In Reply to: 8n hydraulic problem posted by Mitchell on May 25, 2020 at 14:20:25:
You have a severely worn hydraulic system and it's time for a rebuild. Simply draining the old oil and replacing with new oil isn't going to fix anything. You describe signs that the cylinder is worn amongst other issues. We have our HOW-TO's forum (note rd menu bar at top of home page) with many DIY and self-help projects. One is listed below -click on the LINK. If you've never pulled the top cover, it would be wise to get the Essential Manuals and the documents and read first. The cylinder is bolted to the underside of the top cover with four bolts under the seat area. If you remove them BEFORE you pull the top cover you will do extensive damage to the unit and have a massive project getting it off then. The hydraulic system repair isn't that big of a job, but is very time consuming. Best to have a helper too. The OEM N-Series hydraulic cylinder used a 3-steel ring piston. This was replaced with the NAA-530-A piston with a rubber O-Ring. It is a better design and will also work on the 9N,2N, and 8N as well. You will need a new cylinder (don't try to reuse old one); a new piston; a gasket kit; a new safety relief valve; and possibly some pump parts. Don't buy anything til you get the pump off and on your bench. You are going to want to inspect the aluminum pump base and if cracked will need to replace it. New parts can be found at trusty sites like Dennis Carpenter and Just8ns. READ all the manuals first.
FORD 8N TRACTOR ESSENTIAL OWNER/OPERATOR/PARTS/SERVICE MANUALS: