Super dexta cylinder head and hydraulic issues

[Gavin]

Hi I am in the process of restoring a Super Dexta which i have wned now for about 20 years but has sadly spent the last 6 in the corner of the yard.
Prior to being parked up it was a very poor starter - first it would fire up on one cylinder then the other two would cut in but since standing the engine has seized completely. I purchased many years ago a replacement block as the original has the normal crack along one side and this has been fitted with new liners and the crank reground and is now being rebuilt. This week I removed the head from the original engine and found that 2 exhaust valves have virtually no seat left in the head which poses the question do I have the existing head overhauled or purchase a new Agriline head for about the same outlay. I have seen some issues with these replacements so what is the general opinion?

Secondly I seem to remember that the hydraulics were very slow to operate when first starting the engine and would sometimes take minutes before lifting but once operating they were fine. This tractor is fitted with a loader so has probably had a fair amount of demand on the hydraulic system. Any suggestions as to where i should look for the fault bearing in mind that at the moment I am unable to start the engine and i really need to get this machine operative asap since my 4610 is too big to get into a couple of our fields that I desperately need to top and fertilise.

[llanfair]

Hi Gavin
I think i would have the head skimmed, New valve inserts & guides fitted at a good machine shop. Better the devil you know than the one you don't.
Good Luck
JOHN

PS See Russelms post Mon Jul 5.

[Gavin]

Thanks John,
I had already seen that post and this is my concern regarding these heads. Yes they are £100 cheaper than the competition and look very appealing but could be more of a problem than they are worth. Will be interesting to see the outcome from Agriline on this issue.

[commander]

If you take the old head to a machinist, make sure they vacuum/pressure test it before returning it to you. These old heads can have cracks in the ports that are not easy to see.

The slow hydraulics: I would 1)clean the suction strainer and replace the o-ring on it. 2)Inspect & clean the discharge filter assembly and replace o-rings. 3)Pull the unloader valve from the valve chest , clean everything in there up and replace the o-ring (or just leave the o-ring off it). The o-ring fitted to this valve tends to swell over time and cause the valve to stick - when/while it's stuck - no lift.

Replace other o-rings in the lift cover while it's off.