Hymac Swing brake

[strontium90]

Hello everyone...while I realise both my machine (a Hymac 580 C, a Hy Hoe based machine) and myself are about 40 years out of date for this forum, I will ask my question anyways...I have noticed the swing brake doesn't seem to be holding, making her sloppy to load trailers with...I suspect it could be either the springs in the control valve, the cross relief valve or the slew motor...I only bought her cheap, a week ago, to do a bit of cleaning up ditches round the farm..I would be grateful for anyone with some advice...thanks in advance.

Here are a couple of pics of the old girl to cheer you all up

 

[d4c24a]

get on to here https://www.facebook.com/groups/306795136154403/

 

[Tones]

Some of those machines when new had usless brakes. We just learnt to work around it and wasn;t much different to operating a crane or dragline.

 

[tctractors]

I might have this all wrong but the Hymac has a Staffa Motor on the swing that has the swing gear on the end of it's drive shaft, no brake plates in them if I recall, look up Staffa Motors I recall they are now owned by Kawasaki Pumps.
tctractors

 

[strontium90]

thanks

Thanks guys..I think it could be the control/spool valve..might be spring or o ring gone..Will try 1st

 

[lantraxco]

I might have this all wrong but the Hymac has a Staffa Motor on the swing that has the swing gear on the end of it's drive shaft, no brake plates in them if I recall, look up Staffa Motors I recall they are now owned by Kawasaki Pumps.
tctractors

TC, is that the Staffa radial piston, looks a bit like a starfish? Lovely motors in my experience (years ago)

 

[strontium90]

Yes guys...the slew pump looks exactly like the staffa one in google images...so there's no slew brake...I'm thinking it could be the spool valve which should be easy to remedy, as I can take the innards out of the aux one, as I don't have a rock hammer, and swap them with the slew spool...or maybe the cross relief...will maybe get a look at weekend...thanks for your help guys..

 

[Tones]

Yes guys...the slew pump looks exactly like the staffa one in google images...so there's no slew brake...I'm thinking it could be the spool valve which should be easy to remedy, as I can take the innards out of the aux one, as I don't have a rock hammer, and swap them with the slew spool...or maybe the cross relief...will maybe get a look at weekend...thanks for your help guys..

Mate, you could try to rejig it for no end result. Beleive me it's far easier on the pocket to learn to operate it the way it is and bear in mind it is more than likely it was like it from new. The MF 450S used the same motor on the slew and track drive but had drum brakes on the nondrive end and peddles on the floor to operate them. They didn't work either

 

[lantraxco]

By rights there should be a counterbalance valve somewhere, with a pair of reliefs handling the braking. Maybe not, but there should be.

 

[Vetech63]

Possibly worn seals on the Staffa motor Pistons.

 

[strontium90]

Thanks for the answers guys..I am going to live with it for the moment as want to get some work done...plus I'm getting used to it...Had bigger problems today anyways...she threw a track (probably a branch or stone) and it was half days work for a novice like me, to get it on...crowbars, fence posts, ropes and chains....and brute force...exhausted