backside of waterpump tube

[notnilc20]

what is the deal with this tube? it connects the inlet and outlet....but why? also it's not very tight....it just pulls right out.

[jdm86gtz]

That is the thermostat bypass pipe and you need 2 new o-rings on it.

[davew7]

You need the tube to circulate the coolant before the thermostat fully opens. There should be an O-ring on both ends of the tube. Replace the O-rings and then coat both ends with RTV just before installing the head. Dave W

[notnilc20]

ok thanks guys.....i hope it will seal good enough to withstand the pressures of the water system.....

[MisterJerk]

these are still available new from toyota. the pipe with o rings

[Deuce Cam]

You need the tube to circulate the coolant before the thermostat fully opens. There should be an O-ring on both ends of the tube. Replace the O-rings and then coat both ends with RTV just before installing the head. Dave W

If the tube and female receivers are cleaned up shouldn't the O rings be enough?

[davew7]

I honestly do not know! The first 4AGE that I rebuilt about 13 yrs ago showed signs of leaking at the o-ring. Who knows how old the O-rings where. Cheap insurance to add a little RTV to the joint [plus O-rings]. I've incorporated the RTV in the last 3 rebuilds. The way I look at it, It's easier to take 2 minutes to seal the joint, Vs pulling the front of the engine to fix a leak after the fact. Dave W