2090 Pilot Spools

[AFL]

Having some trouble with the powershift on the 2090. Specifically the engine is under load in the first range and will stall when it"s shifted to reverse. 2 and 3 seem to be fine. It sounds like one of the spools in the powershift control valve is sticking. We found the one that seems to be causing the problem, but there doesn"t appear to be anything wrong with the spool. So can someone please give me the proper procedure to clean these things out? What type of solvent do you clean these with, brake cleaner, carb cleaner, gas? We removed the spool with a 10-24 screw as recommended on this site. The spool itself looks clean and there isn"t any varnish on anything. But when you place the spool in the assembly it starts hanging up right away. Any help appreciated, thanks guys.
 

[DKase]

I pull them out and polish them up really good with emery cloth. Make sure you clean them up good so the grit from the emery cloth is all cleaned off. I was told by an old Case shop foreman that if the emery cloth trick does not work to get a stainless ball the same size as the bore, weld a bolt onto it for a handle, heat it to just barely glowing red so it expands in size just a little and push it into the bore to expand the hole just a little. The emery cloth took care of mine so I have not had to try the ball trick.
 

[casetrader]

DK is correct but I do take all 4 out chuck in my cordless drill very fine emery an clean rag nothing in bore, let oil drain to clean, very seldom see the problem.
 

[mEl]

I try to avoid polishing the spool if I can.

Reason, the spool edges should be sharp to wipe impurities off when they move. Rounding the spool edges creates a situation where minute pieces of material can actually be forced into the surface of the aluninum body.

I always use the spool and the screw and lots of cleaner and just keep working it till it gets free. Abrasives of any kind are a last resort for me.

I am not for any method that increases the working clearances of the spool/ bore.

mEl
 

[1370rod]

I agree completely, abrasives are a no,no. The problem is those tiny steel flakes embeded in the aluminum valve body that scrores and sticks the pilot spool. They can be work out as mEl mentioned, I find a new spool seems to work best. Rod.