D5B Hydraulic Pump Rebuild

[Ferdinand]

My hydraulic pump is leaking into the crankcase now that I've re-sealed the tank and return lines properly. I see in the CAT parts book that there are two lip seals that can be replaced, but there are no other parts shown for the pump, except for a "rebuild kit" PN: 9J765. I don't see how you could remove the old seals without splitting the pump apart. The pump body clearly needs to be resealed, but there are no gaskets / seals shown in the parts book.

So, what am I missing. Does the rebuild kit have the required additional parts? Local dealer doesn't seem to have a clue besides "just buy the kit and find out".

 

[Old Magnet]

The 9J765 kit says it contains seals and retainer.
That should include the shaft seal and possibly an "O" ring for the pump case joint.

 

[kshansen]

If you order the seal kit don't forget the 5F-3106 seal for mounting the pump(that number does change to a 175-7904).

Also unless you have a good assortment of orings one of 4J0522 seals and one of the 4J0524 seals and if not replaced recently 11.5 cm of 5P1292 hose for the suction line.

 

[Ferdinand]

Thanks for the replies. Looks like it's a Parker 20 series hydraulic pump. Already have the front lip seals and body to accessory case o-ring. I'm assuming that the hose end fittings to pump body are both standard code 61 sizes and I have tons of orings for them. Never reuse orings when I break things apart.

Suction lines are brand new. Actually had to use OEM parts for that, as they appear to have enough flex to seal right. Generic hydraulic return hose of the same size would not seal against the pipes, even with T-bolt clamps, not to mention starting to disintegrate in the sun in under month...

I'm not inclined to buy the kit just to discover what is in it. For stuff like o-rings and seals, I've taken to measuring and ordering parts of my own specification. That way I can decide to use high resiliency Viton on an o-ring ring rather than paying 5x for a generic buna-N part from the dealer. Not too fond of fixing stuff multiple times and been burned by quality issues with OEM heavy equipment parts way too many times.

 

[Nige]

Tomorrow I’ll take a look in a resource that I have and post the breakdown of the 9J765 Kit.

 

[Ferdinand]

Thanks, that would be greatly appreciated.

Have the pump apart and it looks like there is an o-ring for the body and another cut o-ring type seal against the rotor plate as per the picture.

The lip seals were hard as rocks and of course wear groves in the shaft that I'll need to sleeve. The drive gear was actually loose even with the bolt tightened down. Looks to be about 0.002 too short for the given shaft size. Wonder if someone forgot to install a bottom washer or used an incorrect top washer that is suppose to be domed. Be interesting to see if there are parts missing.

 

[Nige]

I can pretty much confirm what OM posted above. The info is hard to track down but it seems as though the kit only contains the joint o-ring and the shaft seals. The problem is that there are no separate P/N's for the internal parts of the pump which makes tracking down info a bit of a challenge. Out of interest did you ask for a price on the kit..?
There is a procedure for installing wear sleeves, Cat reference SMHS6915
"Installation Of Wear Sleeves For Repair Of Groove Wear Caused By Lip-Type Seals"
I'm not sure if some or all the info in it might be of help to you.
Regarding the gear slop, is it possible that someone used an incorrect lock or washer under the bolt head..?

 

[kshansen]

The biggest problem I see with trying to used the repair sleeves on this pump is the shaft were the seals ride is the same diameter as the section where the bearing/bushing rides.

The only possible way to way to install one of those sleeves would be to install on shaft after pump was assembled and before the seals were installed in housing. Not saying it would be impossible but....

Is there by any chance a Cat part number stamped in the pump housing? Something like a 3G4661 ?

Parts were at one time available for these gear type pumps but it took a lot of digging to find the parts break-down information on them. Most parts books would only show the seal kits but with a good parts person and some work I was often able to find parts right down to the bushings pressed into the housings along with all those other parts like the brass plates and plastic bits behind them!

 

[Ferdinand]

The price of the kit was just a few dollars more than the two lip seals, think it was right around $40. That's why I didn't think it contained any of the internal parts. I have o-ring cord coming to re-make the interior high to low seal and a guess at the closest dash number oring for the two halves of the case.

The distance between the lip seals requires that two sleeves are needed to fix the groves in the shaft. I have not been able to find a copy of SMHS6915, but I expect it covers using multiple sleeves and filling in the grove with epoxy before installing the sleeve due to the pressure the seal will exert on the shaft during operation.

I'll post the part numbers I used for the internal parts and some pictures once I know everything is working right. The leals seals from CAT are made by SKF and obviously Viton. Had a CTP branded seal with the same PN sitting around and it's made of soft buna-N. That would have not lasted very long given the pressure and temperature the pump runs at.

 

[Ferdinand]

Good point about the sleeved area having to pass through the bushing in the front housing. If sleeved from the front after assembly, the housing becomes captive. Looks like there is only about 0.001 clearance between the shaft and bushing, not enough to pass a sleeve. Might make more sense to try and shim the seals to a different location as there is 0.106" from the top of the outer seal to the end of the housing.

 

[kshansen]

Well if that is an 8J6330 pump it appears many of the other parts are available. I did check and some say contact dealer but most do show a location.


Just an example gear 9T1269 shows as being $153. and gear 9T1259 shows as $230 then the seal kit # 9J4729 is $73.

 

[mitch504]

just curious, what does npr mean?

 

[kshansen]

just curious, what does npr mean?

I could be wrong but believe it's:
Numerical Parts Record

That is Cat Speak for "Look Here For More Information!"

If you are viewing that page in SIS and you click one the "NPR" it will take you to a page that may give you anything from the new part number that replaces the one shown, a link to a article on a "Special Instruction" that lists that part. If you have higher level of access than I do you can also see service bulletins about that part.

 

[mitch504]

gotcha, thanks

 

[Ferdinand]

Interesting... Do the isolation plates show as being available? 4T9425 and 4T9426. The pump has 4 parts in that location. An aluminum plate on one side, two plastic parts and a rubber seal on the other. Question is, does the "isolation plate" include all 4 parts or just the aluminum plate? The isolation plate and pressure plate show a gap between them on the diagram that is not present on the pump, perhaps an error or attempt at making the illustration clearer?

 

[kshansen]

It gets to be a little confusing here when checking on the isolation plates it says contact dealer. As for the rubber or plastic parts in that area I'm thinking they would be in the 9J4729 seal kit. But I can not find anything that gives an actual break down on that kit number.
If someone else reading this has access to Service Magazines it appears there are three that relate to the 9J4729 kit:
SMNV0689
SMFE1290
SMJL2897

Not sure about the way the parts book makes it look like there are three things stacked up there but my guess is they are showing the pressure plates as two parts, they are seal backings with a bronze layer on them against the gears.

Another thing is the pressure plates is a bit more confusing where the pump shows two of 9T1276 when I run that number it comes up with two different numbers. 364-6564 and 364-6565.

Sorry I can't be of any more help

 

[Nige]

The D&A procedure for the pump certainly makes mention of multiple plates during the process.
To the OP, you said above that you thought the pump on your machine was a Parker Series 20. I'm thinking that the 8J6330 pump is more likely a Tyrone pump, but I may be wrong.
Attached a couple of docs that may be useful.

 

[Ferdinand]

It probably is a Tyrone pump, but Parker bought them as far as I can tell, so whatever the Tyrone PN was, it's probably been changed, or the pump replaced by something Parker makes.

I'll have the parts to try and re-assemble it tomorrow and let you guys know how it goes. The isolation plate seals are still somewhat pliable, so I will reuse them if the oring stock rubber doesn't work out.

I think I will try moving the inner seal lower to move it's contact points out of the old groove and move the outer seal further out to do the same. Or I may
install the two sleeves after the pump is together and then press in the seals over the shaft.

Thanks again for the help.

 

[Old Magnet]

I'd be adding up the individual parts cost if it gets out of hand. That's a common pump used on the 3306, 977, D5, D5B. I see complete after market pumps as low as $700.

 

[mikebramel]

Yeah Permco would be at that price or maybe less