A borated bis succinimide, containing a high level of boron (preferably 1.0 to 3.0 wt. percent) is prepared by heat reacting a corresponding bis succinimide in mineral oil solution with boric acid and water at an elevated temperature of at least about 177.degree. C. Superborated succinimides prepared in the foregoing manner are useful as borating agents for ashless nitrogen containing dispersants. Lubricating compositions which incorporate nitrogenous ashless dispersants borated with the superborated succinimide of the present invention show reduced tendency to degrade engine seals manufactured from fluorine containing elastomers.