1989 Accord DX Coolant Leak

I came home today after driving and had coolant in the driveway
originating from the left side front dripping near the oil pan bolt. I
put the car on ramps and tried to find the leak. The leak does not
occur when the car is running, only after you shut it off (which is
common for a water pump). I saw some fluid leaking from the pipe that
goes into the back of the water pump which is sealed with an o-ring.
Has anyone ever seen this seal go? The car has 160,000 miles. It could
be the water pump but it doesn’t look like it is weeping from there but
it is hard to tell. The pipe that comes from the water pump has other
pipes connected to it, but it doesn’t look like they are leaking. It
looks impossible to get at the pipe that comes out of the back of the
water pump. Any suggestions would be appreciated. I plan on taking the
shroud off so that I can get a better look at where the leak is.

 

That's the thermostat-to-water-pump pipe.

Yes. Due to either
1) neglected coolant changes, or
2) rust, or
3) age drying out the O-rings.

#1 and #3 are most common.

Those hoses feed certain engine controls. They don't usually leak. At least
not catastrophically.

Do that. The pipe can be removed once you take off the thermostat housing.

 

The pipe doesn't seem to go to the thermostat housing, it looks like it
connects to the lower radiator hose. How is the o-ring held in, it looks like
the bolt that holds the pipe in place is the only clamp? I looked at an
exploded view on a honda parts site.

 

You are not checking carefully enough. The lower rad hose terminates at the
thermostat housing.

 

that is the thermostat housing. honda have it on the return, not the
feed like most other manufacturers.

it's held in by the thermostat housing being positioned correctly. the
only thing that's sealing it is the o-ring.

 

It does? UPPER rad hose goes directly to the 'stat housing on my 3gee Accord...

 

Check again. Follow the lower hose carefully to its connection at the
engine.

The engine end of the upper hose only looks like a thermostat housing. It's
not.

 

The pipe that goes to the back of the water pump on the carb version of the
1989 Accord DX goes to the lower radiator hose. I verified it on the car and
in the factory service manual. I spoke to a local honda dealer to see if they
have the o-ring, and he said that it common for the pipes to corrode and leak.
Is it common? From what I can see, the pipe looks ok, with a little surface
rust. He suggested that I purchase a new pipe.

 

The thermostat housing is the big aluminum thing between that pipe and the
lower rad hose. It must be removed in order to replace the pipe.

So long as you can find O-rings that are the right size and of a material
that is compatible with antifreeze, you can just replace the O-rings. That
presupposes that the pipe will be in sufficiently good condition to reuse.

My general advice when it comes to cooling system components is not to
skimp. Too much risk to the engine from skimping. I'd be inlcined to get a
whole new pipe, myself.

By the way, make sure the seats in both the water pump and the thermostat
housing are clean and smooth when you perform the service, and lube the new
O-rings with antifreeze prior to installation.

 

I don't need to check it - I've changed the 'stat on this car twice, once when
the one it came with died, and once when the "fail-safe" unit I replaced it with
failed CLOSED (grumble grumble)... trust me, the upper rad hose connects to the
thermostat housing.

The lower hose, BTW, connects to a pipe that runs along the back of the engine
under the intake manifold, and feeds the water pump.

My previous Accord was the same. First one, I couldn't say, because it never in
over 300,000km had a problem with the cooling system.

I'll go take pictures, if you like...

 

There is no "big aluminum thing" on the lower rad hose on the carb'd 3geez. The
hose clamps directly onto the pipe. The thermostat housing is diretly behind
and exactly level with the distributor on these cars.

 

No, I believe you. It's just that the lower hose position is universal
these days, and many people seem to think their thermostat is in the upper
hose when it's not. Guess yours must have been the last of the old style.
And wasn't '89 the last year for a carb in North America?

 

Probably... AFAIK, Honda introduce EFI to the NA Accord with the 3geez (86-89),
so I wouldn't be surprised if carbs were simply phased out through that series.

In any case... there's a tidbit for your FAQ: thermostat housing is at the end
of the UPPER rad hose on carb'd 3gee Accords (and probably carb'd versions
before that as well).

 

Pretty close I think. I know my 89 accord is the last year for carbs
in the accord. Starting 1990, all accords were EFI. They did sell the
EFI version for 86-89, but added the "i" to the name. IE: the accord LX
EFI
version was the LXi. Or I think anyway.. Mine is just a regular LX, so
it's got the 2bbl carb.
MK

 

Getting back to the original problem of the coolant leak, it turned out to be a
pin-hole leak in the metal water pipe that comes from the water pump. It does go
from the water pump to the lower radiator hose. On the 1989, the thermostat is in
the upper radiator hose. I ordered a new part. Thanks for all the help.

 

Yeah, TeGGer, told ya so Nyah!

Just kidding

 

You're a meanie. I'm telling Mom on you.

 

Mom always did like you best. :'(

 

That's because *I* took out the garbage when I was told to, unlike you...

 

Yeah, well *I* wasn't the one who let her buy a f... f.... F*RD.