Ford 1520 blowing Hydr Filter Seal

mrbrettbaker · Mar 9, 2011

Rick, the only reason I posted a different thread was because I thought I had given the wrong information about what the filter was ( thought it was hydraulic system) and thought if I had HST I might get some responses.In fact I got a great explaination as to how the system operates.
That being said, my story is straight, but I guess multiple posts might confuse it. I'll say it again. Friend went to dealer, got the filter you gave me the number for. Did not fit!!! Center hole was too small. He returned it to NH dealer, THEY gave him wix 557088! He never asked for or mentioned this number. They said this was the 'other' filter.
Now that I've been beaten up for multiposting ( deserved) and for not having my story straight ( undeserved) I will try to contribute to this as I diagnose and repair this. All this expert opinion about failed filters has me looking at it differently. Why did the original ( wix btw) last years and now it won't stay on? I will post pics when done. I removed the housing from the tractor. On inspection it looks like the oring makes contact outside the polished surface and seats partially on the paint and rust. Unfortunately I disposed of original filter but I suspect with all the filter upgrades and changes they may have gone to a larger diameter seal. I also spotted that I could tighten it until the metal cannister lip made contact. I machined a small amount off the outside circumference to allow it to clear so I might tighten the filter a little more. Should the filter not be the problem I drilled and tapped the housing to accept a gauge to check line pressure. Should there be a problem with the HST we will not spend the money to replace it, I will put a bypass valve in my tapped hole and vent a little pressure back to the tank. I will post pics as I go
thanks for the help, bullied or not! ;-)

RickB · Mar 9, 2011

The Wix website does not list a 557088 filter. If I am being a bully, I'll just go away.

mrbrettbaker · Mar 9, 2011

Lol, was kidding about you giving me crap (appropriately) for multiple posts. Your right, wix calls it a 57088 but what is really funny is the NH dealers filter has 557088 on it with no name and the napa 7088 has the same exact 557088 and flag on the filter! Honest, thanks for the help Rick

mrbrettbaker · Mar 9, 2011

Lol, was kidding about you giving me crap (appropriately) for multiple posts. Your right, wix calls it a 57088 but what is really funny is the NH dealers filter has 557088 on it with no name and the napa 7088 has the same exact 557088 and flag on the filter! Honest, thanks for the help Rick

jinman · Mar 9, 2011

The correct filter for your tractor is:

FILTER
Filter, Oil, HST, Start Year: 01/01/1987
SBA340501030
1 Needed for Job
$26.91 In Stock : 30

Below is a diagram of the hydraulic and HST piping.

6sunset6 · Mar 9, 2011

my two cents and I can be wrong. I have a tc34da and this is from the manual. HST different but probably not that much.
The charge pump on the HST takes suction oil after the hyd filter.
The charge pump relief valve is set at 61-81 psi. or maybe 75-95. Numbers are different in different places. Flow is to the cooler and then to the HST filter and then to the HST center section.
So the HST filter should never see more than 95 psi. If the filter is not seated right 95 psi could do it. The bypass over the charge pump relief valve is back through the cooler.
Side comment.
I always thought hyd filters were in return lines with just screens in the suction.
I wondered how these tractor systems controlled the dirt that comes in with quick disconnect on and off frequently. Now I see that the main hyd filter is on the suction line and the HST filter is after the charge pump. There is a lot of protection from what ever is in the tank.