# 49 8n hydraulics



## oo7 (Jul 18, 2021)

I have recently noticed a heavy knocking when lifting the three point. I had my pump out, and was told it may not be lined up properly. Has anyone had similar trouble? Have I done any damage using it like this? I haven't tried lining it up


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## HarveyW (Sep 15, 2014)

According to John Smith, Ford Tractor Guru, the knocking is "normal" due to wear of the cam in the pump. Here is what he said...

"Unless your hydraulic pump is brand new or newly rebuilt, it will have some normal wear in the bronze cam that actuates the pistons in the pump. With 2 opposed pistons under high pressure and a cam rotating between them, you get a knock from the looseness (wear) on the cam. The knocking under heavy load is so common you can just about consider it normal. It will knock for a lot of years before it becomes so bad the piston doesn't get full stroke and you find the lift working very slow and knocking loudly all the time. Then you need a rebuild."


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## oo7 (Jul 18, 2021)

HarveyW said:


> According to John Smith, Ford Tractor Guru, the knocking is "normal" due to wear of the cam in the pump. Here is what he said...
> 
> "Unless your hydraulic pump is brand new or newly rebuilt, it will have some normal wear in the bronze cam that actuates the pistons in the pump. With 2 opposed pistons under high pressure and a cam rotating between them, you get a knock from the looseness (wear) on the cam. The knocking under heavy load is so common you can just about consider it normal. It will knock for a lot of years before it becomes so bad the piston doesn't get full stroke and you find the lift working very slow and knocking loudly all the time. Then you need a rebuild."





oo7 said:


> I have recently noticed a heavy knocking when lifting the three point. I had my pump out, and was told it may not be lined up properly. Has anyone had similar trouble? Have I done any damage using it like this? I haven't tried lining it up





HarveyW said:


> According to John Smith, Ford Tractor Guru, the knocking is "normal" due to wear of the cam in the pump. Here is what he said...
> 
> "Unless your hydraulic pump is brand new or newly rebuilt, it will have some normal wear in the bronze cam that actuates the pistons in the pump. With 2 opposed pistons under high pressure and a cam rotating between them, you get a knock from the looseness (wear) on the cam. The knocking under heavy load is so common you can just about consider it normal. It will knock for a lot of years before it becomes so bad the piston doesn't get full stroke and you find the lift working very slow and knocking loudly all the time. Then you need a rebuild."


Thanks much for the reply, now I wont worry


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