"bob" wrote:

A liquid filled gauge is of good quality and should hold steady not have needle vibration.
Later Bob

I'd say then the deviation is coming from a small suction leak. The pump seems to have a sort of high pitched whine to it.I'm taking the fitting off tomorrow on my lunch break.

I switched out the o-ring for the fitting, and that fixed 90% of the needle deviation in the guage, but I still got a little still.I think it may be the o-ring behind the plate that the fitting screws into. There is 2 fasteners holding the plate on but I can't seem to get a socket to fit them.I dug the dirt out around them, but couldnt get nothing to hold. Any ideas?

Are they 12 point bolt heads? They use them in restricted spaces.
Later Bob

Craftsman and probably others make a worn bolt/nut removal socket set that will grip stuff that even a 6 point socket won't hold on. It does help to have some height to work with though. I have a set that I got for Christmas, and it seems to have a skip in the sequence of sizes so that it is missing the one I most often need.

"bob" wrote:

Are they 12 point bolt heads? They use them in restricted spaces.
Later Bob

I bet you hit the nail on the head or should I say bolt.LOL ccjersey ,I dont believe anything is worn off, but that is good info to know. Thanks Guys

Hi,

I have been reading the Cat 955l wont push under heavy load thread between bob and pmp daddy with interest. I have a 955l with the same issue. I took the pumps off like stated and it was obvious that someone had done the same job shortly before I got the machine, it had new bots, washers, etc.

when I got to the seal between the steering pump and the trans pump. It looked like it was in backwards to me. The broad flat side of the seal was toward the trans pump and the rubber seal part was toward the steering pump. I looked at my parts book and it show the seal in the way it was installed, but looking at the service manual shows the seal should be in the other way with the rubber lip toward the trans pump and the broad flat shoulder toward the steering pump. This way makes more sense to me. Can you tell me which way the the proper way for that seal to be installed.

thanks
sidney smith

Sid, the seal lip should face the steering pump. If the steering suction screen located beside the steering pump suction line gets clogged up the steering pump will draw oil from the trans pump through that seal. Trans oil will go down and the steering clutch oil will go up. What condition where your pumps in?
Later Bob

I looked in the 955L parts book and see the seal lip facing the steering pump side.
I don't have a service manual to compare but I believe the seal lip would face the higher operating side. eg. my early 955 manual shows a transmission pressure of 300 psi max. and a steering pump pressure of 350psi max.

What does your manual give for pressures?

The preferred design seal for this application would be a double lip (two direction) unit. Maybe your service manual shows an upgrade.

Hi Team,
the seal lip must face towards the Steer pump as the pump housing is drilled behind the pump shaft/gear bearings to relieve leak by pressure oil from the shafts. The drillings are connected to the inlet port of the pump and is therefore at a lower pressure than the outlet port and the bearing cavity ends. Leakby of the bearings is desired to both cool and lube them, if the cavities were not drained oil would build up here and not flow through between the bearings and shafts causing heat build up and possible seizure.
Thus the seal feels low pressure and must seal out air and steer pump oil from the cavity between the pumps. An incorrectly orientated seal lip will allow the seperated compartments to transfer oils.
Hope this helps.
Cheers,
Eddie B.