joint, is that they probably did a piss poor job when they applied it. As a result it is no where near as strong a bond as it should be.
Trust me when I tell you that it is stronger than the material it is applied to BTDT and got the T-shirt to prove it.
I may be wrong. I was using their website as my resource - and what a godawful pain in the neck travesty to navigate that website is - and didn’t find anything specifying the color of the product, so I assumed it was indicated by the color of the bottle. These removable-strength products come in red bottles: 222,242,243. Did you find something that clearly indicated the color of the actual product, with it sometimes being different from the color of its bottle?
I don’t doubt that, particularly if the wrong product was used (designed for a larger diameter bolt - they actually specify that on at least some products). But I have personally used red Loctite to assemble some things, and later removed the bolts without undue effort (though certainly more effort than without Loctite), much less breakage.
I still believe that “red” is too broad a category of Loctite products to make meaningful statements about, but I’d be interested in any further info.
There was a touch of the stuff on the very last 2-3 threads, and I think at least one was partially exposed anyhow (the plug is slightly tapered towards the inside of the engine so you can’t get it all the way flush).