i hate my truck.....
 

a couple nights ago i went out to adjust the valves and got it runnin decent so ran it up to like 2 grand for a little bit to warm it up good then let it idle at right about 1050-1100... it sat there for a while then it stalled and right after it stalled...the bottom radiator hose comes flieing off shooting however many gallons of hot antifreeze everywhere. what would cause that? i know the clamp was on tight because i checked it a couple nights ago. every time i fix one thing another one sh#$s out. im about ready to do this to it.

Thermostat never opened?

it dont have one.....and the coolant was just barely hot enough that i wouldnt stick my hand in it for a while....i could touch it for a little bit though.

Yeah, sounds like a cooling issue to me. Thermostat is the first to look at, maybe a 37 year old radiator, maybe crud in the water jackets of the block, maybe the water pump...

400 small blocks run a little hotter anyway because of the siamese cyliders.

You could ship it to me and then you wouldn't have to worry about it anymore! ;)

Hmmm, I know that you said it was tight but the only thing that would make it come off like that is it wasn't tight enough. I can't think of any other reason.

Oh, didn't see your last post, my first guess would be a bad fit on the hose. Maybe it's a little big and even though the clamp was tight, it wasn't actually tight. Maybe the hose is too short and the tension pulling on it helped work it off...

Just where I'd start.

is it a new clamp?
if not put a new one on.

Could you have blown a head gasket? I wouldnt think so, but i know some bigger engines will blow the radiator hose off when they break a head gasket internally.

(quote) I hate my truck.. Sir put the wrench and hammer down and step away from the truck! Sir I said step away from the truck! j/k Hope you get it figured out. I would think that it takes a good bit of pressure to just blow a hose off. Why did you need to adjust the valves? Was it running real bad? Did it start running bad all at once? Is there a chance that it blew a head gasket and is pressurizing the cooling system?

I was thinking the same thing as stelth, I had a cougar that did the same thing, blew off the lower raditor hose,, then the raditor blew a leak,, finally found out it had a blown headgasket,, (it really didnt blow white smoke out the tailpipe till later),, the pressure of the leak blew off the hose, parked it now the engine is water locked...

here it is the head gaskets are new......everything except the block is new.

Personally I never could get them tight with a screw driver always use a ratchet and never had a problem. I would turn them tight as I could with a driver and the ratchet will always get them tighter. If the head gasket went I would expect it to be hot even with out a thermostat, and I would expect it to blow when he had the rpms up on it. Put it back on and run it again and see what happens. With no thermostat it will never really heatup around here.

With no thermostat will cause overheating on some engines due to coolant flowing too fast to cool off in the radiator. I would suggest installing one correct for the season.

when i did my engine swap i kept getting leaks on the lower hose, w couldnt get the worm drive style rad hose clamp tight enough, i striped out 2 of them. then i went to napa and got s different style and the problem was gone. i reefed the $h!+ out of them and no more leaks, something you might want to try

well i think it's the head gasket.....it ran like sh@% blows smoke and has pressure in the hose.....i tried to get that rad hose off for like 35 minutes the other night....i pulled it yanked it tried twisting it used a screwdriver a hammer everything and it wouldnt budge so i said screw it and put the clamp back on. then it blew itself off...the fin truck hates me.

I was thinking the same thing,I hjad my old Nova shoot the bottom hose off like that.I double clamped it,and it wold blow water about 4 feet out the top of the rad with the cap off.
It had a blown head gasket.On a good note,both the heads,and block were in fine shape,and didn't even need surfacing:D

the heads have been decked already and the block is a virgin block in real real nice shape so i should be good for that....how much do 400 head gaskets run? anyone know? it's been a while since i bought these. this kinda pisses me off though...:'(

i bought mine for $16.95 a side (felpro) might be a dumb question, but, are you sure that the head gaskets were for a sb400 and not a 350, cause then you would block the steam holes, but i think you knew that iirc from other conversations

With the information given,my guess is that Mike Files is correct.

Ahh yes, Our trucks, it is a love hate relationship.

Sorry, I have no advice. Just listen to all the guys above, at least they know what they are talking about. :D

the temp has nothing to do with it....as i said before i could stick my hand in the coolant......it wasnt that hot. im sure they were 400 SB head gaskets yes....i have a set of 350 ones here still...you know i am in school to become a technician and i built this all from nothing and know a lot about this.....and i noticed the white smoke but it never crossed my mind. i feel so stupid right now.

It all good man,Money will fix it:D

also the other night i ran it for maybe a minute tried taking the cap off and there was a SH%$ load of pressure in there....finally got it bled off and tested the antifreeze and when i sucked it up it was completely white from air bubbles.

Ok! Now that I see you have a 400 and that you said you had 400 head gaskets. Do you have 400 heads or did you have the steam holes drilled into the heads if they are not 400 heads? A 400 has such a small area between the cylinders that the gaskets are thin and blow easy when the steam holes are not present. I have had to drill the holes in heads by using the gasket as a template and center punch the holes then carefully drill them out. I don't remember the size of bit that I used.

Just done a Google search for (drill steam holes 400 heads) and came up with the drill bit size for the steam holes 1/8" This is a common mistake when someone bulids a 400 because people are told all their live that a small block chevy are all the same and they forget about that "BIG" redheaded bastard stepchild of the small block family, the 400.