Are CAT Hydraulic Pumps Special to CAT?

[ThatGuysFarm]

Are CAT C-flange pumps different then every other C-flange pump? I have a CAT pump drive diverter from a 773B haul truck with a 3412. The diverter is run off of a driveline yoke out the back of the left head. The diverter had 3 gear pumps mounted on it, 2 with a 2 bolt C-flange mount and 1 with a different mount. We designed an adaptor on the oddball mount to except a 2 bolt C-flange pump and got it milled out on a CNC mill. The goal here is we are going to need to run 3 load sensing, piston pumps on the diverter drive. When we went to bolt on the new pumps the input shafts of the pumps only engaged the splines in the diverter by 3/8". I didn't think about the shaft length being an issue, I thought all SAE C-flange mounts were universal. The new pumps have a 2.187" long input shaft and the old CAT gear pumps have a 2.875" input shaft so the new pumps are about 5/8" shorter. So my question is now, where can I get a load sensing, closed center, piston pump that has at least 55gpm that will bolt up the a CAT C-flange? I found some info that said CAT 773D and 773E trucks have load sensing pumps 219-1964, Rexroth # R986110187 but I am not sure if they have the longer shaft or if the are "normal" C-flange. I'm looking for ideas, every time you ask CAT they need a part number or serial number, I don't have any of that... Yet

 

[Welder Dave]

Cat may have specified a longer shaft for their application.

 

[Coaldust]

Their Tyrone and Vicker style gear pumps are fairly generic. You could use the Eaton catalog and find something that would work. My son calls it catalog engineering.

 

[chidog]

Tyrone, brought back some memories.

 

[f311fr1]

Look at Hub City for spline shaft adapters to achive the length. A lot of older Vickers vane pumps would have non catalog type shafts or displacement rings.

 

[Mobiltech]

Why can’t you get your mounting flange machined down on the face by 1/2 an inch. You will also need to drill and tap the mounting bolt holes deeper into the cat flange.

 

[f311fr1]

Can you stack two pumps and us a third as a single? block off the odd mounting flange on the pump drive. Mak all three pumps thru drive and block of the rear faces of the single and rear pump of the stack of two. That way all 3 pumps are the same and you only need one spare. I used to do it all the time on industrial HPUs

 

[f311fr1]

Tyrone, brought back some memories.

Corinth MS. Geartek in Corinth is a direct decendent

 

[ThatGuysFarm]

Why can’t you get your mounting flange machined down on the face by 1/2 an inch. You will also need to drill and tap the mounting bolt holes deeper into the cat flange.

I have look and thought about doing this, the pump diverter I'm using mounts 3 pumps on it. One of the mounting spots could be machined down with plenty of strength left, another would be on the edge of strong enough and the third can't be done and still be 100% confident that the pump won't eventually break the housing.

 

[ThatGuysFarm]

Can you stack two pumps and us a third as a single? block off the odd mounting flange on the pump drive. Mak all three pumps thru drive and block of the rear faces of the single and rear pump of the stack of two. That way all 3 pumps are the same and you only need one spare. I used to do it all the time on industrial HPUs

We have looked into the stackable pumps some, I have not gotten a straight answer if the will fit this mounting surface or not, and no one that sells them wants to go measure a shaft for me. I love the idea of all the same pumps, I would be pretty tight on enough room for stacking the pumps but I think it would fit, I don't know why this drive box has a different mounting depth then all the pump specs I can find. Maybe it was some odd ball thing that CAT did, but I have not been able to find a CAT mechanic that knows either.

 

[f311fr1]

55 GPM at what pump rpm? What PSI range?

 

[ThatGuysFarm]

55 GPM at what pump rpm? What PSI range?

Pump will run 1:1 with engine RPM so 2100max, and 3000psi minimum

 

[f311fr1]

Look at RR A10VSO 100 DFLR 31 * V U C 62 K07. Need to know shaft rotation when looking head on to the input shaft. Max pump RPM = 2000. 6.1 CU IN per rev @ 2000 RPM = 52.81 GPM the extra long shaft might be a 17 tooth CC shaft. Look at the catalog

 

[westerner]

My son calls it catalog engineering.

Best reply I've seen all day.