horget96

Hello, I have a 1990 Toyota 4x4 v6 with a manual transmission. I seem to have a coolant leak and I believe I have it narrowed down to which hose is leaking.
Problem: I have noticed twice coolant leaking from my the driver side of the car. I got underneath the truck and the lower radiator hose looks fine. It is not bulging or anything. The radiator didn't have any apparent holes. The hose the runs under the oil filter, which I think is a coolant hose, is bulging and seems to be the culprit. My local dealer doesn't have a clue. Does anyone know what that hose is called or a part number?

PismoJoe

Can you see it here?

http://www.utoyot8.com/Picture.aspx?...ccode=&ppName=

If so, then its one of these

http://www.toyotapartszone.com/onlin...onentsIndex=15

This site is great for getting detailed diagrams, just snoop around that site if this isn't one of the hoses that you were talking about

93yotaSR5

i believe its for the stock oil cooler. hose runs from the bottom of the thermostat housing under the oil filter to the right of the filter. its more of a heat exchanger.

horget96

Yeah 93yotaSR5 I believe you got it. I can't tell if it is on the diagram that PismoJoe sent. So it is a coolant line then.....

scope103

The only hose that I know of, that can be found "under" the oil filter, is to the oil cooler. http://www.utoyot8.com/Picture.aspx?...8808-++++)3VZE

Of course, that line is full of oil, not coolant.

Hence the perennial problem finding leaks: gravity is not your friend. Where ever it is actually leaking from, it will end up at the lowest point on the engine. You will need to get that engine clean enough to eat from, and then look for the leak.

Good luck.

PS If that hose is bulging, by all means replace it. Rupturing an oil cooler hose on the road would get unattractive quite quickly.

93yotaSR5

word! i plan on putting an aftermarket cooler on mine. im afraid of it bursting all over the place.(thats what she said)

DancesWithBikers

Actually, both the hoses carry coolant. The long one connects to the water pump, and the short one feeds into the block.

The oil circulates only within cooler cylinder itself, via the large hollow bolt.

I'm quite sure of this, as mine is in pieces right now. It was the source of my nasty oil leak. To be more precise, the loose bolt was. It's supposed to be torqued to 43 ft/lbs, and could be turned with my fingers!

Tomorrow's job is to finish cleaning up the mess, and put the oil cooler back with new seals.

I may have another problem though, there's no flow between the two coolant fittings. Is there a thermostat in there, or should it be flowing freely?

scope103

My mistake. (I don't have that cooler on my '94 SR5; there is a "cap" on the block at that point.)

Coolant actually makes more sense, but losing coolant through a broken hose is only slightly better than losing oil.

sb5walker

Speaking of, replace the seals in that oil cooler when you replace the hose. They are known to deteriorate and allow coolant into the oil. They should be cheap - certainly cheaper than bearings.

DancesWithBikers

They are cheap, all three were about $12 at the local dealer.

On the other hand, the cooler itself lists for $6-700!

DancesWithBikers

Nope, no thermostat in the oil cooler, it was just plugged solid. I tried boiling it, as a thermometer test, but it made no difference.

Then I tried compressed air: first from the engine block fitting, figuring that would be against the normal flow. Nothing happened at all, so I tried it from the water pump fitting.

There was a small boom, and something embedded itself in the rafters. There was also a small cloud of mist raining down.

After that, it flowed quite well!