Battery Boiling / Rotten Egg Smell CAT 320B

[conky]

Hi, I noticed after shutting down my machine there was something wrong. There was a really nasty rotten egg smell and then after removing my hearing protection I heard a bubbling noise. I traced it to the batteries and saw white liquid seeping from the top. I shut off the main switch and got out before a battery went poof in my face. So now I'm faced with fixing this problem. From what I have found out so far from internet research, it could be an alternator overcharging or a voltage regulator(?). Does anyone have any ideas what I should be looking for, I don't want to call a mechanic to diagnose/repair.

Machine is a CAT320B, 9KK series.

Thanks.

 

[heavyplant6]

Sounds like the alternator, the voltage regulator is build into most- I would suggest removing it and bring it to a good auto electrical repair shop. There will be a good chance your batteries will be U/S now unless your very lucky.

 

[Zed]

yeah sounds like your regulator, not sure about that model machine and what type of alternator you have, but some have a separate reg with adjuster. I have found with those though, if the machine was ok for many hours then suddenly started overcharging, then something has failed. If you have a multi meter, check the voltage output before you remove it. Also while you're at it, check all the cables, earths, for tightness and no corrosion. If you get a sparky to replace it, get them to test it after installation, output voltage and check current output with clamp meter.
Like heavyplant6 said, your battery could be U/S, try cleaning it, filling it with distilled water and then load test it. Or just bite the bullet and replace it, could save unwanted downtime if it fails after you get it digging again.

 

[CRAFT]

I had experienced the same sympthoms last year in my 312...... but before you go hog wild tearing out the Alt. ect .......... maybe check out the batteries first.... they are 12v batteries but it is a 24v system, (2 x 12v in series), and in my case the batteries were getting old and one or more of the cells started to short out..... in turn overcharging the batteries

It's a simple thing to check out ....just grab any 2 batts that are alike and run the ex with those and see if it still does the cooking ....... it's a cheaper fix if it is the batts .....
Worked for me ......cheers

 

[Nige]

There are 2 diffrent alternator Part Numbers listed for 320B 9KK-prefix. Both appear to be 100% rebuildable right down to individual part numbers for things like brushes. If your alternator has a data plate that would be a good place to start.

5I-7615 is fitted on 9KK1-820. Complete Reman alternator 10R-7562, rectifier assembly 087-8666, regulator assembly 099-0345.
5I-7982 is fitted on 9KK821-Up. No Reman Part #, rectifier assembly 5I-7996, regulator assembly 5I-7995.

We're assuming that the problem is regulator/rectifier related. It may be you have other issues in the alternator. A good auto-electrical shop should be able to tell you though.

 

[heavyplant6]

come on lads- this really isn't this hard- buy a $8 electrical tester- start the machine-bring the rev's upto 1500- check the running voltage- if it's over 26 to 28 it's the alternator- rip it off and give to a good shop to get it rebuilt.

 

[John C.]

Those alternators commonly run 29.5 volts without any problems.

Are the batteries made in the USA or are they original from Japan. The Asian batteries were made with a different chemical formulation in those days. They lasted forever. Eventually though they all go bad. I had a set in a big Komatsu dozer that shorted internally. The lead had shaken off the plates and filled the bottom of the battery up to the bottom level for the plates. This shorted out a cell and it boiled so hard the operator had to leave the machine. The gas was getting into the cab and he turned all red and was dizzy.

At any rate heavyplant6 is absolutely correct. A cheap multi-meter from Sears or Radio Shack will save you a ton of money.

 

[toomanymachines]

come on lads- this really isn't this hard- buy a $8 electrical tester- start the machine-bring the rev's upto 1500- check the running voltage- if it's over 26 to 28 it's the alternator- rip it off and give to a good shop to get it rebuilt.

Exactly what you need to do. And d o it quick, because if it is overcharging you may fry something electrical, not sure if this machine has any electronics in it or not. I think it would be even higher. I don't think 26 to 28 is too high. if it is 28 or higher then get it checked. As most 12 volt systems run 13.7 or 14 when charging.

 

[06Pete]

I think my 320L calls for 32 volts before it should show high I know the regulator should cut out at 28.7 as I just went through mine showing high voltage and it turned out to be a faulty computer. Buy a multi meter and then a full set of books life will be much easer.

 

[conky]

Hey guys, thanks for the info. I checked the running voltage and it was at 37-38. Way too much, so now I'm going to replace or rebuild the alternator. I know I will have to replace the two batteries that were sizzling. My main question is do I need to replace the other 2 batteries behind the main two as well? I never seen them smoking or bubbling or anything and oddly enough they didn't produce a reading on the voltmeter when tested. Oh and the batteries are CAT brand and about 5 years old.

Thanks again!

 

[CRAFT]

WOW ! ...you have 4 batteries in that 320 ??? .... my 312 and the 320CL only had 2 Cat batteries each......hmmmm

 

[jack345]

You may not have to replace those batteries , add water if needed and have them tested might be ok.

 

[Boiled Owl]

MY 320B had 4 also. Believe it was the "cold weather package" option. I never had trouble with the batteries, but likely would have only replaced 2 in the event of failure.

 

[toomanymachines]

I would take them and top them all up with distilled water. charge them and load test them. If they are 5 years old they have had most of the life taken out of them. Depends if you want to save money or keep ahead of problems. I have never seen a battery last past 7 years, but I am sure it is possible.

 

[Nige]

Hey guys, thanks for the info. I checked the running voltage and it was at 37-38. Way too much, so now I'm going to replace or rebuild the alternator. I know I will have to replace the two batteries that were sizzling. My main question is do I need to replace the other 2 batteries behind the main two as well? I never seen them smoking or bubbling or anything and oddly enough they didn't produce a reading on the voltmeter when tested. Oh and the batteries are CAT brand and about 5 years old.

Thanks again!

Go to my post above, check your alternator part number (should be on a tag on the unit itself) and you'll find the relevant Part Numbers for the regulator for both types of alternator. With the alternator pushing out 38 volts I would say the regulator has failed, but at the same time I think I would replace the rectifier as well if you have the unit apart.

 

[conky]

Problem Resolved - Replaced alternator and 2 batteries, no more smell or sizzles, charging below 28v now.

Thanks for the help as always.