Over pressure cooling system

[Cody.Loyd]

Need help, just bought an 87 xr4ti and ran fine for a week and then one day I shut the engine off and noticed steam and popped the hood and saw a coolant leak from a hose to the water pump. I replaced the hose and drove the car again and when I turned the engine off the same thing happened except now it burst the hose going to the radiator. Seems like the cooling system is over pressurized. I don’t notice any coolant in the engine oil so I don’t think it has a blown head gasket. Has anyone else had this issue? Bad radiator cap? Thermostat? Water pump?

[thesameguy]

The reservoir cap is the pressure relief, so if you don't have a history on that it's a good place to start. Even if you have a blown head gasket, the cap should release pressure to the outside world, not wait for hoses to blow. I'm not saying you don't have a bad head gasket, but even if you did that would be odd behavior. It could also just be you have old crappy hoses - they don't last forever... most manufacturers recommend replacing rubber hoses every 5-7 years. Similarly, you could have an obstruction in the radiator - damage or sediment. If pressure can't be relieved on the other side, it will definitely build up between pump and radiator.

[eaton53]

I just got an obstruction cleared out of my rad.
I don't know far the OP got before there was steam, but mine didn't get very far at all. It got hot real fast.

Fortunately I had just gotten the car out of storage so I was right by my house.
I never go far at first, just keep driving it around the block until I see that everything's ok. This time it wasn't!

In my case, the solution was to get the thing power flushed within an inch of its life.
Did it multiple times until we were sure there wasn't a speck of grit in it.
The good news... didn't have to replace a single part.

[Mike McCreight]

Try a cap for sure, but be prepared.
I had the same issue on the eve of Carlisle back ~ 2000 or so.
First one hose went, then another, then...
I wound up driving all day with the cap loose, which worked out fine, until I stopped...
Which was fun, on an 8+ hour trip.
Turns out all of my hoses were due for replacement.
I wound up with ALL silicone after that. It took some ingenuity, but it's done.

[Cody.Loyd]

I think I will start with checking the cap. I don’t think it is the hoses because the second time it happened I immediately popped the hood and noticed the steam building up like there was too much pressure and almost as if it found a weak spot and started spraying coolant out of the radiator hose. Seems like an over pressure issue. It also only builds up too much pressure after the engine turned off.

[Cody.Loyd]

Did a pressure test on the cap and seems to be letting pressure out over 16psi. I guess next I’ll try and flush the radiator see if there is any obstruction.