I have a BPA 500 and was wondering if any body knows how the hydraulic system could cause the motor to over heat? This is assuming the motor is in good working condition.

if it is a rock valve some times the change over ram leaks internally that is not visible .how to find out is when it is in pump stand by the back of the hopper you should hear hissing which is the oil seeping past the seal. this has been known to cause over heating.but its been over 12 year since I last to a schwing out

if the engine is in good working condition, why is it overheating? check cooling system, cooling fan etc., I dont know if yours is air or water cooled, if air cooled make sure fan is running and all covers are in place; if there is a problem within the hyd. system, it would heat up the hyd. oil and not the engine

I thought the same thing about the hydraulic oil getting hot but it doesn't . The engine guys tell me that some times the hydraulic pump can over pressure and put drag on the motor causing it to over heat. It is a air/oil cooled deutez motor. I'm just looking for ideas. Keep them coming.

the hyd pump on your pump has a setting called horsepower control, which means, that if you increase pressure the hyd. pump cuts back on the hyd. oil flow to prevent the engine from stalling out; but still it does not overheat the engine; so yes it does put a drag on the engine, but this is designed that way, you may want to get a second opinion...

Maybe the termostat is stuck in one possition? But I guess thats one of the first things you've already checked...

The thermostat has been replaced and they also checked the timing. At this point I have to exhaust all off my options on the hydraulic side before I take the machine back to them. I do have confidence in the guys that rebuilt this motor. Long story but the short version. The motor is on its third rebuild. The first company that rebuilt it twice never could get the thing put together right. Timing issues,loose head bolts, missing pieces,and so on. This company I used this time rebuilds Duetz motors and thats all they deal with. By the way, I know what your thinking. I tried to go with the lowest bidder on the first company. I did not. I went in to this wanting my motor fixed and back up and running. They seemed to have a good reputation. Anyway, I need ideas on the hydraulic side.

This would make the hydraulic oil get hot wouldn't it? The oil stays around 150 degrees while its pumping. When I'm pumping like the other day. 200' feet of system and good mud , 5" slump. The motor drops RPM's when the cylinders are pushing. Probably 300 RPM's . But their will be a good stream coming out the end of the hose. What about the pressure bypass switches? Could they be hung open causing the pump to over pressure?

check your pressure settings, pressure relief for hyd. pump si 268bar; main relief 275bar; check soft switch pressure, should be 100 bar; if you were to adjust the main relief below the pressure relief for the pump the engine is bogging down noticable, but not to a point where it stalls the engine;this will also put a load on the engine, and you can see if it is heats up out of the normal; count your strokes per minute, engine at 2200rpm, stroke limiter all the way open, no pressure applied to the concrete pump (pref. run pump in reverse); theoretical is 34 strokes per min, if you achive 32 with a used pump you should be ok.

if you have any other readings than above, you probably have something going on, that needs to be worked on, but those are easy checks you can yourself; if this is all good, get yourself an infrared thermometer and run the pump and find hot spots, that is a good tool to find potential problems in the system

150 degres Fahrenheit? if that is the case then you are within operating temp. (that 's 65deg. C) I would not want to see it much higher though,

Now we are getting somewhere. Thank you for your advise. Not Celsius. I will try next chance I get.

How do you know what temperature its running at? If air cooled, does it have a gauge? I would think it should be running between 160 and 190 degrees F.

How is your fuel economy? Is your turbo alright? Just a thought.

   On the temparture, we used a handheld aim point chingaleda. I don't know what you call them but it reads temp when you point it at it. Just pumping water, it read upwards of 190+. The turbo was getting  I think around 600-700. Fuel economy seems to be normal. I didn't run it long enough to see oil consumption.  It didn't smoke.They said the turbo didn't have any play in it and the fins spun freely and easy. I did and still question that  just because of the discoloring of the exhaust side of it and exhaust manifold.

Yeah 190 is as high as you want. Interesting ? How about air leaks on the manifold. Extra air is like blowing on a fire.

I was told that you have to run those 500's wide open, because you put to much strain on the turbo, which could cause some high heat situations. But that is just a word through the grape vine. Never actually ran one.

You are sorta right. The motor is set to a certain rpm for proper operating pressure. You can over heat one if you run it to low. Mine is set at 2600 rpm. If i want to pump slower I use the pressure control valve and slow it down . Other wise I run that wide open or I feather it to control hose movement. The crews appreciate it.

Have you checked the oil cooler?

Bad injector running lean also.