overheating on 1988 toyota pickup, blown head gasket, head

I have a 1988 toyota pickup 2.4 liter 4 x 4.  The radiator was plugged and cause the unit to heat up running down the road.  Replaced radiator, all new hoses and thermostat.  Filled with coolant and started unit.  Found that the truck heated up and pushed coolant into the reservoir.  It will not pull the coolant back into the system as it cools down.  Replaced the hose and lid to the reservoir.  Filled system and the coolant ended up in the reservoir and did not get pulled back into the system as it cools.  System holds pressure until the cap is removed.  Has new cap, with 13 PSI.  Don't no why the system cools down and will not pull out of the overflow tank.

Answer
    You have a blown head gasket.  When 4 cyl. Toyotas overheat, they always blow their head gaskets.  But the problem is even worse, because the overheating almost certainly warped the bottom surface of the head.  This is why the gasket fails, it no longer has a flat surface to seal against.  You may be able to have the head resurfaced, depending on how bad the warping is.  If it is really bad you will have to buy a new head.  Fortunately the actual job of removing and replacing the head is not a big deal.  I would advise replacing the timing chain at the same time, unless it has already been replaced in the past.  The only special tool needed is a torque wrench.
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