JD 500C battery

[Derek22485]

I have a 1978 JD 500C loader backhoe. It runs great, once you get it started. Originally it was outfitted with a pair of 6V 780 CCA batteries, by the time I got it those had been replaced with a single 12V 1000 CCA battery. Sometimes it fires right up, most of the time it seems like there is just not enough juice to spin the motor...it hangs up like the battery is dead. I've got a new starter and new battery on it- most of the electric has been gutted out of it and I can't find any indication of battery drain. I know the alternator (recently replaced) is undersized and I'll address that in the near future....after I put a charge on the battery it usually fires right up. Short version of question: is 1000 CCA enough? It seems to me two 780 CCA in series calls for something in the neighborhood of 1500-1600.... Thoughts?

 

[Tx Jim]

I'll recommend to install and utilize during starting process a manual hyd pump destroking screw(parts key 6). DS screw when screwed down stop pump from trying to pump hyd oil relieving some stress on starter. Parts listed are for a hyd pump without a serial number plate. An electric DS device is available for a little over $200 USD
A4365R O-Ring - PACKING "O" RING 0.96 USD
R26448 O-Ring - O-RING, O-RING 1.54 USD
R27171 Screw - SCREW View/Update 7.89 USD
R27475 Fitting - BUSHING,ADJUSTING SCREW 5.53 USD
34H254 Spring Pin - PIN, SPRING 0.33 USD
*Subtotal 16.25 USD

 

[Derek22485]

Thanks-I'll try that. I appreciate you taking the time to provide the part numbers and costs....that's above and beyond.
I thought by exercising all the controls before attempting to start I would accomplish the same thing, no?

 

[Tx Jim]

Moving hyd controls will not relieve pressure unless when engaging starter BUT most common way is to move steering wheel rapidly back & forth while attempting to start to relieve pressure.