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Well, 90% certain my head gasket just went
https://www.slantsix.org/forum/viewtopic.php?t=67858		 Page 1 of 1
Author:  ScottJ175 [ Tue Jul 30, 2024 5:11 pm ]
Post subject:  Well, 90% certain my head gasket just went
Fired it up to work on tuning the carb and I start to notice leaks at my newly installed water pump and water outlet. Then I give the upper hose a squeeze and it's rock hard, ditto the lower. Much harder than when I ran it for 20 minutes last night.

So now I have to decide do I just get another used running 70s 225 and drop it in or do a head gasket. Head set is $66.79 at Rock Auto and I have a friend who owns a machine shop that might give me favorable pricing on checking/cutting the head.
Author:  volaredon [ Tue Jul 30, 2024 6:50 pm ]
Post subject:  Re: Well, 90% certain my head gasket just went
That seems high for a head gasket especially being most likely from RA is either mahle or fel pro.
If you pull the head have them shave at least the difference between the original head gasket and the replacement (of it still has the original HG I guarantee the replacement will be thicker which will lower compression.
Author:  Reed [ Wed Jul 31, 2024 1:33 am ]
Post subject:  Re: Well, 90% certain my head gasket just went
I would do a bit more diagnosing before I concluded you had a blown head gasket. Run the engine with the radiator cap off and look for bubbles. Do a compression check. Try and pinpoint the problem so you can check for things like a cracked head in a specific cylinder if you find the head gasket to be OK.
Author:  wjajr [ Wed Jul 31, 2024 5:02 am ]
Post subject:  Re: Well, 90% certain my head gasket just went
Once many moons ago after some engine work and a quick reassembly the thermostat got installed bass ackwards, yup spring side out. Once the engine got warmed up the radiator & heater hoses became rock hard from over pressure.

The fix was to remove the stat, re install it and try again, but numb nuts me quickly repeated the same procedure, spring side out... What's the old saying? If one has time to do it twice, why not do it once right? Thank-you Murphy.

Third try I managed to stuff the damn thing into the neck with the spring facing the head, and all was well.

No adult drinks were in use during the above adventure.
Author:  Greg Ondayko [ Wed Jul 31, 2024 2:14 pm ]
Post subject:  Re: Well, 90% certain my head gasket just went
Quote:
Once many moons ago after some engine work and a quick reassembly the thermostat got installed bass ackwards, yup spring side out. Once the engine got warmed up the radiator & heater hoses became rock hard from over pressure.
This seems to be a likely result for the original poster as well.

I cannot understand how blowing a head gasket could make the coolant hoses hard.
Results from a blown head gasket:
- Water or oil in the cylinders/exhaust pipe. yes.
- Coolant in the oil or oil in the coolant? yes.
- Misfires etc... yes and yes..
Author:  mcnoople [ Thu Aug 01, 2024 1:45 pm ]
Post subject:  Re: Well, 90% certain my head gasket just went
Quote:
Quote:
Once many moons ago after some engine work and a quick reassembly the thermostat got installed bass ackwards, yup spring side out. Once the engine got warmed up the radiator & heater hoses became rock hard from over pressure.
This seems to be a likely result for the original poster as well.

I cannot understand how blowing a head gasket could make the coolant hoses hard.
Results from a blown head gasket:
- Water or oil in the cylinders/exhaust pipe. yes.
- Coolant in the oil or oil in the coolant? yes.
- Misfires etc... yes and yes..
Coolant hoses becoming rock hard is also a common symptom of a blown headgasket. Coolant systems operate in the 10-20 psi ranges. Cranking cylinder pressures are above 100 psi. When a head gasket is breached into a coolant passage it can allow coolant to be ingested by the compromised cylinder, but it can also allow the compression/cylinder combustion gases to leak INTO the coolant passages.

If you start a stone cold engine and within 10 seconds of starting the engine the hose has a stiffy its probably not thermal expansion it is probably a blown head gasket.

Of course the hose should only be able to firm up to the limit of the radiator caps rating. A neat trick I found out about a while back is to take an extra long hose and attach it to the radiators overflow. Submerge the end of the hose in water that you can easily observe (cup/bucket). And watch for bubbles, this allows you to keep the radiator cap installed and properly pressurized. Bubbles should only show during system bleeding or very shortly afterwards.
Author:  Dart270 [ Thu Aug 01, 2024 4:07 pm ]
Post subject:  Re: Well, 90% certain my head gasket just went
Cool trick and thanks or the elaboration. I still would look for other signs of a head gasket before pulling the head, and maybe look at the tstat.

Lou
Author:  Charrlie_S [ Thu Aug 01, 2024 4:09 pm ]
Post subject:  Re: Well, 90% certain my head gasket just went
Go to a local parts store, and rent their combustion leak tester
Author:  ScottJ175 [ Wed Aug 07, 2024 11:00 am ]
Post subject:  Re: Well, 90% certain my head gasket just went
Quote:
Go to a local parts store, and rent their combustion leak tester
I happen to own one. Just hadn't taken the time to do it yet. I did today and didn't get a super positive color change in the fluid but while running to do the test I got steam out the tail pipe with that distinctive smell. So once the weather cools off I guess I'm pulling the head if I continue with trying to save this old truck.
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