If leak is at hydraulic head end cap it may be possible to fix on engine. If head to housing seal leaks it must be torn down after removal from engine. Just resealed one for a 135 and mailed back to Missouri. Have found is usually better in long run to replace all gaskets and seals, patch jobs start leaking somewhere else soon after. Pump is not hard to remove/replace, is simple to time also. Be glad to explain if you like call 574 893 4172 after 7 PM Eastern time, can talk faster than type.