1989 Toyota 4Runner Leak

FLYGARN

MEMBER
1989 TOYOTA 4RUNNER

Engine Cooling problem
1989 Toyota 4Runner 6 cyl Four Wheel Drive Manual

Hi,

I have a rather big leak from my engine cooling system and it looks like the water comes from a little hole on the water pump housing next to the thermostat.
I wonder if this is an indication of water pump failure or could it be something else.
And why is there a little drain hole from the water pump housing?

I very glad if you have an answer to my question.

Sincerely

Peter

1 Reply

MHPAUTOS

MECHANIC
31,938 POSTS

Hi there, if the leak is from the drain hole the seal's leaking and the pump should be replaced, if not pressure test the system to help locate the leak.

Just a wee bit of techno info on water pump design, happy reading.

Mark (mhpautos)

A water pump is capable of avoiding adverse influence of water leakage from a swirl chamber to a bearing. The water pump includes a pump housing, a rotary shaft supported by a bearing mounted on a boss portion of the pump housing, an impeller fixed on an end portion of the rotary shaft extending into a swirl chamber defined within the pump housing, and a mechanical seal disposed between the impeller and the bearing. The water pump further includes a seal ring disposed within a space defined between the mechanical seal and the bearing for dividing the space into a first and second vapor chambers with drain holes provided for respective first and second vapor chambers.