BX2660 - Bypass valve whine when hot

[mjribeiro]

Wow - I'm clearly in the presence of some experienced trouble shooters. Thanks for all of the ideas guys!

I will try the feathering. Another scenario which may help or may be not is when I don't have the FEL mounted. When the oil is cold, hitting my FEL lever without the FEL mounted produces no noise. Once the oil is hot, hitting the lever in any direction produces the same loud, straining squeal as in the other scenarios. Bottoming or topping out the 3PT when hot does the same, but also not when cold.

I'm going to cut the lawn tonight and try to get the tractor to the dealer. If they have it too long I won't be able to cut the lawn.....

 

[oldnslo]

Wow - I'm clearly in the presence of some experienced trouble shooters. Thanks for all of the ideas guys!

I will try the feathering. Another scenario which may help or may be not is when I don't have the FEL mounted. When the oil is cold, hitting my FEL lever without the FEL mounted produces no noise. Once the oil is hot, hitting the lever in any direction produces the same loud, straining squeal as in the other scenarios. Bottoming or topping out the 3PT when hot does the same, but also not when cold.

I'm going to cut the lawn tonight and try to get the tractor to the dealer. If they have it too long I won't be able to cut the lawn.....

MJ,
Even without the FEL mounted you can try the feathering technique. You should hear the engine grunt a little as the pressure builds and then when you hit system relief the noise may start. Do you have access to pressure a gauge that you could put on one of the QD's from your FEL. If you do watch the pressure rise as you feather the valve and see if the noise repeats. From what you describing it sounds like the system relief gets noisier with warm oil which is not uncommon. The biggest concern is why would it be noisy when operating the FEL under what should be a no-load unless you feathering it without even realizing it.

Roy

 

[EE_Bota]

EE,
I think we are all trying to help and this one is very confusing. As you stated noise is typically associated to trying to do work. I have the BX1850 but have not looked at how it is plumbed. I think the FEL feeds oil to the 3PH but not sure. When using the FEL the one constant is the Priority flow control but that again is in the system all the time. Charge pump relief same thing, should be in the system all the time. My BX is all hard plumbed so....Really grasping for straws but could there be some mechanical line vibration under certain conditions that is causing this.

Roy, I know you are correct for my tractor (BX2200) and I believe you are correct for all BXs. So, the same hard lines that feed the loader valve on the newer ones conduct the oil to the lift. The oil goes out the gear pump, through the pressure line, through the loader valve's open centers, back out the power beyond port into the lift controls. So, you have indeed found a commonality to all functions that can make noise...the hard piping.

After your post, but before this one, the OP has said that the 3-pt lift makes the noise when at top when hot, but not cold. I would expect it to bypass either time.

He says it does the same with lowering the 3-pt...I would expect no noise whatsoever, hot or cold with lowering a 3-pt.

Maybe his oil is "noisy" due to air entrainment caused by a leaky inlet to the gear pump.

 

[mjribeiro]

I have an automotive brake line pressure gauge set, but I'd need to do some work to adapt it for the QDs. I will try the feathering with and without the FEL tonight.

 

[mjribeiro]

The feathering test didn't show any difference. It makes the noise feathered and at full open. I dropped it off at the dealer today.

 

[EE_Bota]

The feathering test didn't show any difference. It makes the noise feathered and at full open. I dropped it off at the dealer today.

I'm looking forward to the answer for sure. It doesn't sound like there is much wrong, so that is in your favor.

 

[SammyKY]

My new BX2660 does the same thing. No whine when cold, only when hot.

What did the dealer say?

 

[ClendenninTrail]

What ever it's worth, my BX25, new in December 2010, does the same thing when hot. When I told the dealer about it, he told me to bring the RPMs up to 3200 and to make sure I'm not feathering the hydraulics. His advice appeared to work. Once the tractor gets hot, I just keep it at 3200 rpms and if I don't want to hear noises, I make sure to not feather the hydraulics.

 

[mjribeiro]

So far dealer is saying its normal. It didn't do it when new, only now that there is 30 hrs on it (Still new in my book). They are running pressure tests today.

RPMS and feathering/full throw does not have any impact on mine.

 

[mjribeiro]

Dealer has now reproduced the noise and has reached out to warranty group for help. Looks like they will be placing either the 3pt valve or the FEL valve. Grass is 8 days tall now and I have no tractor........