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Failed, or failing, hydraulic reservoir cap?

2K views 11 replies 7 participants last post by  zuren 
#1 · (Edited by Moderator)
I deal with a constant film of hydraulic oil on and around the hydraulic fluid reservoir under the seat. I can't find any active leaks with the hoses so is this oil that is getting past the cap? I inherited this tractor from my dad and that area has been an oily mess for as long as I can remember. I tried cleaning everything up but it didn't take long for it to become messy again.

Just wondering if anyone else has encountered this issue and if the fix is simply a new seal in the cap or if it is something different.

Thanks!
 
#3 · (Edited by Moderator)
Sounds like the tank needs an elevated vent?

Some pipe, and an airtool muffler outta fix that. Cheers:)
The cap on the reservoir has a hole that I'm assuming was intended to be a breather/relief valve. Would it be a fair assumption that the seal in the cap has lost its ability to breath, so that breather hole is no longer working, the tank is getting pressurized, and blowing oil out from around the cap?

Before I start drilling and hacking, I would like to have a good handle on the cause. Maybe a new cap seal is the answer.

Thanks!
 
#6 ·
What style of cap is on it?
I'll post a pic later, but it is a fairly standard screw-on cap with a small vent hole in the middle. I believe there is some type of seal on the inside.
 
#7 ·
Not familiar with your tractor but don't believe the fluid should be at the cap. The job of the cap is to keep dirt/water/etc. out, not keep the oil in.

You need to set the level with the cylinders collapsed because they return more fluid to the tank in that position. Then there needs to be enough room for thermal expansion too.
 
#8 · (Edited by Moderator)
Hi the tank maybe overfilled the 1976 manual days to fill the tank to just above the the bottom of the hose inlet the newer manual says to fill the tank to 1.5" below the top of the tank, its a simple cap with a baffle with a vent hole and a vent hole in the top of the cap, with a lot of use the hyd oil is rushing in the side of the tank and some of the oil maybe vaporizing and going out the vent. All of my have some oil residue but not what I'd call a lot.
 
#10 ·
I had a similar problem, fluid everywhere, from the cap. I have a friend who owns a hydraulics repair business. He asked me to inspect the installation of the new hoses, overhauled pump, and cylinder he did, for leaks, and to look at the fluid in the reservoir to see it was foamy. No leaks, but the fluid was foamy, pushing through the offset cap seal. Turns out I had over tightened the lines to the pump and cracked the pump fitting boss, allowing it to suck air, but not leak fluid! New pump, all better. Not sure if this is what you have going, but he said look at the suction line fittings, the one that feeds the valve... Good luck!
 
#12 ·
Thanks for the replies. In the next day or so I try to take a closer look.
 
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