Volvo RWD 700 Forum

INDEX FOR 10/2025(CURRENT) INDEX FOR 11/2011 700 INDEX

[<<]  [>>]


THREADED THREADED EXPANDED FLAT PRINT ALL
MESSAGES IN THIS THREAD




  REPLY TO THIS MESSAGE    PRINT   SAVE 

Gone through 2 top O-ring mushroom seals on water pump in 12 months... 700 1990

I am ready to change water pump seals and gaskets again on Monday (when I can get the parts). Pump is only 4 months old so I will reuse it. Since the top mushroom seal keeps failing I want to try reassembling it the right way this time. I never used silicone grease or red RTV on the previous install. I know that a cam seal leak can help deteriorate the upper water pump O-ring. If I did have a slight oil leak, is there any way I can protect the new seal from contact with oil to keep it from failing so quickly? That is why I am asking about using silicone grease. Maybe that will put a coating on the seal to keep it protected. I don't know, that is why I wanted to check with you. Thanks!
Keith
--
1990 740GL Wagon 228k AW70L B230F 8 Valve Non-Turbo Rex/Regina








  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    Gone through 2 top O-ring mushroom seals on water pump in 12 months... 700 1990

    Thank you rcsammy, brownboy, porkface, mapleleafer, and art benstein for your helpful advice and for art's digital photo. I feel the culprit is probably a sharp edge on the sealing head. I plan to attack it with wet emery cloth first, add a touch of silicone grease, then do rcsammy's trick with the strip of plastic or 35mm negative to protect the mushroom o-ring from getting cut when I slide the water pump into place. This seal problem has been a bother to me since I have replaced all of the heating components: radiator, hoses, expansion tank, expansion tank hose, heater valve, heater valve hoses. I said to myself: "There, I'll never have a problem with the car overheating again!" (Isn't that life?)> But I am not giving up. With the problem comes the challenge, after the challenge is met comes the satisfaction.
    Keith
    --
    1990 740GL Wagon 228k AW70L B230F 8 Valve Non-Turbo Rex/Regina








  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    Gone through 2 top O-ring mushroom seals on water pump in 12 months... 700 1990

    Both seals that have failed have been cut. I think your replies dealing with a pitted or sharp head probably have something to do with the answer. How do you recommend smoothing the head surface so it won't cut the next mushroom seal? I was thinking of using fine grit sandpaper. Got any other better ideas? Yes, both seals were Volvo.
    --
    1990 740GL Wagon 228k AW70L B230F 8 Valve Non-Turbo Rex/Regina








    •   REPLY TO THIS MESSAGE    PRINT   SAVE 

      Gone through 2 top O-ring mushroom seals on water pump in 12 months... 700 1990

      After you get sealing surface of head cleaned up and are ready to install pump, cut yourself a sttip of plastic as wide as the seal and about 3" long from a soda bottle and place between seal and head as you slide it back on the studs. Remove before you lever the pump upwards. This covers the sharp edge of the hole and allows the seal to slip past the opening. I have also used old photographic negatives (35mm) for this purpose. Good luck,rcs.








    •   REPLY TO THIS MESSAGE    PRINT   SAVE 

      Gone through 2 top O-ring mushroom seals on water pump in 12 months... 700 1990

      I used a couple of grits of wet emery paper to smooth out the sealing surface when I did the 240. I also put a little silicone grease on the seal when I replaced it. The auto mechanics instructor who taught me to do it (former Volvo dealer mechanic) used grease on this seal as well as using a little to hold the gasket in place while mounting the pump.

      Hope this helps. What a pain to have to keep replacing the water pump!

      Mike Brown
      Greenville, NC
      1996 965 105K
      1986 244 137K
      --
      Mike Brown Greenville, NC 1996 965 94K 1986 244 137K








  •   REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

    Gone through 2 top O-ring mushroom seals on water pump in 12 months... 700 1990

    the aftermarket seals are notoriously weak. always replace them with volvo seals. a little grease is ok, no sealers. if oil is doing it, then replace the cam seal and/or clean the flame trap. good luck, chuck.








  •   REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

    Gone through 2 top O-ring mushroom seals on water pump in 12 months... 700 1990

    It's more likely that you are cutting the seal during installation. Even oily, those seals stand up much longer than a year. Be sure the underside of the head is fairly flat and clean. You should not need grease, and RTV is made for use in place of gaskets - not in addition to.








  •   REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

    Gone through 2 top O-ring mushroom seals on water pump in 12 months... 700 1990

    Is it mushy and bloated? That'd be the oil problem. Don't know any way to protect it other than renewing the cam seal or maybe even valve cover at that point.

    But it could be failing to do its job even in good shape if the sealing surface of the head is pitted. It's hard to see this without strong light and mirror, but worth close attention during the coolant pump changeout.


    --
    Art Benstein near Baltimore







<< < > >>



©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.