CAT E70B hydraulic problem

[jim weaver]

I've seen threads like this one while browsing, but I have some additional questions.
my E70 is dead on one side (hydraulics, right track, bucket and boom). I have switched the pump output lines and the problem moves to the other functions, so I have a bad pump, right?
here's what I'm having trouble understanding...there's only one pump in this machine. an uchida a10vd43 has a single rotary group, and since some functions are strong, how can that pump be bad?
thanks,
jim

 

[bindian]

Is it a E70 or a E70B? My E70 has two pumps. One attached behind the other.
hugs, Brandi

 

[dcomp]

I had the same exact problem and same pump on a cat 307ssr grey market it is a dual pump with 2 rotating assemblies internally. Mine had a broken ring that holds the Pistons in place and let all the piston heads wear. I've had a terrible time trying to find anyone to fix it reasonable

 

[jim weaver]

this is an E70B. there are 3 stacked pumps, the hydrostatic pump, the pilot pump and the blade pump. exploded views of the hydro pump show a single rotating group, and the parts list for the pump indicate the same single rotating group.

there are 2 outputs from the hydro pump, but I cant find an exploded view of the entire pump to see how the flow is split.

brandi? are you saying that your machine has 2 separate hydro pumps? or that your pump has 2 rotating groups internally?

dcomp? do you know the model # of your hydro pump? everything I see on the net lists the same uchida a10vd43 for the 307.

thanks,
jim

 

[jim weaver]

this is the exploded view that I am going by:

http://www.screwmax.com/index.php?p...com_virtuemart&Itemid=173&vmcchk=1&Itemid=173

jim

 

[bindian]

this is an E70B. there are 3 stacked pumps, the hydrostatic pump, the pilot pump and the blade pump. exploded views of the hydro pump show a single rotating group, and the parts list for the pump indicate the same single rotating group.

there are 2 outputs from the hydro pump, but I cant find an exploded view of the entire pump to see how the flow is split.

brandi? are you saying that your machine has 2 separate hydro pumps? or that your pump has 2 rotating groups internally?

dcomp? do you know the model # of your hydro pump? everything I see on the net lists the same uchida a10vd43 for the 307.

thanks,
jim

Jim,
I have two pumps connected back to back. Not sure if they are on a common shaft or some time of coupling inside.
hugs, Brandi

 

[jim weaver]

brandi, are those 2 pumps in the same housing? or are there 2 pump housings stacked?

thanks,
jim

 

[bindian]

Two pumps stacked. I don't have a pilot pump.
hugs, Brandi

 

[jim weaver]

ok, thanks brandi. that's a different setup than mine.
I have a single hydro pump on the back of the engine, and then the pilot pump stacked to that.
what I need to figure out is, whether or not that drawing is correct and there is only a single pump inside of that housing or if there are indeed 2. if there is only a single pump, then the flow must be split to the 2 outputs. one output is dead, the other seems to have sufficient flow and pressure to operate its' half of the machine.
I'm hoping to get a definitive answer to that question before I pull the pump.
jim

 

[lantraxco]

Dunno from the E70, but typically the Japanese pumps with two outputs from a single rotating group the flow is split at the barrel and valve plate, they're ported to flow every other piston to each outlet basically.

 

[jim weaver]

thanks lantraxco, that would make sense, except that there are 9 pistons.
there look to be 3 or 4 outlets on the valve plate, maybe they split all piston outputs inline?
jim

 

[lantraxco]

I think that's a generic picture, this one shows 10 pistons?

 

[jim weaver]

ahhhh, thanks for that! what sight is that from? that also shows 2 rows of ports on the valve plate.
looks like maybe valve plate scoring is a possibility now.
any good parts sources for these pumps?
thanks,
jim

 

[dcomp]

There are 2 rotating assemblies on the shaft facing opposite each other sharing the swash plate. The broke ring and piston wear I was telling you about. Where I ordered my parts from. Other life problems has brought my project to a halt so I can't vouch for the quality of the parts other than looks good

 

[dcomp]

More pictures for your viewing pleasure.

 

[jim weaver]

wow, thanks for those pics.
so that blows all of my previous assumptions out of the water.
did you order from a u.s. dealer or directly from handok?
thanks,
jim

 

[jim weaver]

thanks for all of this dcomp. you have provided the definitive answers to my questions.
all I need now is to tear it down and get some parts coming.
so did you order from a u.s. dealer or handok directly?
jim

 

[lantraxco]

Learn something new every day, I stand corrected!

 

[dcomp]

I ordered from them from Korea. You can find the parts here but it seems like Noone really wants to deal with the grey market machine and prices accordingly. I can't remember the website I found them on its been awhile since I've studied this stuff. I also found a manual it's for a kobelco but it has the same pump. I'll study on how to send it to you. It is on my phone at the moment

 

[jim weaver]

thanks for everything dcomp. too bad we're not closer or I'd come help you reassemble that machine.
lantraxco, thanks for your help too. although it wasn't applicable to my current situation, I learned about the pumps that split their output via the valve plate. might come in handy on another project.

http://www.hydraulic.co.kr/ that websitelooks like it's gonna be a bear to navigate, and I'm not looking forward to ordering from korea too. anyone have any u.s. sources?

jim