Your hoses are old and have lived out their useful life. The ends that connect to the heater valve and pipes have corrosion build up that won't let them seal properly. We have found a great alternative to the discontinued OE heater hoses.
This kit includes all 3 hoses and OE wire hose clamps (or upgrade to the bitchin' OE spring clamps shown in the slide show that hold the proper tension without any need for re-tightening).
Some very slight trimming may be necessary depending on your year.
hoses are made in the USA, clamps are OE Toyota from Japan.
Sorry, not available for pre-1984, 86-88' turbo trucks or those of you with a rear heater