I have mentioned before that my alternator output and engine batteries are both on the center stud. Went to remove the nut to move the engine battery wire to the empty stud where it belongs. That way my Echo-Charger will keep it charged instead of periodically using my boost switch. The nut would not turn.
Put some Liquid Wrench on it; still tight. put some more on, waited a couple of minutes, tapped it with the wrench, added some more LQ and waited. Still will not move. Then I tried PB Blaster, still no joy.
I have several concerns:
I may be able to force it (especially with a cheater), but my concern is the stud itself. If I physically force it to turn, will it break the internal stud connection, and destroy my isolator?
I might be able to get a wrench on the back of the connecting wires, but I am afraid it might touch the heat sink fins. Is the heat sink grounded?
I thought of using a heat gun, but am concerned about the earlier penetrants catching fire. Obviously the heat shrunk cables are at the same location. But, would heat help loosen the nut?
I am very concerned about a second wrench, or a broken stud putting three fully charged red tops into play. Okay, since I have busbars, I can remove one cable, and avoid that; will do that when I go back out there.
What are my options? What is the recommended procedure?
What would y'all do to get past this step?
Thanks,
Trent
Trent,
Best advice is to use a good penetrating oil for a couple of more days. Then perhaps a little light, sharp "percussive persuasion". Breaking the stud would render the isolator recycle material.
I AM concerned about what that connection is doing to the battery. The "center stud" with the wire from the B+ terminal of the alternator, will have EXCESSIVELY high voltage (.7 VDC higher than either of the outer studs) and could easily damage the battery.
Wonder if the wire was moved because the isolator had already failed-- i.e. it was not passing power through the diode to the stud to the chassis battery. Easy to test.
With engine running, check voltage at center lug and at that outer lug. The outer lug should have about .7 VDC less than at the center stud and be in the range of 14.0-14.3.
Like Brett says, leave it for a couple of days. Applying heat with a micro torch and then more liquid wrench never hurts. Takes time for the stuff to penetrate and do it's thing. I like to replace all the washers/nuts with stainless. Get files ready to flatten the mating surfaces on the cables.
Isolators are not that expensive if you break yours. You just have to match the alternator output or a little more.
Pierce
One trick my dad showed me years ago was to put penetrating oil on the threads and then apply vibration ( I have used a palm sander body pressed against the bolt or threads)
Often fine vibrations will move material in ways that are just amazing. If you have ever seen high slump concrete turn to liquid with a concrete vibrator you will know what I mean.
Good luck!
Len
If you have access to acetone and transmission fluid; mix it 50/50 spray through spray bottle onto the nut and keep adding everytime you think of it.
Old farmer trick to unseize tractors bought at auction was to put the same mixture in the cylinders, places on trailer in gear and chained down for traveling home. Lots of time the tractors cylinders would be broke loose and able to start. Good luck.
Yup, one of the better penetrating oils.
Brett,
Thank you for the advice. Several people have suggested giving the penetrating oil several days to do its thing. I remember seeing a link somewhere (maybe here) to a comparison test of different penetrating formulas. My recollection is that (to my surprise) Liquid Wrench was one of the higher scoring. Although there was a "home brew" (maybe the acetone/transmission fluid?) mix that scored very high also.
This certainly sounds easy and straight forward, but I have a couple of concerns. We are often warned not to start our diesel engines if we cannot drive several miles before turning it off. I suspect that since it would only be on for a short time, it might not be a problem?
My other concern stems from the RV being up on eight 12" HF "safety stands". Would running the engine for a short time cause any problems from vibration? If it runs long enough to fill the air tanks, do I risk the air bags lifting the frame enough to allow one or more of the safety stands falling to the ground?
It is amazing how many alligators we can find when we just wanted to drain the swamp. :o
Thanks,
Trent
With the engine battery cable located on center post you don't need to start the engine. If there is any voltage on the other terminal at all the isolator is probably working. Usually when they fail there is not conduction between the posts. Like Brett said the expected voltage drop would be .7 volts going from the center terminal to outer ones.
Agree. That is close enough to "real world" that you should be able to tell if the isolator is good/bad.
While not a good practice to just start them to warm up, modern oils have a lot of anti rust/corrosion additives built in. No problem to start to move, check voltage, etc. Just not good to get in to the habit on a regular basis.
Once oil temp goes over about 185 degrees, the condensation starts to evaporate. Need about 20 miles to do that.
Pierce
Sounds like you don't really need to start the engine to check the isolator, following the advice above.
However, if you ever DO want to run the engine when you have the coach up on safety blocks, don't worry about it. It won't hurt a thing - I have done it many times. The vibration won't be a problem, assuming the coach is actually sitting down on the blocks. With 30,000+ pounds of coach holding them in place, they aren't going anywhere.
As for the air suspension, it is also not a concern. When you start the engine, the HWH system will try to go to travel height - i.e. it will attempt to let air
out of the bags (if there is any pressure still in them). The only way you are getting the coach up off the stands is by using the manual "RAISE" button on the control pad.
There is a product that is similar to pb blaster but better. Its called Kroll and its hard to find but I found it to be able to loosen anything. Above suggestions about letting it soak and also tapping on the socket or wrench is like vibration might also work.
Chuck,
That reminds me of something. When I raised it up, I initially used the "raise all" button. Went back to start installing them, and it was only up about 11". I went back inside and used the front raise button and it went up to 13.5"set the stands and lowered the front to the stands. Raised the back the rest of the way, and it also went up to 13.5".
Did I just not let the raise all button work long enough, or did the raise front and raise rear actually have additional lift?
Trent
Yup, used it on the bolts on the exhaust manifold bolts of a Cummins ISL a month ago. Good (expensive) stuff.
For most stuff I use the acetone/ATF as it is a fraction of the price. But, a broken bolt in an ISL head.........
Yes.
Sometimes it takes a while to achieve full erection, especially in the rear.
(There are several wrong ways to read that sentence, but I trust our Forum members are above such crass thoughts)
Be nice! It could be your sentence.
Ignoring the health problems associated with acetone, I see another possible problem.
Acetone is extremely volatile. When mixed with a non volatile substance like transmission fluid, is there not the possibility that the acetone in the mixture will evaporate, leaving only transmission fluid?
Just curious,
Trent
here are the results
Penetrating Oil Showdown!!! | The H.A.M.B. (http://www.jalopyjournal.com/forum/threads/penetrating-oil-showdown.350800/)
Trent,
- (as others have mentioned), any penetrant needs to "set", in order for it to work.
- From my experience, Mouse Milk penetrant works better and is not as flammable.
- An isolator case is usually grounded to the frame - easy to verify with a DVM/VOM.
- Remove (+) cables from your isolator at the other end (your Battery bus bars).
- Each isolator post should have an inner nut, then a round wire lug, then an outer nut sequence landed on the stud. At least that is the way it is on mine.
- Toolsmanship: To confine torque to the stud (and prevent damage to the isolator), use two slightly offset wrenches and then squeeze them together with one hand. That way there is no torque applied to anything except the stud between the two nuts. If you have no inner nut, use a pair of vise grips set onto the round wire lug and then a slightly offset closed end wrench, squeeze them together to free the nut slightly, work in more penetrant, work the nut off slowly using more penetrant.
[/list]
High heat and flammable solvents may not be the best things to use around the somewhat soluble potting compound (that black stuff that is molded into the face of the Isolator cooling fins).
HTH,
Neal
My small motorcycle motor builds routinely have badly stuck filter retaining fasteners.
My routine removal method is to use an air impact wrench and remove the offending fastener with the tools percussive persuasion quickly.
Obviously a corroded shaft may have enough friction to slow the removal and failure is a possibility.
A double nut on the exposed shaft tensioned against each other and a wrench applied would allow more force to be applied to the stuck fastener.
This presupposes that some sufficient shaft is exposed
As a heads up, Kroll is running a Google Deal of 2 cans of Kroll for $14 + shipping.
Google Deal (http://www.kanolabs.com/google/?gclid=CJ2ljsi5ptECFYO4wAod89UKjA)
Here are the results of my voltage measurements at the isolator studs (three), with the engine and boost switch off, and plugged into 50 amp shore power:
Left Stud (House battery) Center Stud (Alt + Engine batt) Right Stud (No Connection)
14.3 VDC 13.1 VDC 12.6 VDC
Using the cheap digital voltmeters plugged into the two 12VDC outlets on the dash:
Upper Outlet (house battery): 13.8 VDC
Lower Outlet (engine battery): 12.7 VDC
Would someone who understands what these readings mean, please let me know what, if anything, information this data reveals about my battery systems and the isolator?
Thank you,
Trent
Alan,
Thanks, I ordered mine.
Trent
It appears your isolator is good, and voltages about normal. While on shore power the engine batteries are not charged. By your engine battery being on the center stud when running you would be putting too muck voltage to the start batteries. Center stud is .4 volts higher than the left and right studs.
I agree with Craneman. Your isolator appears to be working. Next step would be to check the voltage with the engine running.
One possibility that hasn't been mentioned yet is whoever put the engine battery on the center post might have also turned the voltage output down on the alternator (or moved the sense wire with it). This would make it such that while driving the engine battery would get a full charge and the house batteries would get a mild "float" like charge that would take much longer to reach 100%. Not necessarily bad and might be a good way to prevent over taxing the alternator if you started your days drive with depleted house battery from boon-docking. You could always turn on the boost solenoid if you want to bring up fully right away along with the engine battery.
You also now know that your "cheap digital voltmeters" read about .5 volts lower than actual battery voltage. Good thing to know!
The isolator may or may not be working, BUT YOUR CHARGING SYSTEM CAN NOT WORK CORRECTLY. With the chassis battery connected to the center stud along with the alternator B+, charging will NOT be correct.
Depending on where the sense wire is:
If on center stud and/or some connection between isolator and chassis battery: house battery will never get full charge. It will receive about .7 VDC LESS than the chassis battery.
If on stud with house battery and/or some connection between that stud and the house bank: chassis battery will be OVER-charged by .7 VDC.
Said another way, both banks need to be at the same "status"/level, as there is a .7 VDC drop in voltage across the diodes in the battery isolator.
UPDATE!
After several applications of Kroil, I was finally able to get the nut off the center stud. I had disconnected the battery from the connecting wire and put a wrench behind the lugs. It fought me the whole way, never getting loose enough to turn by hand. Somehow, the nut must have become cross-threaded. That nut has no desire to go onto the stud. I tried the nut from the adjoining stud and it is a no-go also.
The stud appears to be 5/16 x 16 18 (or 24). Will use the proper die on the stud and try to "refresh" the threads. I have a very distant recollection that you are supposed to use the die backwards when trying to clean the threads. Does anyone know about that? I may try to use the proper tap to refresh the threads in the nut, but will probably just use a new one.
Any thoughts on how/why this happened, and the best way to try to fix it now?
Thanks,
Trent
Trent, first try to start the die nut on post with you hand. If not then use the t handle but be very sure you have it lined up right. Turning the die nut around is good if you just want to clean out a slightly damaged thread but yours sound like they are bad..
If yu cannot cut the thread clean maybe you can use the next size down ( I think it may be a 3/8 bolt you have but not sure without looking at ours). Anyway that is what I would do if the original is not able to be cleaned up
JohnH
Trent, I have used dies to fix threads, but they aren't really optimum for it, and neither are taps the best way to refresh bolt threads as both of these are designed to cut new threads. I have one of these sets (http://www.sears.com/craftsman-48-pc-sae-metric-thread-restorer-kit/p-00942275000P?sid=IDx01192011x000001&gclid=CPfh3ZPW59ECFUtqfgod85QIYQ&gclsrc=aw.ds#) that have both male and female thread repairing sets as well as thread files which are used on bolts and studs. In fact, before I got this set, I had often used the thread file first to make it easier to get the die started straight to repair bolts and studs. I would also just toss the nut as it is easily replaceable and the stud is 5/16-18 if coarse threaded and 5/16-24 if fine. Most likely coarse threaded. If the stud happens to be stainless steel, using a die would likely be next to impossible without breaking it loose inside the isolator.
Don
Use strong glasses and a small file to clean up the threads. Then chase threads with a die. Install new stainless nuts/washers. Betting all threads will be UNC (coarse thread).
Pierce
I hesitate to use stainless nuts on any thing I might have to take apart. They have a nasty habit of spalling and then they are almost impossible to get off. There are anti-spalling coatings you can use to help prevent this. I use a plated nut after coating the stud and nut with CorrosionX. My Sterling isolator looks like it has big brass nuts.
I would not use stainless nuts either.
I use brass or bronze nuts which are readily available at marine and hardware stores.
Brass or bronze are great for electric connections and will not corrode. I would also continue to try and run a new nut on the stud. Even if its cross threaded it should become easier to turn. Take your time.
I called PowerLine (Hehr Power Systems) today to ask about disassembling the isolator to replace the center stud. He said it could not be removed the black stuff is part of the manufacturing process and cannot be undone. He said if I tried I would turn it into a brick.
He said I should be able to rethread it. I told him I was having problems getting into a position where I could swing a die wrench. He said to just remove it and put it on my workbench.
I removed all the cable connections and tried to remove the four (#2 square drive) screws. None of the four showed any interest in leaving. I put Kroil on all four screws, but one application did not do it. I have an impact driver from my motorcycle days. Would that possibly help to loosen them?
Thanks,
Trent
Trent, before you go to that extreme do you have one of the little propane torch's, and if so just heat the nuts up while trying to stay clear of the bolt part (studs). This should expand the nut a hair and they will them come off. Before it cools down spray with release stuff and heat again if needed. It will work.
JohnH
John,
I already have three naked threaded studs.
I am now trying to remove the four small screws that hold my isolator to the "firewall" under the bed. I can then rethread the center stud, reinstall it and the cables, and be a happy camper.
Speaking of happy campers, I was at Sam's Club and noticed they had some 15" x 20" x 1/2" cutting boards. They look like they would do a lot better job than the existing cruddy looking metal plates that now hold my isolator, solenoids, relays and miscellaneous stuff under the bed. Would that kind of material be up to the task, or is it too fragile?
Trent
Cutting boards are typically made of a polyethylene plastic (like the marine"lumber", Starboard). The stuff is quite durable and holds screws like nobody's business but softens when heated. I would think that heating in the engine compartment and possible heat disappation by the isolator heat sink might cause it to sag over time. I am going to redo my isolator component gboard with some 3/16" or 1/4" aluminum. That area contains the isolator, two Cole Hersey solinoids, some Bosch relays, and some other assorted stuff. I will be replacing the isolator with a Sterling ProSplit-R Zero Volt Drop Marine Battery Isolator (12V, 250 Amp, 3 Output)
Sterling ProSplit-R – Zero Voltage Drop Battery Isolator (http://baymarinesupply.com/wiring/sterling-prosplit-r-zero-voltage-drop-battery-isolator.html)
and adding several other components to the mix on that board as well as the Sterling 240 Amp alternator to battery charger to the other side of that wall, so there will be a lot of moving of components around. In preparation for the fun I have removed the failing engine compartment insulation. I considered using some Starboard, but I decided on the aluminum instead... won't rust like steel and will stand up to heat as well as act as a heat sink for those electrical components.
Don
And knowing the high quality standards of your work, it will be polished to a mirror finish before installation. 8)
I would not hesitate to just break off the screws holding the isolator in place. Worse case is you drill new mounting holes, or better yet just replace the metal panel.
FINAL UPDATE!!!
I was able to get three of the four screws that attached the isolator to my coach. The head broke off of the fourth one when I tried using a pair of vice grips to remove it. Finally, I was able to take the isolator to my "workbench" (breakfast room table). After careful inspection, I discovered that one of the threads that had been under the nut had broken off. I suspect the reason it was so hard to remove was the broken thread particles were trapped under the nut and were not ready to fly the coop. Some of the threads at the end of the stud were also cruddy.
I used a small triangular file to clean the threads near the end and filed the end of it to a slight taper. I was then able to get my die cutter onto it and refresh the threads. I don't mean to gloss over this activity, but it did take me several hours of work to get it done. Afterwards, I could run a new nut easily up and down the stud with my finger tips,
I remounted the isolator with three new screws. the broken stud was located on the bottom side and I just used it to help locate the proper position. It provides help in the keeping the isolator from sliding down. The other three screws provide a solid grip.
I attached the cables to the proper studs and the Echo charger is working properly. [Okay, okay; I am glossing over the fact that I initially had the echo charger wires on the wrong studs. This led to the green LED to flash slowly and not work properly. When I reversed them (now wired properly) the echo charger showed a steady green LED, indicating proper operation.] My cheap China LED voltmeters show about 13.7 for the coach batteries, and 13.1 for the engine batteries.
Thanks for all the advice and suggestions I got from the brain trust,
Trent
EPILOG!!!!!
Went out to check the alternator connections to see what they read after several days. The RV is plugged into 50 amp shore power; The Echo Charger is properly connected to the engine and house battery connections at the isolator. The reading on the CCLV (Cheap Chinese LED voltmeters) was 13.41 and 13.47, respectively. The voltage on the sense/(DUVAC) connector using my CHFV (Cheap Harbor Freight Voltmeter) was 13.41; the voltage on the switch connector was zero (+/- noise) using my CHFV.
Turned the ignition key to the ON position; got the sound of dash turning on, dinging, etc.. Walked back to the engine compartment and heard a motor running noise as I walked by the side of the transmission. The noise was even louder at the open engine door, but it eventually stopped. The sense connector read about 12.6 and the switch connector about 11.9.
Went back to the dash; the CCLV read 12.2 for the engine. Turned the ignition key OFF and within a minute read 12.5 and 13.6. After a few more minutes, the engine battery was 12.9 and the house battery was still 13.6. Scratched my head until it started bleeding and came in to report this to my brain trust.
The starter was never engaged, and the lights were off. What the heck caused the engine battery bank (three fairly new red tops) to draw down so much in the ON position? What was the blower-motor-sound back near the engine?
I know I will find out more when I crank the engine on and check the readings, but I am reluctant to do that until I am ready to fill the air bags and remove the safety stands. Speaking of which, while warming up the engine, do we want low idle or fast idle?
Since I know less about this stuff than most of you, I welcome any suggestions, observations, or advice on what you can determine from today's report.
Thank you,
Trent
Trent,
With ignition just turned on, the INTAKE MANIFOLD HEATER is on. And the electrical noise was likely the electric fuel pump.
That heater grid can pull a lot of amps.
Thanks, Brett! Voltages are back to normal.
Trent
Is the electric fuel pump only on the ISC? I don't seem to have one on my '99 ISM
yes ISC has that electric pump (which I changed a year ago) Dave metzger got it for me and brad delivered it to me 2yrs ago, wow how time flies.
Thanks Dave, love you.
JohnH
No your ISM doesn't have an electric fuel pump. No lift pump just the main injection pump sucking fuel from the tank.