Jump to content

Garden Tractors and Parts on eBay



Photo
- - - - -

Resetting loader relief valve?


  • Please log in to reply
25 replies to this topic

#16 zuren OFFLINE  

zuren
  • Senior Member
  • Member No: 65629
  • 211 Thanks
  • 209 posts
  • Location: SE Michigan

Posted September 02, 2020 - 01:32 PM

Hi Chris as Glenn posted the High R's should be much hiher at least 3400 and yes my tractors have that limiter but they are set up as you noted the pressure is set at 3300 R's you'll find it easy to adjust the PSI at those RPM's. By the way idle r's for the K361 is 1700

Nice gauge set up I have a gauge that looks like it but have never gotten busy and connected a hose and fittings to it maybe after my front wt mount build

 

1700 RPM is supposed to be idle for the K361?!?!?  I think mine was 800 RPMs!!!  I have no idea why it has been set like this.  


  • MNGB said thank you

#17 MNGB ONLINE  

MNGB
  • Senior Member
  • Contributor
  • Member No: 62466
  • 4979 Thanks
  • 2482 posts
  • Location: Minnesota

Posted September 02, 2020 - 08:01 PM

Yes Chris you need to set the RPM's up for idle to 1700 they had a memo to set it there I'm thinking for better cooling and oiling of the overhead its the first page of the K361 owners manual from PK



#18 zuren OFFLINE  

zuren
  • Senior Member
  • Member No: 65629
  • 211 Thanks
  • 209 posts
  • Location: SE Michigan

Posted September 08, 2020 - 09:58 AM

Just a quick update...

 

I had a side conversation with MNGB.  Seems that the wireless tachometer I am using may not be accurate, so I have a better no-contact tachometer coming.  Once I can get an accurate reading, I'll be able to determine if the pressure relief valve (PRV) is having a problem.

 

So, assuming that I set the engine to the correct RPMs and I cannot get the PSI to rise, is it reasonable to believe that the spring in the PRV is tired/weak?  I have a quote for new parts from QCC.  


  • Cvans and MNGB have said thanks

#19 Cvans OFFLINE  

Cvans
  • Senior Member
  • -GTt Supporter-
  • Member No: 5412
  • 9315 Thanks
  • 7202 posts
  • Location: East central SD.

Posted September 08, 2020 - 10:16 AM

is it reasonable to believe that the spring in the PRV is tired/weak?  

 

It's possible but it could be broken or the plunger stuck as well. More likely is the pump is worn. Is there a filter screen in the system? Also a collapsed hose can be the issue especially on the intake side of the pump. The outside of the hose can look fine but the inside can be restricted. 


  • MNGB said thank you

#20 zuren OFFLINE  

zuren
  • Senior Member
  • Member No: 65629
  • 211 Thanks
  • 209 posts
  • Location: SE Michigan

Posted September 10, 2020 - 08:07 PM

Another quick update...

 

I now have a no-contact tachometer and was able to make an accurate measurement of the engine RPMs:


Idle = 1800-1850 RPMs

WOT = 3450-3500 RPMs

 

As for the hydraulic pressure at WOT, I'm still below 1000 PSI.

 

It's possible but it could be broken or the plunger stuck as well. More likely is the pump is worn. Is there a filter screen in the system? Also a collapsed hose can be the issue especially on the intake side of the pump. The outside of the hose can look fine but the inside can be restricted. 

 

I have a filter on the return line, but there is no filter screen in this system.  Hoses are all new 3000 PSI hydraulic lines.  Now, I did change the feedline from the tank to the pump to a 3/4" hose rather than 3/8".  I don't see how that would cause low pressure on the output side, but that is a change I made with this loader project.

 

The other thing I have not done is test a different port off of the control valve. 

 

When I hit the limits and the pressure relief opens, I'm hearing the squeal at the control valve...I think.  If the pump were worn and allowing bypass, wouldn't I be hearing something there?  I have a stethoscope for finding bad bearings, so I may see if that can help me figure out the definitive location of the pressure relief squeal.

 

I can try to swap out the pressure relief parts - QCC quoted me $50.  This loader project has already cost me a bit of cash...what's another $50?!?!  The existing parts are 43 years old so new couldn't hurt.  Then if my PSI is still low, the pump is the only thing left.  

The good thing is that everything works, and I'm slowly eliminating any leaks.

 

Thanks! 


Edited by zuren, September 10, 2020 - 08:08 PM.

  • Cvans and MNGB have said thanks

#21 MNGB ONLINE  

MNGB
  • Senior Member
  • Contributor
  • Member No: 62466
  • 4979 Thanks
  • 2482 posts
  • Location: Minnesota

Posted September 10, 2020 - 09:06 PM

Hi Chris good to hear the new Tach is working I  guess with a 1000 PSI I wouldn't to worried that will lift as much as the tractor can handle and yea the R's are good is the 3450-3500 where the limiter was?



#22 Cvans OFFLINE  

Cvans
  • Senior Member
  • -GTt Supporter-
  • Member No: 5412
  • 9315 Thanks
  • 7202 posts
  • Location: East central SD.

Posted September 10, 2020 - 11:08 PM

I would have to agree with you in that if the pump is able to generate enough pressure to open the relief valve it's probably OK. I can't remember if you said at what pressure the relief valve was opening. 


  • MNGB said thank you

#23 zuren OFFLINE  

zuren
  • Senior Member
  • Member No: 65629
  • 211 Thanks
  • 209 posts
  • Location: SE Michigan

Posted September 11, 2020 - 06:12 AM

I would have to agree with you in that if the pump is able to generate enough pressure to open the relief valve it's probably OK. I can't remember if you said at what pressure the relief valve was opening. 

 

It is opening somewhere above 750 PSI but below 1000 PSI.  The needle is not stable.

 

 

Hi Chris good to hear the new Tach is working I  guess with a 1000 PSI I wouldn't to worried that will lift as much as the tractor can handle and yea the R's are good is the 3450-3500 where the limiter was?

 

It must have been.  I tried going up to the 3600 RPM spec but 3450-3500 just sounded smoother and what I remembered...if that makes sense.  I figured 100-150 RPM less wouldn't hurt anything.   


Edited by zuren, September 11, 2020 - 06:42 AM.

  • Cvans and MNGB have said thanks

#24 zuren OFFLINE  

zuren
  • Senior Member
  • Member No: 65629
  • 211 Thanks
  • 209 posts
  • Location: SE Michigan

Posted September 12, 2020 - 09:26 AM

Update: 12SEP2020...

 

I have full, stable pressure!  The sound that I was hearing...that I thought was the relief valve?  It was the belt slipping under load.  It did not sound like a slipping belt...at all.  I got out my mechanic's stethoscope and started touching parts of the hydraulic system while creating the sound and it was at the pump.  I was too focused on watching the pressure, and had already tensioned the belt (2x), so I had the hood down and didn't see the slipping.  

 

I have been fighting with this belt for a while to keep it tensioned.  Hopefully I have that solved now.  I now have the pressure relief dialed in to 1250 PSI at the loader controller, and the pressure relief at the rear controller (should be at 1000 PSI) is working as it should.  I will have to keep a better eye on that belt tension.  

 


  • KennyP and MNGB have said thanks

#25 MNGB ONLINE  

MNGB
  • Senior Member
  • Contributor
  • Member No: 62466
  • 4979 Thanks
  • 2482 posts
  • Location: Minnesota

Posted September 12, 2020 - 04:09 PM

Hi Chris, that's good to hear I bet there is a big smile now,  did it make any noticeable difference in how the loader and 3 pt go up & down. Does your belt tensioner rod have the spring on it to keep pressure on the belt when it wears \? 



#26 Cvans OFFLINE  

Cvans
  • Senior Member
  • -GTt Supporter-
  • Member No: 5412
  • 9315 Thanks
  • 7202 posts
  • Location: East central SD.

Posted September 12, 2020 - 10:28 PM

Do you have a raw rubber edged belt on there or a woven belt? A rubber edged belt will carry more of a load. 


  • MNGB said thank you




Top