Manitou heavy steering

[Drillman]

Manitou 627 and steering has gone heavy, any suggestions.

And no it’s not getting replaced with yellow, green or any other colour

cheers

 

[Thick Farmer]

I’ve got the same problem with a 628 pivot steer. Strangely, if I steer whilst lifting the boom, the steering is ok.

 

[Pan mixer]

@ACEngineering

 

[ACEngineering]

Manitou 627 and steering has gone heavy, any suggestions.

And no it’s not getting replaced with yellow, green or any other colour

cheers

almost certain to the the pump & steering priority valve. that's the best place to start anyway.

2 types of pumps, single or double depending on age and serial number.

 

[ACEngineering]

I’ve got the same problem with a 628 pivot steer. Strangely, if I steer whilst lifting the boom, the steering is ok.

is that the standard 628 or the 120hp LS one?

if standard one then again most likely steering priority valve attached to the pump, you can buy them sperately but IMO its best to buy the whole pump/valve assembly.
The pivot steers also suffer badly from crap designed steering rams, the pistons inside the ram only have the oil seal on them, they dont have any baring rings to support the piston in the bore and stop the piston scoring the bore. These can be modified at a ram shop to take a different piston and 1 baring ring which is better than nothing but ideally 2 would be best but theirs just no room to fit 2. Both rams must be done at the same time and both MUST be identical travel.

 

[Thick Farmer]

is that the standard 628 or the 120hp LS one?

if standard one then again most likely steering priority valve attached to the pump, you can buy them sperately but IMO its best to buy the whole pump/valve assembly.
The pivot steers also suffer badly from crap designed steering rams, the pistons inside the ram only have the oil seal on them, they dont have any baring rings to support the piston in the bore and stop the piston scoring the bore. These can be modified at a ram shop to take a different piston and 1 baring ring which is better than nothing but ideally 2 would be best but theirs just no room to fit 2. Both rams must be done at the same time and both MUST be identical travel.

It’s the 120 LSU I think. 08 plate.

 

[ACEngineering]

It’s the 120 LSU I think. 08 plate.

If it is the 120hp then Need to start with the steering rams, even if there not the current problem they will at some point score the cylinders if not modified and bearings sorted if needed. Often when they score the cylinders they fill/block the steering orbital unit up with metal fillings and normally results in a new orbital unit as well. Plus a tank clean and filters etc.

You could also remove the spool for them the inlet section of the main spool block and check for scoring and clean it with scotch brite pad and oil. (thats were the steering priority valve is on the 120hp MLA)

 

[Thick Farmer]

If it is the 120hp then Need to start with the steering rams, even if there not the current problem they will at some point score the cylinders if not modified and bearings sorted if needed. Often when they score the cylinders they fill/block the steering orbital unit up with metal fillings and normally results in a new orbital unit as well. Plus a tank clean and filters etc.

You could also remove the spool for them the inlet section of the main spool block and check for scoring and clean it with scotch brite pad and oil. (thats were the steering priority valve is on the 120hp MLA)

Thanks. I’ve got a few of these so first step is to swap the rams and then move onto the rest I suppose.

 

[Drillman]

almost certain to the the pump & steering priority valve. that's the best place to start anyway.

2 types of pumps, single or double depending on age and serial number.

Just thinking mine is the 4ws version not the bend in the middle type I assume it’s still the same issue?

 

[ACEngineering]

Just thinking mine is the 4ws version not the bend in the middle type I assume it’s still the same issue?

Yes I was assuming yours was 4ws. There is a pivot 627 but it's very old now not very many around.

 

[ACEngineering]

Thanks. I’ve got a few of these so first step is to swap the rams and then move onto the rest I suppose.

Just open the rams up and make them better. Once you look at the piston and compare to ANY other hydraulic ram piston you will understand just how crap it is. Why people cant see the obvious when they design these machines I dont know!