The 955H, I just bought, steering assist just quit working after I shut it down, started to go back to work, no steering. I removed the strainer, strainer very clean. Filled the tube going to pump with 30 weight still no steering, tried twice, Was steering good until I shut it down for a few minutes. Any suggestions? does the fluid flow from the pump through the strainer or the other direction, from strainer to pump?

Fred

You mentioned checking the strainer....there is also a filter to check but it does have a by-pass valve.
There is also an air bleed passage located in the center pin of the filter. Make sure the passage is clear to allow complete filling of the filter.
Flow is from bevel gear compartment to the bottom of the strainer, out the top of strainer to pump and from pump to filter then to steering boosters.
What serial number are you working on?
The pump is a 9 GPM minimum at 1940 rpm at 350 psi.
The clutch control relief valve (for pedal steer) is 550-650 psi.

Hi Fred,
not unknown for the suction lines to rust through and the resultant air leaks stop the pump from piming up, also the short hose between the screen and pump inlet goes hard with heat and age, therefore not sealing properly with the same result.
Always prime the pump with oil before starting after the oil has been changed or the pump refitted, they are notorious for seizing up afterwards.
Oil level may be low also.
The 0.04" dimesion given in the pump pic. is the distance down for the end of the pump shaft bearing otherwise the bearing lube is cut off and the pump shafts will seize. This is relevant to ALL Cat gear type oil pump bushings.
Sorry about the lines pic. but it was scaned at 600dpi and will not play the game.
Cheers,
Eddie B.

Eddie:

Thanks for the information. I'll check for rust and leaks at the lines.

Thanks,
Fred

Hi Fred.
Got your PM....that's been a tough machine so far.
No doubt you have a suction leak.
I'd be suspicious of that 5H7370 seal.
No, I don't know of any quick way of checking other than close inspection....pretty hard to get a pressure check with the dip tube going into sump.

I really appreciate all the help you guys provided. I started with the easier work first by replacing the hose, cover O-ring and the spacers were missing from below the filter, so I replaced the spacer. Primed it and the steering assist began to work, but works best at high RPM's,1/2 to full throttle. I am going to check the filter tomorrow, see how it starts and works tomorrow. Probably will quit after I heated it up today and let it set overnight. Trying to avoid replacing the seal Old Magnet suggested was the problem, unless there is an easier way than I could detemine to get to it to replace. I do have another question, where is the serial number located, I have assumed the seller was correct about the serial number, but since it was advertised for sell as a 1974, actually a 1963, according to Yancy Brothers it finally dawned on me I really don't know what I got. Thanks again for your responses.

Thanks,
Fred

Serial number should be on the back of the transmission/bevel gear case just above the LH brake access cover plate and on the LH rear of the engine just below the cylinder head. The numbers should be on tags attached with drive pins but may be stamped in those locations if the tags are missing.

I'm curious....where did the 60A6144 sr.# come from???

Old Magnet:

The seller had the serial number listed with the 955 in Equipment Trader Online, also had it listed as a 1974. I checked the block below the cylinder head, no tag, no stamped number. I also removed the battery located below the fuel tank (upper battery located below the left arm rest) didn't see a tag or number. There are weights bolted on below the battery compartment, I really don't want to remove these unless that is where the serial number is located for sure? I did locate a tag on the left side of the engine, above the voltage regulator, at the rear end of the generator. The tag is damaged, I could read the numbers 60A614? with an H below and to the left of the numbers. Do you think a number is stamped behind the tag?

Replacing hose, o-ring, filter and o-ring didn't fix steering, I am going to have to replace the one you suggested. Do I have to remove the tank and other components above the seal to get to it. I have another couple of question concerning number 4 cylinder, can the piston, sleeve and rod be replaced without removing the engine? Do you think it should take over 120 hours to remove engine replace sleeve, piston, head, replace engine and test?ect.

Fred

Hi Fred, the 60A series was produced from 1960 to 1967, the book I have agrees with the date of 1963 that you were quoted for that serial number.

It sounds as though you have found the serial tag....though not where it would usually be ( if I'm reading your post right).

Hi Fred,
Had to do a little homework to answer your questions.

On the sr. # tags....no guarantee any of them are in place or stamped. Just going by the normal locations.
No, I don't think it would warrant looking under the tag you have for a stamped number as that is not the normal tag location.
The fact that the sr. number plate has been fiddled with usually indicates the engine has been changed......and in this case it seems the original plate was retained but in a different location (just guessing)

The D330a engine (right for the sr. #) will have the four-bolt rocker arm cover and belt driven water pump.
I don't remember if your unit was peddle steer or not, it would have been an attachment option for your sr. # and became standard at sr. #60A8413

On the filter screen line you will have to remove enough stuff to get access. Probably have to remove the filter housing and line as a unit then separate. As edb mentioned check line for rust holes. The access to the case suction line is pretty nasty. Everything on top of the case cover would have to be removed. The elbow appears to be part of the casting. Before doing that one I would check the pump for condition and make sure the double lip shaft seal is in good order. (see pump attachment)

I checked the service manual and it states that rods, rod bearings, pistons and sleeves are removable without removing the engine (access through side cover). It still would warrant an eyeball check as #4 cylinder sometimes has limited access due to loader cross members. In any event it's a real exercise to work on. Might make sense to pull the engine.....in fact I would be inclined to do so as the D330 & D333 engines were famous for spinning bearings (unusually rods, sometimes mains) so now would be the time to check things out and engine would have to be removed to access the crank...your call.

The one thing I can't help you on is the time required as I don't do this for a living. Considering it is a loader and there are some unknowns
120 hrs may be in the ball park but seems a little excessive although I'm sure it would take me by myself all of that and probably more.