8550 hydraulic noise/vibration
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Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=143317
Printed Date: 18 Aug 2025 at 9:55am
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Topic: 8550 hydraulic noise/vibration
Posted By: grinder220
Subject: 8550 hydraulic noise/vibration
Date Posted: 10 Oct 2017 at 8:47pm
| The pump on the rear end has made a load whine/groan noise as long as I've owned it (10 years),sounds like its running out of oil. Its not constant,it comes and goes all on its own. When it does this the big line that goes to the spool valves and PTO valve will vibrate rapidly. It has no effect on hydraulic functions. Any ideas? |
Replies:
Posted By: MACK
Date Posted: 10 Oct 2017 at 8:56pm
| Most likely a hydraulic line touching metal somewhere. MACK |
Posted By: grinder220
Date Posted: 10 Oct 2017 at 10:27pm
| No this is something internal and loud. All the lines are isolated. When a remote lever is pulled it makes a similar sound just not as loud. But like I said it's spuratic whether tractor is just sitting idling or out working. |
Posted By: grinder220
Date Posted: 12 Oct 2017 at 10:00am
| Bump |
Posted By: darrel in ND
Date Posted: 12 Oct 2017 at 8:41pm
| have you ever checked stand by pressure? Darrel |
Posted By: Kevin in WA
Date Posted: 12 Oct 2017 at 10:07pm
| Like Darrel said, check standby pressure, to make sure its not running in high pressure mode all the time, does it have 3 point? feedback linkage could be out of adjustment causing it to run in high pressure. |
Posted By: grinder220
Date Posted: 12 Oct 2017 at 10:18pm
| No I haven't checked pressure. Doesn't have a 3 point. If the pressure is high what needs to be done? |
Posted By: rustydollar
Date Posted: 12 Oct 2017 at 10:42pm
The reason your hydraulics work fine is because the first pump in your hydro unit is the charge pump. Charge pump has implement ports that supply hydraulic oil for the tractors accessories. I would suggest changing the filter, if it's obstructed in any way the charge pump will be short of a continuous oil supply. When I change a filter I always cut it open to examine the paper cartridge for foreign material. No metallic particles is always good news. |
grinder220 wrote:Posted By: DrAllis
Date Posted: 13 Oct 2017 at 7:14am
| Connect a 3000 psi gauge to the JIC tee with the cap on it on the side of the PTO valve. Remove the cap and connect the gauge. Pressure with engine running should be a steady 350 to 600 psi with hydraulics at rest. Pressure should be a steady 2500 psi when you activate and hold any remote lever. What do you have. |
Posted By: grinder220
Date Posted: 13 Oct 2017 at 12:34pm
| I'll check pressure this weekend. |