So recently I’ve noticed a leak which is coming from the area of my hydraulic pump motor. It seems to be getting worse and the machine isn’t as powerful. The excavator is a 1987 Dresser 645. Pump is a hydromatik and the serial number is A2f63w2z2 I have searched all around for a new pump and finally believe I have found one from a company in china. Parts for this machine seem near impossible to find. Can anyone tell me anything about this pump or where I might find one in America? i have been able to break down the serial number which was helpful. Also can anyone tell me what the “20 degree” on the side Means? Thanks
Looks to be a bent axis hydraulic piston motor set up for your slew/swing drive. Not sure who would be able to supply these to you locally but you would probably get a repower to fit providing it had a common mount , **** and porting configuration. The number on the side of the hydraulic motor will most likely refer to the maximum incline of the piston group. There is a Korean manufacturer called "Handok" that sell aftermarket parts and complete units similar to these. If you need any further help in a cross over let me know and I will try and help you with sourcing a replacement.
Looks to be a bent axis hydraulic piston motor set up for your slew/swing drive. Not sure who would be able to supply these to you locally but you would probably get a repower to fit providing it had a common mount , **** and porting configuration. The number on the side of the hydraulic motor will most likely refer to the maximum incline of the piston group. There is a Korean manufacturer called "Handok" that sell aftermarket parts and complete units similar to these. If you need any further help in a cross over let me know and I will try and help you with sourcing a replacement.
Thanks for your reply, I was able to find this pump. Today I worked with the machine for an hour or so to try and locate leaks. I am not familiar with these pumps so forgive me for lack of knowledge on this, I wrapped the pump with tampons and put tape around the top of that contraption the pump is bolted on. It was fairly dry. The bottom piece was still oily. Also the relief valves to the left was leaking pretty good on the clean tampons. I’ll post a picture or video. [Hot Item] Hydraulic Motor A2f A2f63W2z2 A2f63W2p1 A2f63 A2f Series Axial Piston Fixed Motor High Speed Certification: GS, RoHS, CE, ISO9001 Excitation Mode: Excited Power Rating: 3000W Casing Protection: Closed Type Number of Poles: 8 Speed: Low Speed emanway.en.made-in-china.com
The forum won’t let me share videos
Right off, you can see the motor housing angle is sharper than what you have, even the body casting indicates 40° vs your existing 20°. You sure you don't have a flat anti-cav or tired relief valves? How about the brake, are you getting proper pressure to release? This is all based off your pics which show us a slew motor. Are all functions slow/weak? You may be looking at a bad or misadjusted main relief. Have you gauged pressure? Do you know what it should be?
I’m trying to figure out how to post some additional pictures and a video. But yes the machine operates and is functional but I believe it is slow and weak compared to what it should be. I’ll try and figure out these pictures and if not get better ones when I’m back where the machine is. I have not gaged pressure nor do I know what it should be. There is hydro leaking under the relieve as well. Not sure I understand the housing angle, the casting says 20 degrees on it? Sorry I’m a rookie over here
You have to host them on anoher site (e.g. Youtube) and then link them.
The easiest way to check any hydraulic motor is to measure the casedrain oil flow. To do this, remove the pipe from the motor and fit a hose which then the other end goes into a pail. With the hydraulic motor stalled rev the engine to WOT and activate the lever, hold it there for 1min. Deactivate the lever, shut the engine down and measure the amount of oil in the pail. About a pint or a little more would indicate the motor is OK, any more then its likely the internals are worn but maybe repairable. Scratched lens plate and slippers can fixed by lapping if they're not to badly damaged. Guessing failures is a mug's game so test everything from the pump for pressure and flow. This may involve hiring help but it's cheaper than fixing what ain't broke.
Good advice thank you. I would gladly hire help if I could find some
Maybe this link will work
video came thru fine...maybe that will help the diagnosis folks. I am a watcher/learner.
You have what appears to be a leaking out put shaft seal which indicates a worn motor. The way things are mounted there you have a hydraulic motor bolted to a planetary reduction gearbox and a pinion gear which engages with the swing circle. Check the oil level in the gearbox, if it's over full it will be with hydraulic oil and is further confirmation of a motor problem. That hydraulic motor going off the model numbers is 63cc bent axis, Rexroth make one but how similar they are I don't know. I came across them driving forestry mulchers.
I plugged that number into Kolben's website and got this. Product Page Might even be able to get a rebuild kit for that.
Yea I’m waiting on a quote from them. I’ll see what they come back with
Check the motor size. I reckon it's smaller than what you require.With model numbers after the type is the size. Your current one is 63. So 63cc versus 50 cc. This is rule of thumb.
Please explain the rule of thumb. What exactly should I be checking, there is almost no info out there on a dresser 645? I will never ever buy an old European machine that parts are impossible to get again
I think Tones was advising you to double check your hydraulic motors model code. the motor in the post from Kolben is actually a 500 cm3 pump not a 63 cm3 motor, which is what you have. Have a look at the pic attached which gives a similar internal view of your hydraulic motor. item 1 is a shaft seal which can possibly leak and item 2 is the shaft seal carrier which also has an oring that can leak oil. If you suspect the oil is leaking from the bottom of the hydraulic motor you could try removing and inspecting the bottom of the shaft and seals. The seal carrier is usually retained with a large internal circlip and the seal carrier may be under load so don't try to remove the circlip before removing the head cover at the other end. Looks like you may have a few oil leaks to fix on the old girl. Hope this helps
Bosch Rexroth Finally did my own search and found this. As I first thought it's a Rexroth bent axis motor and internals can be easily sourced. Brian if the casing isn't cracked it's more than likely can be rebuilt with new genuine parts.
I’m sorry I am just seeing this post now, I am going to take a look and report back. I did get some pics today.
View attachment IMG_1232.jpeg
More pics