Ford 555 from the 70s - hydraulic leak below right foot

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For those of you familiar with the old 555, the three main hydraulic lines for the excavator run next to the right side frame. One of the three, T's into the frame via a threaded fitting at the spot where my leak is occurring.

I have a leak at the T. I cant quite tell if the leak is from the frame, or from the T fitting/rear pipe, but the frame will drip with fluid. I guess there is a possibility of a pin hole or crack in the frame.. it appears to leak when running so i suspect a pressure related issue.

1) does anyone know the fitting size at the T? The rearward pipe at the T has a dent just behind the female thread coupler that may be the issue. I'll just have a line made to replace the pipe. Curious if anyone knows the size of that line and ends, so i can stop and have one made without removing anything.

2) is the extra reservoir of the frame required? If there is a leak in the frame section the T is screwed into, can i remove the T and just run a straight coupler?

Thanks

 

[Fritz Maurer]

1970s? Sure its not a 550? Makes a difference

 

[Sean in PA]

The 550 was made from 1975-1978 and the 555 was made from 1978-1984, so either could be "from the 70s".

From the parts drawings, I only see one tee fitting in the lines for either one, and they are both listed as 1-5/16"-12 threads with 37 degree flare ends.

 

[Fritz Maurer]

Does it look like this?

 

[[email protected]]

Exactly! Yours is in better shape, as my mount is no longer holding the pipes. Looks like someone replaced one of the pipes with a newer hose on mine, and never put the pipe mount back together.

That T at the far left of the photo is where mine is leaking... still cant tell if its the section that screws into the frame, or if its the rear pipe connection.

 

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Thank you Sean

 

[[email protected]]

Interesting! I had thought it a 555... but now that i research it, i see i have a chain setup for excavator rotation. This would tell us its a 550, correct?

 

[Fritz Maurer]

You cannot eliminate that tee. It crosses over to the other frame rail and returns up the side of the radiator to the filter housing. Need to disassemble that tee and find out what is wrong with it. A crack in the frame is unlikely unless you break up concrete with it.

 

[Sean in PA]

(quoted from post at 08:38:40 09/06/23) Interesting! I had thought it a 555... but now that i research it, i see i have a chain setup for excavator rotation. This would tell us its a 550, correct?

Most likely, but the best way to tell would be the model number, either from the sticker on the under side of the hood above the battery or stamped into the flat spot near the starter, which is probably hard to get to because of the loader frame being in the way.

 

[Fritz Maurer]

A lot of times the steel lines work the tee when you run over trees or dirt or some other wreckage that you shouldnt be driving over. The tee is boss o-ring into the frame, and if the tee starts wiggling it can tear the o-ring and start it leaking, even though it is mechanically tight. I suspect thats why the former owner changed it to a hose: he either ran over something and damaged the line, or the clamps or adjacent lines rubbed a hole in it.

 

[Fritz Maurer]

That, or a 4500

 

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Thanks Franz. The rubber couplers that run across to the other side are getting old. I'll need to replace those as well.

 

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thanks FRITZ!

(I have a coworker named Franz, rolled off the keyboard)

 

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Its 100% a 4500 with a backhoe. Learning a ton from you all. appreciated!

 

[shaun wallace]

On the 2 4500s I have the fitting where screws in loader frame is pipe thread.

 

[Sean in PA]

The tee on a 4500 is a different part number than the one used on the 550 and 555, plus the description is different as well. It just says:


3 WAY CONNECTION
Tee, 1'' Tube, U.S.;No Longer Serviced.; (Prod Date) Between 01-Jan-1965 and 30-Apr-1971

So it is most likely 1" NPT where it goes into the frame as Shaun suggested, but the other two connections are listed as 1-5/16"-12 37 degree flare fittings.

I went back and looked at the tee on the 550 and 555, and that one doesn't actually connect directly to the frame, it connects to 3 separate lines, one goes to the filter, one connects to the return from the backhoe and the other connects to the loader control valve, most likely to the return port there as well, so it tees the returns from the loader and backhoe together and sends them to the filter before the fluid returns to the reservoir. The one on the 4500 looks like it does the same, but without going through the filter, so that's why it connects directly to the loader frame, as that is the return point back tot he reservoir.

 

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Once again, thank you Sean