Slow Cranking Major

bluecraig0776 · Post by **bluecraig0776** » Sat Jun 26, 2010 9:14 pm

Hey folks,
Since rebuilding the old girl she just won't fire up. It's cranking very slowly as if battery is flat but I had jump leads attached to another vehicle.

Could it be an earth problem?

Nick · Post by **Nick** » Sun Jun 27, 2010 10:21 am

could either be an earth problem, or your starter motor is getting knackered, or more seriously the engine could be too tight. Did you replace the main or conrod bearings? And did it turn over by hand easy enough?

John · Post by **John** » Sun Jun 27, 2010 8:40 pm

Best to remove all leads i.e. both battery, earth strap, battery to solenoid etc., check for continuity, and start again. If any lead is making a poor connection, likely it will feel hot.

And of course, with a rebuild, all the torque settings were checked and rechecked... ?

bluecraig0776 · Post by **bluecraig0776** » Sun Jun 27, 2010 11:01 pm

Thanks for your replies I will check all leads etc tomorrow. Engine turns over fine by hand

Ian · Post by **Ian** » Mon Jun 28, 2010 12:17 am

bump start her, and let her battery charge up

Post by **Brian** » Mon Jun 28, 2010 7:30 am

Did you paint the block where the starter fits or the starter itself?

super6954 · Post by **super6954** » Mon Jun 28, 2010 4:19 pm

When I rebuild motors I warn my customers that they may need a new starter in a few weeks. I find with the rebuilt motor the compression is a lot higher and the strain on the starter will kill it in a short time if it's not 100%. So it could be that as stated before. I have rebuilt majors that started good when worn out and then done the motor replaced everything as it was with the electrics and then found the starter was not up to it.
Its part of the fun of fixing old Tractors.
Regards Robert

bluecraig0776 · Post by **bluecraig0776** » Mon Jun 28, 2010 9:17 pm

Hi folks thanks for all your replies. I didn't remove the starter when I painted it I just left it on. I haven't had a chance to work on her tonight but hopefully tomorrow

Scruff · Post by **Scruff** » Mon Jun 28, 2010 9:41 pm

Hi guys, I just joined yesterday and I have a similar problem I think. I have just done up a 1962 Super and she starts and runs lovely but when she is hot the starter wont turn her over. Leave it for 20 minutes and she starts right up again without a problem. I replaced the big end shells, the mains and the piston rings during the rebuild and it turned over freely by hand. Is it the starter or is the engine too tight? Your help would be very much appreciated.

essex pete · Post by **essex pete** » Mon Jun 28, 2010 9:52 pm

Scruff wrote:Hi guys, I just joined yesterday and I have a similar problem I think. I have just done up a 1962 Super and she starts and runs lovely but when she is hot the starter wont turn her over. Leave it for 20 minutes and she starts right up again without a problem. I replaced the big end shells, the mains and the piston rings during the rebuild and it turned over freely by hand. Is it the starter or is the engine too tight? Your help would be very much appreciated.

I have had the same problem with more modern tractor. The starter could be at fault. I think the internal resistance can change with heat and more marked when something is amiss or worn.
IIRR the commutator was cleaned up.

Scruff · Post by **Scruff** » Mon Jun 28, 2010 10:07 pm

Thanks Pete. If you think it is the starter getting hot I will take it off and bump start the tractor, get it hot then put the starter back on and see if it will turn it over then. I'll let you know how it goes.

Post by **Brian** » Tue Jun 29, 2010 7:27 am

You have a faulty starter. I would suspect the internal windings.

I have had the same problem and my Super needs an engine overhaul. When cold, the starter spins he over and she starts but when hot she would not turn over. Second hand starter cured the problem.

Scruff · Post by **Scruff** » Sat Jul 03, 2010 1:26 pm

Thanks guys. I have fitted a new starter (ouch!) and it seems to have cured the problem.

Your next challenge...........

My hydraulics lift and lower fine, nice and smooth but when they are up in the position control they 'bounce' and when they are in draft control they fall. I have replaced the main ram seal and all the o-rings I could find. I have freed the unload valve already as it wouldn't lift at all when I bought it but to no effect. Any ideas of what to do next would be gratefully recieved as my head hurts!

1962 Super Major.

Sorry to start my membership with nothing but questions but you guys seem to be pretty switched on with these things. I am learning all the time so one day may be able to help somebody.

I have tryed to put a photo of the tractor on the page but cant figure out how. I will persevere.

Scruff.

Post by **Brian** » Sat Jul 03, 2010 3:56 pm

Two things to remember about Super hydraulics.

1. They are supposed to correct (bounce).

2. They are supposed to drop.

What you need to know is the number of corrections in a 30 sec. period. 8 to 10 is considered normal. More than this and you have an internal leak. If you have an auxillary service chest with a knob you pull for external services, pull the knob out. If the lift stops dropping, your leak is, control valve, unload valve. If it continues to drop it is piston seal, "O" rings on the ram cylinder or aux service chest, ram cylinder safety valve.

When you select draft control, they should drop about 1/2", if they drop right down I would suspect linkage adjustment or bent linkage.

Scruff · Post by **Scruff** » Sat Jul 03, 2010 4:24 pm

Thanks Brian, I will time the bounces. When you say you suspect the linkage adjustment do you mean the internal linkage on the draft/position control lever?

Scruff.

bluecraig0776 · Post by **bluecraig0776** » Sun Jul 04, 2010 4:13 pm

Hi folks, just to let you know I removed battery, gave it a boost on the charger, cleaned up the terminals etc and she fired up no problem.

Thanks for your help.

Scruff · Post by **Scruff** » Mon Jul 05, 2010 2:11 pm

Brian, thanks for your help. I timed the bounces and it is anywhere between 15-25 per 30 seconds depending on where in the quadrant you have the lever. I pulled out the aux service knob and the drop stopped. Since I have already resealed the unload valve it would point to the control valve.

Thanks again for the help.

Scruff.

Post by **Brian** » Mon Jul 05, 2010 4:20 pm

The seal on the unload valve is not important, it is the ball on the seat that could be the cause. Did you make sure there were no marks on the ball?

If the control valve is leaking it means that the sealing lands have been damaged or worn. The cure is a new/replacement valve and probably sleeve as well.

On the valve there are drops of paint, these indicate the size of valve you need. The valve has to be a perfect fit, this is why I always say do not clean it other than with metal polish. If you use emery or wet and dry the valve can be scratched and the smallest scratch will allow oil to leak under pressure.

To check if the valve is the correct fit the ram cylinder should be vertical. A lubricated valve should then slowly fall through the bush. If it drops through quickly then you will need the next size up and this will need lapping in with metal polish until it falls gently through. (A long and laborious job).

Scruff · Post by **Scruff** » Mon Jul 05, 2010 8:10 pm

Ok Brian, thanks.

I dont remember seeing any marks on the unload valve ball (but was I looking that hard?). I do remember the control valve being discoloured. This tractor had stood for 18 years before I rescued it. there was quite a bit of water in the bottom of the back end and the unload valve was stuck. I changed the seals but no more. I will no better next time.

I have rallies for the next month so wont be taking the top off for a while. I will look then.

Scruff.