Hi everyone; I've got a 66 and it keeps blowing the top rad. hose (3 times) the neck is calapsed a little and not real good and round I didnt know if that will hurt it or not, Today I put new hoses top and bottom and a new termastat and took it down the road about 10 mile and it blow again , and I dont see any water in oil at all. Thanks Rod

 

Is the thermostat spring end pointing towards the inside of the engine ??? Is the radiator getting good flow??? Let it cool and crank it up with the cap off and see what happens...
Whats the shape of the heater hoses???? Is the water valve on or off???...heater core plugged ??? What psi is the radiator cap rated at ???

I will look up the specs for that and let you know what I come up with...what engine is in the 66 ??? also, is there a coil spring inside the bottom rad. hose..there should be...prevents collapsing...

One other possibility is that you arent bleeding the cooling system after servicing...you gotta run it until the t/stat opens fully and THEN you burp it...you do this with the cap off...you will lose some water during the burping process unless there is so little water in it...
As for the cap...I didnt see anything in the shop manual about cap pressures for gas engines..only diesels...
In looking at the parts catalogs, there 2 possibilities...7 pound cap or a 13 pound cap...My guess is one is for the higher altitudes but thats strictly a guess as Im at sea level. When you run it check to see that the radiator is getting evenly heated...no noticably cool areas in the core...check this when its up to temp...you gotta snake your hand between the grille and radiator on the forward facing side of the radiator core...be cautious though as it will be hot...any cold spots when its up to temp and burped is a plugged area or an area thats plugging...If it had nasty coolant to start with a flush is in order IMO...
The radiator cap pressure rating is stamped onto the cap itself visable with it installed...ideally get a lever type cap to safely release pressure. Also, any time you take the cap off of the radiator while hot...throw a rag over the cap...a big one ideally...and think material ...IF you MUST take the cap off while at operating temp...otherwise wait for it to cool down...still use the rag over the cap though.




Keep us posted on your progress


- cs65

 

The caps that came standard equipment on these trucks when new were 13 lbs.

With a release handle (C1UZ8100A), or without (B8A8100A r/b C9AZ8100A) were available.

Radiator caps usually have the poundage marked on them.

When the cooling system aged, some ppl used either a 4 or 7 lb. cap.

 

Hmmmm, rad hose collapse, assuming the oil is okay; not cloudy, may want to take a compression test. Suggest check water level after episode and see if radiator water level remained the same. Had an experience with aftermarked thermostat housing with the o-ring seal leaking causing the engine to overheat. Could not fiqure out where the water went, assume due to evaporation from overheating. As Bill and CS mentioned, faulting rad. cap can cause overheating, and on 1 occasion installed a faulty, newly purchased thermostat, now place them in pan of water and check temp when fully open. Would be interested in what you find.

 

Well I think I found the problem, Today I fixed blown hose and burped the system and it burped three times let it set and idle with the cap off for 45 min. and everything looked good so I put on a new cap and felt good about it , so I went for a stoll and no problems. And my immature side started to come out and I held the brake to smoke the tires and it blow again. So I limped back dried off rad. hose and my eyes and started to study things, and came to the conclusion that it might be a busted motor mount letting the motor raise and close that 1 1/2 gap between hose and fan blade. Because yesterday when it blow it was under torque also, so a put a pry bar under driverside motor mount and could raise motor about 1 inch. So I think thats what my problem was Thanks for your help Rod

 

wow...sounds like a good reason to not roast the tires...I remember last year going for the inauguaral run in my friends hearse after bringing it back to life...around town...no problem...went on the freeway...did really good until almost at the exit ramp...the fan sucked the upper hose down into it and even with the shroud on it put a nice wear mark on the hose...theres a clamp that goes in the middle of the hose that got misplaced...and later found...it supports the middle of it to the core support...
its weird how air and do things that cause hose problems in the darndest ways...Hopefully the mount will fix the problem...and if both are original mounts I would replace the other while you are in there...


- cs65

 

Wow, engine mount; who would have thunk. Hopefully the problem, just not sure.

 

Here is a FYI if you ever get stranded and don't have a replacement hose. It doesn't pertain to the thread a lot other than it being a hose .You will be glad you read it if you are in the middle of nowhere and have trouble. I had it to happen to me. Anyway I was out in a small town to get some stuff and the truck got hot so I pulled over at a parts store. It was a hole in the top hose. I went in and asked if they had a hose,yeah sure. They didn't and I was an hour from home. He told he had the hose clamps and I could go over to the muffler shop and get a 6 inch section of pipe. I went and got a 6 inch metal muffler pipe and cut the hose pipe apart at the split. I put the metal pipe in the rubber radiator pipe and put clamps on. It lasted at least a year or two until I found a pipe. It worked great. So remember that if you get stranded.

 

WELL IT WORKED i replaced the motor mount and it fixed the problem Rod

 

Did you replace both sides ? :-)

Might as well...if one was bad...the other got stretched more then designed...plus could be oil soaked and soft as overdone spaghetti...



- cs65

 

CS65,
The RH (passenger's side) motor mount would be in compression when the engine is revved; so I doubt it was stretched out of shape.
Although your suggestion still stands, as it may very well be oil-soaked and deteriorating......

BarnieTrk

 

CS65,
The RH (passenger's side) motor mount would be in compression when the engine is revved; so I doubt it was stretched out of shape.
Although your suggestion still stands, as it may very well be oil-soaked and deteriorating......

BarnieTrk