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Dino Saga 051030 _ Water pump repair

Discussion in 'Corbani's Corner' started by John Corbani, Oct 30, 2005.

  1. John Corbani

    John Corbani Formula 3
    Honorary Owner

    May 5, 2005
    1,153
    Santa Barbara, CA
    Full Name:
    John Corbani
    #1 John Corbani, Oct 30, 2005
    Last edited by a moderator: Sep 7, 2017
    Dino Saga 051030 _ Water pump repair

    Water pumps go. About every 30,000 miles, 5 years of driving, sorta like tires. First time my shop fixed it and I got the standard sticker shock. Fixed it myself after that. Learned a lot and now it is a trivial problem. I save all the dead pieces. Some are the models for this post’s pics.

    The two failure points are water seal and bearing. Seal is easy. Bearing is a little harder. First thing is to get the pump loose. If in the car, it can be removed by first removing the oil filter and water pump pulley. You need small hands but you can get all nuts, bolts and hoses loose. Make sure that ALL are out and you have all the washers. Once the pump is out, the seal can be changed without taking off the pulley hub. Just remove impeller, yank out old seal, press in new one, clean up impeller seal surface, press impeller back on and you are done. Removing the impeller is the trick. I found that a drain plug, some washers and a couple of steel nuts make it easy. There is probably a Ferrari tool but…$$$

    The first pump failure I tried to fix was a bad bearing. You can see how bad. Bearing/shaft assembly is one piece and is a slip fit in the housing. A dog point screw makes sure the bearing OD does not move. Remove the pulley hub, impeller and dog screw. Bearing might slip out. If not, support the housing and press the bearing assembly out. A little heat from a propane torch might help. Go easy. Housing is fragile.

    I had no info on removing impeller. Back end cavity was full of corrosion. I cleaned a ½” hole, supported the impeller on parallels and pushed on shaft. Outside edge of impeller cracked. Had nothing to lose now so broke more of the blades off. Then drilled through impeller and cracked hub. Found threads under the corrosion. Damn. Went down to my NAPA store and asked about big metric bolts. No have. But sales lady said “I have a steel oil drain plug with M18-1.5 thread”. Smart lady, quick sale. GT Car Parts had a new impeller, seal and shaft. Next day I slid bearing into housing, installed screw with Locktite, pressed on pulley hub, pressed in seal with a little red silicone. Pressed on impeller until there was about 0.020” clearance below edge of housing. Lasted about 4 years. Seal spring broke. Weird. Green water sprayed. Attacked clear coat. Damn.

    Now I was ready. Removed pump, cleaned out impeller corrosion, got out drain plug, some washers, 3/8" nuts and some grease. Held pulley hub in vise, Ran in plug until it bottomed. Marked plug and ran it back out. Put grease and enough washers into back of impeller so that I had 1 turn of push on the shaft before plug bottomed. Ran plug in and shaft moved. You want to make sure that there is at least ¼” of threads pushing. When plug bottoms, pull it, add washers or nuts and repeat. You want to only go about 1/8” at a time. Once impeller is off, pull seal, use a little red silicone on new seal and press everything back together. I put a thin film of red silicone on both sides of the gasket and have never had leaks. Make sure washers go back right side up.

    One of these days I will drill and tap the plug to something like M10. Then I can screw the plug all the way into the impeller, run a long hard bolt through the plug and push the impeller off in one step.

    Wish all things were that easy. They usually are, the second time.

    John
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  3. pma1010

    pma1010 F1 Rookie

    Jul 21, 2002
    2,559
    Chicago
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    Philip
    John:
    I love reading your posts. Makes me want to buy a Dino!
    Thanks for sharing
    Philip
     
  4. synchro

    synchro F1 Veteran

    Feb 14, 2005
    9,263
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    Scott
    Bump for OMGJon's restoration convenience.


    PS - over 12 years ago I bought a brand new water pump assembly with housing and also an additional full rebuild kit. Although I anticipated a failure, it hasn't happened (I carry the full housing on the road for long trips so I could just R/R it in a pinch).
    If you want, I can get the bearing number from the parts packages.

    Scott
     
  5. synchro

    synchro F1 Veteran

    Feb 14, 2005
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    Scott
    #4 synchro, Oct 5, 2008
    Last edited by a moderator: Sep 7, 2017
    That OEM pump of mine was loaned to Jacques and he has manufactured a limited run of water pumps for the Dino. Improved seal and larger bearing were designed. I believe the first two will be sold quite cheaply as he wants some in the field.
    Currently on eBay with a No reserve price:
    http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=190255917276

    Seems like a steal as Rutlands is selling their repro H2O pump for $875 and only one of the two gaskets needed
    http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=200044792849



    PS - added photos of The MaseratiSource water pump that Jacques has produced.
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