Cooling system pushing out coolant

[MMiller]

Hey guys, I need some help. Hooked up to the trailer today, loaded up my 75 Dodge to go fourwheelin @12,000#. Headed out in a 15mph head wind, put it in overdrive set the cruise 70 mph, ran steady 25-30 psi of boost, and 1100-1300 degrees on the pyro, just like the last 20 times I went out to play. Pulled off the interstate about 40 miles later. Pulling away from the stop sign looked down and saw the engine coolant temp gauge pegged. Got out and found the expansion tank full and overflowing a little in to the enging compartment. Took the cap off the radiator, which was cool, as was the top radiator hose. The coolant level was low in the radiator. Added 1 gallon of antifreeze, and 1/2 of water. Engine temp cam right down. Put on the cap and the top radiator hose sucked shut. Took off the cap and it quit. Temp was normal. With radiator full drove the last30 miles of 2 lane at 55-60 with no problems, not overheating.



Went and played loaded up to go home. Had to add another couple of quarts. Checked the oil, no water, same level as the morning. Started the truck, idled fine, no white smoke. Drove home the same trip. Stopped several times, changed the radiator cap, ended up needing to add about another gallon on the way home.



The truck is not running hot as long as there is coolant in the cooling system. All the coolant is coming out of the overflow on the expansion tank. This is the first time in 200,000+ miles the expansion tank has actually gained coolant. Stat seems to be working fine, as does the cooling system. As you can see, switched out caps off of my 75, just to see if that was the culprit, did not seem to change perfromance. For some reason the radiator is pushing the coolant out, but not pulling it back in. The head gasket is about a year old, with prolly only about 10,000 miles on it. Done alot of towing with the truck this year, never got it hot until today.



Does anybody have any ideas? I am coming up blank, not wanting to think the head gasket is blown.



Sorry for the long post, just wanted to get everything down for you guys.



michael

 

[dagger]

coolant system pushing out coolant

either you have a leak in the cooling system that caused it to go lowand over heat which will force coolant into over flow bottle,or a restricted radiator or possibly a cracked head or gasket. i would replace the thermostat first due to the over heating. when the hose sucked shut it was the vaccuum in the cooling system trying to draw coolant out of the bottle. chech to see if the drip hole in the bottom of the water pump is clear of crud. sometime these things plug up and dont show the leak. you will need a mirror and flash light to see it. when my 91 pushed coolant out of over flow tank it was a crack in the engine oil cooler that pushed oil into cooling system which was about 8 quarts low by the time i realized what was going on. over flow fills with oil after antifreeze is gone

 

[csutton7]

well when I blew my head gasket it did this same thing, so I'm thinking this could be what's causing your prob, but first check buy a new rediator cap and then check the thermostat and see if it's working right then after that go drive the truck and keep the boost at 20lbs if you can and check the level, then drive it at 30lbs and check again--if it is ok after the first run but not the 2nd then I'd say you probably have a blown gasket---hope this helps--chris

 

[JLEONARD]

buy a new rediator cap

I agree. Has solved similar problems on other vehicles in the past

Hope it's that easy.

Jay

 

[Snow man]

if the rad cap dont do the trick you more than likely need a head gasket .

 

[Greenleaf]

I have had to solve many no. of coolant problems over the years. The hose collapsing is two fold. The thermo closed and you run the engine up which in turn allows pump to pull the coolant out of the upper radiator. I see this all the time when working on the 5. 9 in my buses. I have that little coil spring inside upper hose wear through the side of hose The other thing is the cap will not allow coolant to siphon back into the radiator when the temp drops and system forms a vacuum. This is usually due to a cooling system leak as air is pulled into system through leak instead of coolant from bottle. You may have a leak in the bottle hose too.



When coolant is pushed out it is warm (heated) coolant expanding or possible engine compression from a leaking gasket. I see a good no. of farm tractors pushing coolant to reveal a gasket problem/head problem



Sorry soooooo long, just wanna help.



Scott

 

[Bob Beauchaine]

I've got to go with most of what's been said here, I would suggest that you remove the radiator cap make sure the radiator is full then start your truck. If it's a head gasket you should see the coolant start to developer bubbles fairly quickly,if not right away. If you do you've probably got a head gasket leak.



Your EGTs are right on the ragged edge even if your pyro is pre turbo. Here are the "if" suggestions. If it does turn out to be a head gasket and if there is no damage to the block or head you might want to consider using Old Smokys eccentric. I have seen 100 to 150 degree drop in EGTs with it being the only change. On the other hand if your pyro is post turbo I'm surprised you haven't had problems sooner.



Bob

 

[MMiller]

Pryo is pre turbo- yeah I know I'm on the edge. I would have thought that I would have had troubles this summer pulling larger loads, with a/c on etc, and was on longer trips. Thanks for the help. Thats kinda the track I was on, hoping for the easy fix, but prolly not gonna get it.



Michael

 

[BushWakr - RIP]

Yup, and what ever you do, don't let the pyro hit 1800*F like some other maniac/lunatic canadian did... .



Pastor bob... . "thermally challenged in Canada... . eh! "

 

[JLEONARD]

don't let the pyro hit 1800*F like some other maniac/lunatic canadian did... .

Possibile explanation for the unusual weather pattern the past year in the eastern US? I think we're on to something!

 

[redmule]

you may want to check the cooling fan clutch, as it could be part of your problem. I go with Bob, blown head gaskets will show as bubbles , also you may smell the order of anti-freeze in the exhaust fumes and water or anti freeze will appear as white exhaust in a severe brown head gasket to the cooling system

 

[MMiller]

Talked to Nascar Mark the other night, thank you Mark. We talked in extent about how I repaired the head gasket last year. Also talked about not letting the truck warm up before taking off. I admit a couple times this winter I started the truck and after oil pressure slowly took off and took it easy, as many guys on the TDR say they do, but I belive that contrubited to part of the failure. Mark also said to mill the head which I did not do the last time. I checked it with a straight edge and was happy, but he reminded me my truck is not stock and . 003" might work on a stock motor but not a 30psi boost motor. He reassured me that if repaired right the stock head gasket will work in my application, don't need orings, still thinking about the stud kit though. I will at least put in new bolts. Thanks again Mark and PDR.



To add to the story I filled the radiator today and turned the engine over, no hydro lock, so I started the truck, no white smoke, ran fine. Let it idle for 15 minutes and got bubbles every 10 seconds or so in the bottom of the expansion tank. Took off the radiator cap, and had a consistent large bubble come to the top. I guess its time to pull the head, and hope that its not cracked.



Thanks for all the help guys, this time I will do the repair a little better, keeping in mind the old girl runs to good for stock specs sometimes.



Michael

 

[nascar mark]

Its a good idea to make sure you have 140 degs into the engine before you build boost over 10 psi if you want a head gasket to survive.

If you have to do a head gasket, making sure the head and block are straight and clean to do the job right.

The head and block will have wear marks were the head gasket fire rings were. The head takes the most damage from the fire rings because of expansion and contraction and in extreme cases, leaves nasty grooves as deep as . 016" even after 40,000 miles. I send out every head to be decked and make sure the block is worked over with emery paper on a block to clean it up. Clean all surfaces and threads, change out the 2 block dowel rings with new ones is also important. Check head bolts for stretch and change out with new ones if out of spec. Even better would be head studs for better clamping force and more accurate torquing of the head. Make sure you apply a light coat of proper lube to the treads of the head bolts or studs before torquing. Now your good to go.

If you are going to be running more than 45 psi of boost pressure, then I would either have the block or head o-ringed to hold the higher pressure in, unless you like doing head gaskets.

 

[MMiller]

Just to update everybody. Last weekend I started the truck and found bubbles in the radiator.



Today I pulled the head off of the old girl to have a look see. As I was removing the head bolts, THREE of the short bolts came out VERY easily. I kept track of the them and sure enough the head gasket was leaking right beside one of the loose head bolts. Combustion heat was escaping and disentigrated the rubber seal around the hole for the coolant passage. Now I know for sure thats were the extra pressure was comming from. Head did not have any obvious cracks. It will go in to be checked this week and milled if it isn't cracked.



I did not retorque the head bolts after the repair about a year ago, I just went with the instructions I had at the time. I will be contacting PDR again to get the low down on how they do it when I am ready to go back together. I am now seriously considering the PRD stud kit, maybe cheap insurance.



Thank you for all the help and I am sorry for such long posts.



Michael

 

[Bob Beauchaine]

Sounds like the best of a bad situation. I am glad to hear that it was the easiest of possibilities. Good luck and keep us posted on how it finally turns out.



Bob

 

[R.E. Miller]

I think that re-torqueing the head bolts really becomes an issue when you are over "stock" hp levels. I have done a fair amount of head gasket jobs, and had no trouble with come backs, but all of those jobs were on stock engines.



Russell

 

[MMiller]

Well guys got some more news. I picked the head up from the machine shop on Wednesday. NO CRACKSOo. They had to remove . 010" to get it flat again. Hopefully can get the rest of the parts tomorrow and maybe start assembling saturday. Can't swing the studs at this time so I will be replacing all the head bolts.



Once again thanks for all the help. Also lots of thanks to Mark at PDR for talking to me again.



Michael

 

[MMiller]

Bringin it back to the top again.



Just to update everybody again, one week ago today I got to install the head back on the truck. I cleaned it all up and started assembly. Got it all back together and started the truck. Let it warm up and had no leaks, no bubbles. Let it warm up to operating temp and shut it off. Changed the engine oil/filter. Went back monday night and torqued the bolts one more time, then re adjusted the valves. Put on the v/covers and drove it home. Made about a 500 mile trip last week and a 300 mile trip last night, with several 30 psi assaults. Seems to be running good and no lost coolant.



It was sure nice to hear the pipes again, and as always it puts a smile on my face everytime I drive it.



Thanks for all the help.



Michael