Backhoe main hydraulic pump leakage.... EVEN AFTER REBUILD!

jenkinsph · Mar 22, 2015

Tx Jim said:
If pump shaft has too much end play then this can cause pump shaft seal to leak. I disagree with b&d as I own a 4255 with nearly 11,000 hrs that the pump doesn't leak and hasn't been touched since it was new. I also own a 4440 with 10,000 hrs that hyd pump doesn't leak.

I agree that the seals will often leak because the bearings have too much wear and play. The rebuild may have only been a seal kit not a full repair.

muchtooffer48 · Mar 22, 2015

I guess what was done to the pump will be unknown until the time that the pump is gone-through again, because the man I bought this from has passed on. Checking the pressure as one of you nice folks suggested will tell the condition of the pump. And be a great place to start. From memory, the hoe worked fine, it just leaked all over everything. I tied ply underneath the machine so I wouldn't get arrested. And that worked fine for just moving it around, but I will have to repair before I can really use the machine. Thanks Guys. Frank.

buickanddeere · Mar 22, 2015

If there is a hydraulic problem with low or no high pressure system flow. 95% of people install a new or rebuilt front pump when there was nothing wrong with the old pump. The front pump will only pump the oil supplied from the transmission pump. Transmission pump, filter, valve, pipework or failed clutch/brake seal problems will prevent oil from reaching the front pump.
When in there splurge about 15-$20 on a front pump de-stroker. This will ease cold weather starts.

muchtooffer48 · Mar 22, 2015

I always use the process of elimination to find a solution to problems..... IF, I can understand how something works! This jd500 backhoe seems to be a very complicated machine. But thankss to you guys I think I can fix it. Thank you again. Frank.

beenthere · Mar 22, 2015

muchtooffer48 said:
HELP HELP..... I have a JD500 series backhoe, I'm thinking about a 68-70 model, not really sure. It is a two stick, and I think it has two six volt batteries, not one twelve volt battery. Anyway, I bought this machine several years ago from the owner who had the pump rebuilt, and then sold it to me when the rebuilder refused to honor the warranty on the pump, and fix it right. This pumps leaks when the machine is running. I can not remember where I saw it leak but I'm guessing it is out the pump shaft, but I can't be sure. Maybe the builder of that pump didn't get the seals installed right, or damaged them when they were installed? Maybe these pumps have a history of this same problem that someone knows about. Can anyone direct me of the best way to go from here. Thank you very much. Frank. Hickory, n.c.

How about letting us know the model number, not just "JD500 series" ?? Will help with providing assistance, I'm thinking. What model do you have in that series?

Tx Jim · Mar 23, 2015

buickanddeere said:
Mother Deere put that drain line there for a reason. Everyone of those pumps weep some amount of oil past the seal.

Stating all JD hyd pumps leak is a broad statement. You must be referring to your beloved Dubuque/Mannheim hyd pumps leaking.

3010/4010/5010's's came from factory without a drain line and not all pumps leaked especially when brand new. True quad ring on shaft can let some oil by especially when shaft end play gets to great. JD engineers added drain line on latter models so that small amount of leakage could be put back in reservoir instead of on the ground.

FYI: buickanddear I was in attendance in Dallas in 1960 at the introduction of the JD New Generation tractors(3010/4010) that BTW had no frt pump seal drain lines installed and saw no hyd oil leaking from the tractors on the stage or concrete floor.

Tx Jim · Mar 23, 2015

beenthere said:
How about letting us know the model number, not just "JD500 series" ?? Will help with providing assistance, I'm thinking. What model do you have in that series?

Frt hyd pump on 500 series is basically the same from start to end of series.

MORRISONSTEEL · Mar 23, 2015

The 500 which was just a tractor only (backhoe was an att) was made from 63-67, the 500a was only made from 67-68, 500b from 69-71. An easy way to tell what vintage you may have could be what style of backhoe swing you have. If it is still the old style vane type swing then it is probably a 500 or 500a. If it has an actuall swing cylinder then a
500b or maybe even a 510 (71-83). Regardless, it doesn't really matter as mentioned these pumps where pretty much the same as far as the theory in which they operated. The size however did change. On the 500 it was just a 2.4 cu" pump (similar to 3010, 4010 and numerous utility tractors from 20-55 series), On the A and 510 it was a 3 cu" pump (similar to 3020, 4020, etc, etc) . 510b went to a 4 cu" pump. If you are having this work done I would recomend having a reman exchange priced out vs repair as it can be relativly expensinve to rebuild if you need much more than soft parts.

buickanddeere · Mar 23, 2015

Tx Jim said:
Stating all JD hyd pumps leak is a broad statement. You must be referring to your beloved Dubuque/Mannheim hyd pumps leaking.

3010/4010/5010's's came from factory without a drain line and not all pumps leaked especially when brand new. True quad ring on shaft can let some oil by especially when shaft end play gets to great. JD engineers added drain line on latter models so that small amount of leakage could be put back in reservoir instead of on the ground.

FYI: buickanddear I was in attendance in Dallas in 1960 at the introduction of the JD New Generation tractors(3010/4010) that BTW had no frt pump seal drain lines installed and saw no hyd oil leaking from the tractors on the stage or concrete floor.

The tractors were new, I hope they did not leak.
I already listed the Waterloo tractors with the little 1000 series pump and Dubuque/Mannheim tractors with the larger 2000 series pumps.

muchtooffer48 · Mar 23, 2015

MORRISONSTEEL said:
The 500 which was just a tractor only (backhoe was an att) was made from 63-67, the 500a was only made from 67-68, 500b from 69-71. An easy way to tell what vintage you may have could be what style of backhoe swing you have. If it is still the old style vane type swing then it is probably a 500 or 500a. If it has an actuall swing cylinder then a
500b or maybe even a 510 (71-83). Regardless, it doesn't really matter as mentioned these pumps where pretty much the same as far as the theory in which they operated. The size however did change. On the 500 it was just a 2.4 cu" pump (similar to 3010, 4010 and numerous utility tractors from 20-55 series), On the A and 510 it was a 3 cu" pump (similar to 3020, 4020, etc, etc) . 510b went to a 4 cu" pump. If you are having this work done I would recomend having a reman exchange priced out vs repair as it can be relativly expensinve to rebuild if you need much more than soft parts.

THANK THANK YOU! It has swing cylinders like the ford 555 does. So since it has jd500 I guess this makes it NOT a 510.
I found what looked like a ''B'' and the end of the word ''SERIES''. It first looked like a ''D''. But it is ''B''. Also, the only number I could find was on a tag, left side of the machine on the 6'' channel iron frame and it was B153P 151032R. ( I did find the engine number on a tag ) If this is the ''B'' model do I need to ask for the ''B'' manual? Or are they one in the same? Thanks again. Frank.