Leaking coolant from crank seal on 1991 toyota sr5 4x4 pick up. i figure the water pump has a seal gone behind timing cover and no other leaks it over heated today at highway speed .

Fit a new water pump ,the seal is leaking and stops when it warms up.

sorry water pump seal ,change it before it packs up completely

This does sound like your water pump is leaking, or your head gasket has busted on the outside edge. I would check the water pump first, as it is fairly common for the seal to bust and leak coolant from the water pump.

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The timing cover itself does not seal any oil from leaking. It is just a cover to prevent debris from getting into the timing belt and ruining it.

To find the oil leak you will need to remove the timing cover and inspect the seals behind the cam gear, crank gear, and oil pump drive gear, and the oil pump to block seal. The most common leaks on these are the cam gear.

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Check to see if the intake is leaking out of the corner and leaking down behind the water pump. If not the timing cover could be leaking. The timing cover gasket also seals the water port that goes to the water pump.

it's sounds like the water pump it only leaks when it's cold because when the engine is hot the seal in the water pump swells up to seal the leak then as the temperature cools off the seal goes back to normal and allows coolant to go by

Could be water pump weephole leak or water pump gasket under water pump trailing down timing cover and exiting behind crank pulley or water . Worse case, leak in timing cover. Water crosses through timing cover to and from water pump to engine block.

Water pump is on the left side of the timing belt in the cover and spins on an O-ring to adjust the belt. Their is a coolant pipe to the the thermostat housing behind the timing covers backing plate also. Be sure to replace the timing belt with the tensioner/ oil seals along with the water pump. Remove the timing covers back plate and you will find two bolt to the pipe as mentioned. It has a large o-ring behind it. Have fun with this one. From: Ronnie Wrench

On a 22RE the oil pump is on the timing cover behind the crank pulley/harmonic balancer,it has the crank timing pointer built onto it,generally they don't leak around the pump seal but as Monster80 pointed out they leak from the front main seal wich is installed on the front of the oil pump,pretty common for the 22R/RE to leak around the timing cover gaskets or out the bolt holes on the timing cover also,usually due to uneven tourqe on the bolts,to check the front main seal you need to look at the the crank from the underside right after you've shut the motor down,if the seals bad you'll see oil starting to form a drop on the backside of the pulley or the front of the oil pump housing.

your water pump is leaking and most likely you had a small oil leak under there also and now the coolant is washing it out, don't go too long with these leaks because your timing belt is under there and is getting soaked with oil and and coolant this will break or slip off causing major engine damage to result (i.e bent valves) good luck and please rate -jeff