1948 Ford 8n pto oil kind?

[Sal69]

I have a old pto 8n ford. I'm pretty sure its a 48 but could be a 46 or 50. I'm not too sure on that.

I have the problem of when the oil gets warm it doesnt want too pick stuff up, oh when its cold it'll pick up 800 pound hay bails but when its hot it needs help.

I know it may need a new pump but I've been told if I change the oil it may help. The oil looks brand new and is clear, but has been in it since at least 04. I need to know what brand is a good brand and what just do I need. I'm at a lost because this is my first tractor and I've never had a PTO before.
Thanks for any help in advance.

 

[Food Scientist]

I would check the seals on the inside of the cylinder. I would think that as the oil gets hot, it can get by the seals easier, which would cause your non-ability to pick stuff up.

 

[Sal69]

Thats what I heard but the guy telling me this was trying too sell me a new rebuilt one for 300 bucks, where another guy will rebuild my current one for $80. But the second guy also said it may help by changing the oil in it.

 

[George Bynum]

Originally Posted By: Sal69
I have the problem of when the oil gets warm it doesn't want too pick stuff up, oh when its cold it'll pick up 800 pound hay bails but when its hot it needs help.
The seals comment is good, but IME, well over 90% of the time it is the pump which is worn when hot oil reduces performance. If you can get a flow meter in the pressure line, see if flow is maintained when the oil gets warm.

There are disadvantages, but a heavier oil or one with a higher viscosity index will help a little. Be wary of cold weather, and try an ISO 68 grade.

 

[Steve S]

check the hyd pressure first.

 

[51Plymouth]

As far as the pto oil kind, I wouldn't use hydraulic fluid. The hydraulic oil is also shared with the transmission and differential. If you want to read a good article about it, check this out - www.ytmag.com/articles/artint251.htm

Basically it says you can either use an older spec. of gear oil, or universal tractor fluid which is thinner. My tractor is a similar but older 1942 Ford 2N and has unknown fluid in, from when I bought it a couple years ago. It smells a bit like gear oil, but also smells a bit like and is a bit thin like modern tractor hydraulic fluid.

 

[Sal69]

Thanks for the oil type, I have the trouble shooting the pto lift list from the same site. I guess I didnt think to look there or over looked it.

Thanks again everyone for the help.

 

[philipsearcy]

You are talking about equipment that is over 60 years old! Who knows how it was maintained in the past? There is no filter in the system, and if water ever got in, I have seen the cylinders freeze and crack. It is more than likely time for a mechanical rebuild. YTMag is a great resource. There is also a video you can buy that takes you step by step on the rebuild process. Check your system pressure. Take the side cover off and look for leaks. Pull the pto, drop the pump, and remove top cylinder cover. Buy new pistons, relief valve, and pump suciton and discharge valves. When rebuilding pump I honed old cylinders and lapped in new valves. Make sure your cylinders have not cracked due to neglect or freezing. For the lift cylinder, from 1939 to 1952 they used a cast piston ring. In 1953 they went to rubber o-ring and leather backing ring with great results. These pieces will fit your 1948 too. I purchased new components here. There will be allot of crud in the housing, clean this out real good. There is no filter, and you do not want to ruin the components you just installed. I cannot stress this enought, clean the inside well. If you live in a northern cold climate, you will want a tractor/transmission/hydraulic fluid that meets FNH134D (Ford/New Holland). You can get this at New Holland, Case, John Deere, Kubota, NAPA, TSC, Ruaral King, etc. Just get a fluid that meets FNH 134D. This rebuild should last another 60 years! Philip.