1. Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!
  2. ALL NEW MEMBERS READ THIS FIRST!! Thank you for joining Heavy Equipment Forums! If you are new to forums we communicate with "Threads", please search our threads to see if your topic may have already been answered and if not then click "Post New Thread" in the appropriate forum. This will allow all of our members to see your question and give you the best chance to be answered. After you've made a number of posts you will graduate to Full Member status where you'll see a few more privileges. Following these guidelines will help make this the best resource for heavy equipment on the net. Thanks for joining us and I hope you enjoy your stay!!

Cummins 5.9 oil leak from new vacuum pump gasket??

Discussion in 'General Industry Questions' started by Camshawn, Aug 10, 2020.

  1. Camshawn

    Camshawn Well-Known Member

    Joined:
    Jan 25, 2017
    Messages:
    156
    Location:
    Langley BC
    In my pickup, replaced the power steering pump and Vacuum pump due to an oil drip from the seal between the two. New gasket on cleaned surfaces between the gear case and the vacuum pump, bolts tight and I am getting an leak from the flange through the gasket on the bottom side. Any advise? Silicone or form a gasket between the gasket and the flanges? The bolts are tight.
    Cam
     
  2. Truck Shop

    Truck Shop Senior Member

    Joined:
    Dec 8, 2015
    Messages:
    7,904
    Occupation:
    star gazer
    Location:
    SE Washington St
    The only sealer I would use is NAPA The Right Stuff and a thin amount at that. Or you could use Indian Head and never take it apart again.
     
    Camshawn likes this.
  3. MarshallPowerGen

    MarshallPowerGen Senior Member

    Joined:
    Nov 27, 2017
    Messages:
    275
    Occupation:
    Generator & Equipment Mechanic
    Location:
    Coeur d'Alene, Idaho
    We use Right Stuff at work, but my old employer spoiled me with Yamabond. Better flex and better seal than anything else I've used (still use it for all my personal stuff).
     
    Camshawn and funwithfuel like this.
  4. Birken Vogt

    Birken Vogt Charter Member

    Joined:
    Nov 30, 2003
    Messages:
    3,740
    Location:
    Grass Valley, Ca
    I like high tack for paper gaskets but the variety of sealers seems infinite and I have not tried each one yet.
     
    Camshawn likes this.
  5. Camshawn

    Camshawn Well-Known Member

    Joined:
    Jan 25, 2017
    Messages:
    156
    Location:
    Langley BC
    Thank you all for your replies. I will pull the vacuum pump again this morning to make sure there is not a piece of crap on the face or a fold in the gasket that I missed, then off to Napa to get some sealer. Nothing fresh here at home. I will try to get one of the ones recommended above. Cam
     
  6. Engineer44

    Engineer44 Well-Known Member

    Joined:
    Nov 30, 2017
    Messages:
    47
    Location:
    Portland
    Permatex Ultra Black Maximum Oil Resistance is the best stuff I’ve used. Just be sure the parts to be joined are perfectly clean/oil free. I wipe the surfaces with Brrakleen until the cloth shows no discoloring. I’ve sealed some difficult to seal joints years ago and they are still bone dry.
     
    Camshawn likes this.
  7. Ben Witter

    Ben Witter Senior Member

    Joined:
    Apr 3, 2013
    Messages:
    252
    Location:
    On the outside
    What year Dodge? If you thoroughly cleaned both surfaces and there were no defects you should not need any sealer. Did you replace them with new or used parts? If you cleaned them did you use a powered surface prep disc and possibly remove too much material from the timing case? The seal on the vacuum pump is easily replaced with a $20-30 kit
     
    Camshawn likes this.
  8. Camshawn

    Camshawn Well-Known Member

    Joined:
    Jan 25, 2017
    Messages:
    156
    Location:
    Langley BC
    Truck is a 96 with 260,000 km. The gasket kit for the pump is $110 can$. The aluminum case and insert need to separate to replace the seal. An hour tapping, pressing ect and the 2 would not come apart so a new pump was purchased for $600. There is also some scoring inside the “chamber” from the vanes, probably not enough to cause a problem but....260k. With the cost of a new computer controlled truck and the places we go, I would like to keep this one another 10 years. The only rust is at the bottom of the passenger side fender. I am just going out now to pull it apart again and see if I can spot the root cause of the oil leak. Cam
     
    Truck Shop likes this.
  9. Ben Witter

    Ben Witter Senior Member

    Joined:
    Apr 3, 2013
    Messages:
    252
    Location:
    On the outside
    https://www.ebay.ca/itm/Vacuum-Pump...687835?hash=item4d9913b6db:g:ZqoAAOSwyNtdPwOq
    https://www.ebay.ca/itm/Cummins-Gen...462896?hash=item23d111d7f0:g:nqUAAOSwKsdbYytF

    Seal kits are cheap. The seal retainer just needs some persuasion with a decent sized hammer. But you have already gone down the road you have chosen.

    If it is leaking there is either debris left on the surface or the surface is not true. If you are going to use RTV or gasket maker I would just toss the gasket and use the sealant alone.
     
    Camshawn likes this.
  10. Camshawn

    Camshawn Well-Known Member

    Joined:
    Jan 25, 2017
    Messages:
    156
    Location:
    Langley BC
    Thanks for the links. I never think of buying parts on line. I found a little thread damage on the new gasket from the bottom bolt. I reinstalled the old gasket(also 10 thousands thicker) and the leak is gone. The only good thing was none of the bolts had any corrosion on the threads. I pulled the pump combination back enough to slip out the gasket, wipe everything clean and get the old gasket back in with the hoses still attached.
    Thanks for all the tips. Cam
     
    Theweldor and Truck Shop like this.