Author Topic: Hydraulic pump leak  (Read 2496 times)

Roy Boles

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Hydraulic pump leak
« on: May 27, 2020, 05:12:22 PM »
Hi everyone. My hydraulic pump has decided it wants some attention by leaking. Anyone know which pump Beaver used on the 1998 Marquis?
'98 Marquis Diamante
C-12/Allison 4000

Jerry Carr

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  • 06 Pat. Thunder Cat. C13
Re: Hydraulic pump leak
« Reply #1 on: May 27, 2020, 09:10:22 PM »
Not sure but BCS could tell you I had mine rebuilt and it was good to go. You may want to check with a shop near you one advantage in a rebuild you know it will fit.
Regards,
Jerry Carr
Past Region 1 V.P.
Entegra Anthem
06 Pat. Thunder Cat C13

Roy Boles

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Re: Hydraulic pump leak
« Reply #2 on: June 14, 2020, 06:21:28 PM »
 I’ve replaced the fitting O rings on the pressure side and the O ring between the pump and the gear case. Picked up O rings from the cat dealer. Hopefully the leaks are a thing of the past.
'98 Marquis Diamante
C-12/Allison 4000

Jerry Pattison

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Re: Hydraulic pump leak
« Reply #3 on: June 15, 2020, 05:26:49 AM »
Roy, is that the pump that drives the cooling fan?

Dave Atherton

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Re: Hydraulic pump leak
« Reply #4 on: June 15, 2020, 12:29:22 PM »
Roy if the hyd motor that drives your radiator cooling fan is going bad how you can verify this problem. Looking at your hyd fan motor and you will see a pressure going in one side and hyd hose across pump housing return hyd hose fluid to tank. Ok now there is one more hyd
hose either on end of hyd motor housing or in center of hyd motor housing. This hose is called case drain and what that means to you.
Disconnect that hose from hyd motor body and start engine hyd oil will discharge from fitting on hyd motor that is telling you your hyd
motor is going bad and hyd oil is bypassing going to what is called case drain. Depending on who built the hyd motor, some can be rebuilt
and some requires replacement. Ran into this problem several times and some of these hyd motors have been discontinued and built
across the pond . my suggestion caterpillar has many different hyd motors that can be retooled to your motorhome fan mount that may
be of interest in case this fan motor replacement gets real involved. Dave Atherton Retired Cat Mechanic