'73 merc 1150 power trim leak control valve

I have a '73 merc 115 hp 6 cylinder with the external power trim motor. The problem I am having is that it leaks in between the control valve and the plate between the reservoir. I took it apart to find a bad o ring. I went to the parts store and was not able to find any o rings similar, does anyone know where I can find these or aany suggestions would be great. Thanks for looking

For a little backround I just bought this boat for a great deal and am in the process of restoration. The previous owner cut out the rotten floor and then lost interest. The motor runs great but I am having the issue with the power trim. This is my first restoration of this caliber but is going quite well thanks to iboats forums, I already have replaced the stringers and have the plywood down and am in the process of glassing the floor. Carpet comes in on Monday new seats on Tuesday, my hold up is going to be the power trim. I went to the local auto parts store and got some o rings but they were too thick and didn't seat in the grooves, they worked for awhile but then blew out again. The only answers I get from marinas is I need a whole new pump, which really sucks considering the pump works excellent it just leaks fluid due to bad o rings. This motor has 7 o rings and the problem ones are the two that are oblonged in shape, if anyone can help I would greatly appreciate.

Re: '73 merc 1150 power trim leak control valve

Might anyone have parts #'s to these o rings so I can search for them that way, I was told they used to sell them as a set but no longer do

Re: '73 merc 1150 power trim leak control valve

Crowleymarine shows part number 48171 as the oring you need (.90 ea)

I looked up my '77 Merc 1500, serial num 456****. However, these should be common to all the trim pumps

BTW - I never thought those orings were anything special. Mine never leaked in 25 years.

Re: '73 merc 1150 power trim leak control valve

Thank you for your reply, those are not the o rings I need it's the ones on the other side of that plate in the control valve, but I found them in the other diagram with the controls and they are ordered!! You are right those ones are no big deal it's the other ones I need that are oblonged and sit in a seat. But crowley marine has them and they are on their way Thank You so much for your help, and now I have a place to get parts!