Bomag BW211D-3

[BobH52]

I'm new here so I'm not sure if this is the right area to post this.
We have a BW211D-3 that has very stiff steering and also sometimes won't travel in either direction. It will start forward a couple feet then stop, then it can go in reverse a few feet.
I checked the pressure at the steering pump and I have over 2000 psi at about half throttle.
My pressure on my travel pump goes to 3000 psi then drops to 0 in forward. In reverse it rises and falls in a similar fashion.
I did find a lot of bright metal flakes in my hydraulic filter that my local dealer said was probably from the steering system.
We just purchased this machine and I can't find a service manual for it so I don't know where to start looking for my pressure problem.

 

[mg2361]

Welcome to HEF Bob!

I will try and help. Not real familiar with that size Bomag. Others on this forum are pretty good with Bomag.
First, how about posting a serial number. That would be needed to get correct information.

 

[Vetech63]

I did find a lot of bright metal flakes in my hydraulic filter that my local dealer said was probably from the steering system

A pic of this would be fantastic!

I don't know where to start looking for my pressure problem.

Start with the charge pressure testing. We definitely need a complete serial number to have the proper locations and pressure ratings info.

I checked the pressure at the steering pump and I have over 2000 psi at about half throttle

All the pressures should be checked at full throttle with the hydraulic oil at operating temperature.

We just purchased this machine

From whom did you buy this from? auction? individual? equipment dealer?

 

[BobH52]

Guys, the serial number is 101580851562
I'll try to get a picture of metal debris.
I think it came from a dealer, It's really not mine, it belongs to a friend who I help out, I'm retired.

 

[mg2361]

Start with the charge pressure testing.

Ditto what he said. ^^^^

Steering and charge are both the same pump. Charge checked at full throttle, steering at idle (according to the manual), with oil at approximately 50*C (120*F). Charge pressure should be approximately 25 bar (360 psi) measured at the filter. Steering pressure spec is 190 +/- 10 bar (2755 +/- 140 psi) measured at the pump.

 

[BobH52]

So you are saying the steering pump charges the travel pump and the vibrator pump.

 

[BobH52]

Where can I get a download manual?

 

[BobH52]

Thanks guys. I have almost no pressure at the pump at idle and less than 100 psi at the filter at full throttle. The machine does sound like it is starving for fluid. So I suppose this is the bad pump?

 

[mg2361]

So you are saying the steering pump charges the travel pump and the vibrator pump.

Correct.

Where can I get a download manual?

Unless someone put it out there you can't. You would have to purchase one. I see it "on-line" through a dealer portal.

The machine does sound like it is starving for fluid.

Make sure there are no restrictions to the supply side of the steering pump.

How about a picture of the metal in the filter?

 

[Vetech63]

I have almost no pressure at the pump at idle and less than 100 psi at the filter at full throttle

Well, hopefully the main hydrostats haven't starved for long. My concern is that pump has contaminated the main pumps and destroyed your wear plates and rotating groups. Is the filter on the pressure side or the return side? I've seen it both ways. If its on the pressure side you may get lucky.
If you need a new charge pump, price one from Bomag and post that cost here. There is other options I have used that have been very successful and a lot cheaper.

 

[BobH52]

I'll check the filter and try to see the routing.
I did price a pump from Bomag, $850 or so.

 

[BobH52]

Do you have the link to the dealer portal so I can check on a manual.
The only ones I could find didn't have the complete hydraulic system and was lacking a lot of other details.

 

[Vetech63]

Do you have the link to the dealer portal so I can check on a manual

I do not have a link for you. I usually call tech support and have them email what I need but, I am also a repair contractor that has dealt with those people for a long time. I'm not sure what they would be willing to send out to others that contact them.
Could you post a pic of the filter assembly and any debris you have found? Is there any brass looking material in the filings?

 

[mg2361]

Is the filter on the pressure side or the return side?

Schematic shows filter on the outlet side ("T" port) of the steering valve, then the oil from the filter moves on to the piston pump charge circuits.

Do you have the link to the dealer portal so I can check on a manual.

Won't do you any good. You have to be an approved dealer for access.

 

[BobH52]

I was thinking the filter was on the outlet of the steering box but wasn't sure if it bypassed the filter before it went to the main pumps.
I did not see any brass in the filter so hopefully my mains are ok. I'm still concerned about my pressure relief valves being stuck.
I have a dealer near me that just started handling Bomag Jeffords Corp., and I know the parts and service people. So they will probably be able to get me the hydraulic diagrams.
I'll let you know what I find, and try to get some pictures of the debris.
Thanks.