[Art]

Very common on the Liberty’s, I did two of them. You have to pull the water tank which is no a big deal to get the heater out.

[John]

It is likely the tank expanded because two things happened during its life. First, the temperature/pressure relief valve started dripping and someone who did not realize the one on the tank has to be a 75 PSI valve replaced it with a valve available at Lowe’s or Home Depot that was the common 175 PSI valve used in home HW tanks.

That alone did not cause the tank to expand. But Liberty coaches have an expansion tank in the water system and a check valve in the water supply line to the HW tank. If the expansion tank bladder failed due to age and the tank was no longer functioning (the water pump would short cycle) as the tank water expanded when being heated especially by engine coolant the expansion was not absorbed by the expansion or accumulator tank and the resulting build up of pressure made the tank top and bottom expand. That expansion could have also been caused by the in line check valve which should have a minute hole to restrict water flow, but not prevent it. The check valve protects against a back flow of scalding water in the event of a pipe failure, but it does need to allow expanding water in the tank to distribute the increased pressure to the expansion tank.

If the tank has expanded so much that it is wedged between the top and bottom of the bay it may need to be cut out of place, a nasty job.

Liberty owners need to pay attention to this feature of their plumbing system and above all else never replace a 75 PSI valve with a 175 PSI valve.

[pierre]

I was able to get it replaced today. A bigger job then I was thinking, but not too bad. The bottom of the tank had expanded, which was causing the top to push into the engine coolant lines. They had made about a 1.5 inch indent in the top of the tank from the pressure.