Water pump leaking at upper gasket

[saq]

This is the second Volvo I've had this happen to - a leak develops at the seal between the water pump and the cylinder head. The first time this happened it was just a trickle, so I could keep on driving the car until a new pump and gasket arrived, but this time it's leaking far too much to drive.

I went through the maintenance documentation and can't see when the pump was last replaced (I have docs for the past 50k or so miles, but I can call the mechanic to check before that to see if the P.P.O. had it done I suppose), so I'm wondering about replacing the pump vs. getting a new set of gaskets and O-rings. That's what I wound up doing last time, but the pump was probably OK and good for another 40k or so.

I'm trying to decide (a) if the water pump should go ahead and be replaced (it's a 1986 740 non-turbo). The problem with replacing it is that I seem to either have a choice of the GMB from IPD, which will come pretty close to the day after I order it, or waiting with the car out of commission for a week for a Hepu to come from FCP Groton, because it doesn't look like there are any PNW sellers of repute who have the Hepu pumps (grr).

Also - the two cars that I have had this happen to appear to have been sealed by squirting RTV silicone between the pump and the head. Is this common now? Was there an additional seal that just deteriorated? I know the mechanic that replaced at least one of them, and he's definitely not a fly-by-night quick-buck operation. I haven't pulled the pump on the 740 yet, but I see the black RTV. The 240 I know didn't seem to have any O-ring in place.

[Ryan_R]

If you get a Hepu pump, get a top seal from the dealership.

The ones supplied with the Hepu pump are junk. I had two fail within a year. Never had a genuine one fail.

The pumps themselves are supposedly quite good.

-Ryan

[nel621]

Try RM European for the parts.May arrive faster.

[Lando]

I get most FCP parts within a day of being shipped.

[BlueSwede]

RTV is fine but make sure it is coolant/high temp safe and there should be two Orings on the pump, one on heater core line and one on engine block/head...

[Mr. V]

Make certain you pry up on the waterpump to compress the upper rubber seal and keep compressing it while you tighten the bolts.

Otherwise, it'll leak.

[saq]

Originally Posted by Mr. V

Make certain you pry up on the waterpump to compress the upper rubber seal and keep compressing it while you tighten the bolts.

Otherwise, it'll leak.

I wonder if these were both done right when Hepu switched over to the cheapo seals, because they both started leaking at the top.

I'm wondering about loosening the screws and re-compressing the top to see if the leak can be slowed until the parts get here. Went ahead and ordered the Hepu from the East, not holding out any hopes of a rapid arrival.

Is the back gasket from Hepu OK, or should I get a replacement for that as well?

[TrickMick]

http://www.volvopartswebstore.com/pr...5/1336255.html

I've used the HEPU pump *KITS* for over ten years now and NEVER had a problem
w/the seals / gaskets / O-Rings
GLUE the gasket to the pump body using 3M "gorilla snot" and then smear the "mating face"
w/the Volvo "pink goo BRAKE PASTE" (it's a SILICONE paste)..the HEATER pipe gets a GOOD
SCRUB w/a BRASS BRUSH and I make SURE it's *round* by swiveling a punch inside the bore...
you put the "flat O-Ring on the PIPE and hit it w/a smear of the pink goo...
the TOP HAT "O-Ring gets a small smear of the brake goo and thence to the install phase...
the BIG DEAL is to get the PIVOT bolt in first and then prise the pump UPWARD to mate w/the
head - hold there and snug the rest of the bolts as you install them...

SURFACE PREP (as in painting) IS *EVERYTHING*...clean / dry / artifact free surfaces
(scrape w/single edge razoo blade held 2 90* to the surface)...CLEAN and NICK FREE...

good prep / good install = NO WORRIES!

[Lando]

Originally Posted by TrickMick

http://www.volvopartswebstore.com/pr...5/1336255.html

I've used the HEPU pump *KITS* for over ten years now and NEVER had a problem
w/the seals / gaskets / O-Rings
GLUE the gasket to the pump body using 3M "gorilla snot" and then smear the "mating face"
w/the Volvo "pink goo BRAKE PASTE" (it's a SILICONE paste)..the HEATER pipe gets a GOOD
SCRUB w/a BRASS BRUSH and I make SURE it's *round* by swiveling a punch inside the bore...
you put the "flat O-Ring on the PIPE and hit it w/a smear of the pink goo...
the TOP HAT "O-Ring gets a small smear of the brake goo and thence to the install phase...
the BIG DEAL is to get the PIVOT bolt in first and then prise the pump UPWARD to mate w/the
head - hold there and snug the rest of the bolts as you install them...

SURFACE PREP (as in painting) IS *EVERYTHING*...clean / dry / artifact free surfaces
(scrape w/single edge razoo blade held 2 90* to the surface)...CLEAN and NICK FREE...

good prep / good install = NO WORRIES!

I'll have to try the brake goo the next time I do a water pump on these blocks. You certainly know what your talking about, and I havent always had the best luck with top hat seal.