Puma 155 suspension problems

[Dirt surfer]

Can anyone give me some advise on rock hard front suspension please.
I’ve had the tractor from new and suspension has never seemed to have worked.
I put a new accumulator on a few years back but that didn't seem to make any difference.
I’ve had dealer look at it to no avail, they thought it was working. My arse it is.
I’d very grateful for any useful pointers.
Cheers.

 

[del_boy]

Its usually the accumulators and they dont last long. We've replaced a few around the 3k hours mark.
Does it calibrate ok?
You can undo the little grub screw on the accumulator just slightly to see if you can hear any gas come out, an indicator if the accumulator is goosed or not.
Also on the nh versions the earlier ones used to rub the front suspension wire through on the radiator cowling so check that.
Could be the lock out valve stuck.
If it calibrates ok and the accumulator is ok its probably working but it is crap.
@Colliedog is able to supply you with both a cab and front suspension upgrade

 

[davidroberts30]

@Colliedog is the man ?

 

[Colliedog]

If you’re dealer said it was working it probably is. If you put a cable tie around the ram and push it up against the seal you then drive it around you will be able to see how much travel you have. The good news is it can be made to work very well quite easily. Have a read of this post. https://thefarmingforum.co.uk/index...ulator-pressures-for-the-perfect-ride.313622/

 

[ColinV6]

I put 600kg on the front links, the difference is pretty impressive. Like yours it never seemed to do much before that.

 

[davidroberts30]

Or just lower the pressure in the accumulators..

 

[Colliedog]

Think of it as a good suspension system With a spring that’s too small to cope.
The spring is the gas compressed in the accumulator.
Fit a bigger spring, which is more gas in larger accumulator volumes and it works very well.
Carrying a weight helps as it forces oil though the pressure relief valve faster but upgrading the accumulators is the best option.

 

[Dirt surfer]

Think of it as a good suspension system With a spring that’s too small to cope.
The spring is the gas compressed in the accumulator.
Fit a bigger spring, which is more gas in larger accumulator volumes and it works very well.
Carrying a weight helps as it forces oil though the pressure relief valve faster but upgrading the accumulators is the best option.

Thanks for all your help I have now established that the accumulator is shot as oil comes out of the valve on the end when loosened. My tractor is a 2011 puma 155 so has the same wheelbase as a T6 NH. I have replaced an accumulator a few years back as it was shot but didn’t notice much difference after that so just put up with it as dealer couldn’t shine any light on it.
I can’t find anything in ops book on how to calibrate the suspension so will have to talk to dealer.
However when parked up it sinks down a bit then on starting and moving it levels up again so I’m guessing it’s working but just needs a new accumulator with the correct pressure in it?? And maybe a bigger one.
I would just like to get it to give a decent ride when towing a trailer empty and loaded.
Looking at your axle loads and system pressures I would guess 30 bar should be about right?
I would be grateful for your thoughts.
Thanks again.

 

[del_boy]

Yeah you wont be far off at 30 bar. If you go to a bigger accumulator you might need to re route it and fix it on the rear axle, i done a nh t7200 like this.
Pretty sure you'll need the diagnostic plug to access the h menus if its the same as nh to calibrate the front suspension.
It wont be ideal to get a nice ride with both a loaded and empty trailer as the front axle weights will change too much. Best bet is to fit an extra accumulator, and set them at different pressures, you wont be disappointed

 

[Colliedog]

Thanks for all your help I have now established that the accumulator is shot as oil comes out of the valve on the end when loosened. My tractor is a 2011 puma 155 so has the same wheelbase as a T6 NH. I have replaced an accumulator a few years back as it was shot but didn’t notice much difference after that so just put up with it as dealer couldn’t shine any light on it.
I can’t find anything in ops book on how to calibrate the suspension so will have to talk to dealer.
However when parked up it sinks down a bit then on starting and moving it levels up again so I’m guessing it’s working but just needs a new accumulator with the correct pressure in it?? And maybe a bigger one.
I would just like to get it to give a decent ride when towing a trailer empty and loaded.
Looking at your axle loads and system pressures I would guess 30 bar should be about right?
I would be grateful for your thoughts.
Thanks again.

Yes that’s the idea. I have tested a 30bar 2ltr accumulator straight in the valve block as seen in this picture. The performance was a fair way towards how my final kit I have developed is performing. The only thing was because of its size it looked a bit vulnerable mounted directly on the valve chest if your wheels were to pack up with mud. 1&2 ltr accumulators should be compatible parts for my kits if you wanted to upgrade to one at a later date.