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spankyjr1, Journeyman
Category: Medium and Heavy Trucks
Satisfied Customers: 2621
Experience:  I worked on all types of equipment semis,forklifts,farm,ect.
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We replaced the pins on a 1990 mack rb688s. when we greased

Customer Question

we replaced the king pins on a 1990 mack rb688s. when we greased the pin the top cover pops off. what are we doing wrong?
Submitted: 2 years ago.
Category: Medium and Heavy Trucks
Expert:  spankyjr1 replied 2 years ago.
Hi, my name is ***** ***** you for your question.
Your not doing anything wrong, this sometimes happens when king pins fit tight,,the grease acts like a hydraulic jack and the grease can't get by pins inside bushings so the cap pops off since that is the path of least resistance.
Try jacking up the wheel,,use big C clamp or other device to wrap around entire king pin and spindle all the way around so it holds top and bottom together,,a smaller tie down strap will also work..then grease it.
After you get it to take grease without popping it off a few short trips will prevent this from happening next time you grease it,, its just too tight right now,, I have ran into this several times in the past.
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