802A cooling

[Sgt Jiggins]

Howdy,

While looking at my 802a running the other day, I noticed 2 things: the temp gauge was non-functional (needle at 7 o'clock position) and the coolant bottle was low. Famous last words: the temp gauge "was working last time I fired it up".

I checked the radiator (full) and added a bit more coolant to the bottle. Bottle isn't leaking (that I can tell?). I'm thinking one/combination of 4 things:

1)air bubble from **** somewhere in there
2)the thermostat is bad and not allowing coolant to flow
3)the electronics behind SW6 are bad (which almost worries me as much as #4 below)
4)the pump is toast.

I looked into TM 9-6115-641-10 and TM 9-6115-641-24. With the troubleshooting section of TM 9-6115-641-24 seeming to point to TM 9-2815-252-24. I leafed through TM 9-2815-252-24 and didn't see any more in the troubleshooting section there either.
Before I tear this thing down a bit, I figured I'd ask if there are any common failure points to check.

Thanks,
SJ

 

[Light in the Dark]

Gauges crap out pretty regularly on the 802... enhanced vibration due to the twin cylinders. Check the wiring on the gauge first... does the needle drop to zero when unhooked or does it do anything after you turn the set on... or is it literally frozen in that position?

 

[Zed254]

My 802 vibrated so bad it broke one of the Oil sender wires....twice!! I added around 4 inches to each conductor to provide more 'wiggle' and it's been good for around 40 hours. And the beede gauges are problematic if you tighten the mounting screws too tightly.

I just finished changing mine out when the fuel gauge crapped out. Nothing matches, but they DO function nicely....

 

[Ray70]

Are you having any cooling problem other than the temp gage not working? It sounds like your gage just broke, from your description you don't indicate any other overheating problem. Rad. is full, just fill the bottle to the mark and keep an eye on it. It's intended to go up and down a little as the coolant heats and expands, then it draws back in when it cools or if the radiator had an air bubble it would draw some in once it burped out the air.
If your gage is at 7:00 it's broken or you have an electrical problem, 7:00 is way out of the operating scale range.
If the wiring and sender are good you can get a Faria Euro black 2" gage for cheap but you also need to use the adapter board to convert from 12V to 24V, it bolts to the back of the gage and just has a resistor in line. cost is about $12 for the board.
Some others have found similar gages that drop right is as well.

 

[Zed254]

Look for a gauge that is 24 volts, with a high temperature of 240F to match your sender. I like Datcon and Teleflex. Did not see too much on Ebay but this outfit has a Datcon that should work: http://www.partdeal.com/datcon-52mm...e-100-240f-24v-with-black-bezel-06343-05.html


The first replacement I bought had a range of 280 F and it was NOT very accurate so is in a box on a shelf. My notes say..... Water Temp Gauge: ISSPRO R8750, VDO A2C60000963, Datcon 06343-05

.....but first run through the gauge troubleshooting section in TM - it could be the sender or a broken wire.

 

[Sgt Jiggins]

I'm going to check and see if the wires just vibrated loose. It didn't 'look' that way when I gave it a quick check last night, but I'll get more into it this evening.

I don't know what to think about the temp. It doesn't 'smell' hot by any means, but other than that, I haven't a clue. I can't hold my hand on the block like I can with the engine in my SEE. (I'm always amazed at just how low the temp on that thing stays though.)

Radiator is not leaking nor is coolant fluctuating like it did last time (first time after changing coolant out). I had wondered if that was just normal cycling and after what Ray70 said above, I'm pretty much ok with that bit of it. The coolant is clean, as is the oil. So I have no reason to suspect worse. And it cranks/runs just fine. Just nervous without that temp gauge.

 

[Sgt Jiggins]

Even if the temp gauge isn't working, the 'emergency stop' feature related to coolant temp would shut it down, no?

 

[kloppk]

Even if the temp gauge isn't working, the 'emergency stop' feature related to coolant temp would shut it down, no?

Yes, there is a High Temperature switch in the engine that will shut it down as long as Battle Short is OFF.
The Coolant Temp gauge circuit is independent from the High Temp switch circuit.

 

[LEOK]

Start a cold unit and monitor the Temps of upper and lower hose

 

[Sgt Jiggins]

Wanted to throw out there that I found a NOS beede gauge on ebay for $62 (including $12 S&H). The seller has quite a few left if anyone is looking.

 

[Sgt Jiggins]

It was the gauge. Just swapped it out and it was good to go. What I did notice was that it was running a bit warmer than I'd seen previously (if the gauge was to be believed). Mostly it'd been around 180F in the past. But maybe it's just a higher ambient temp (92F) today that's causing it. It was operating around 210-215F. Is this normal/safe?

 

[Light in the Dark]

Are you 100% certain its the same gauge? Reason being is that if the sender isnt matched to the gauge, the readings can be off (like the coolant temp gauge I have in my unit reads about 215, when I know its really closer to 185). I knew it was going to be off, but the price made me not care so much

 

[Sgt Jiggins]

It's a physically different gauge even, yes, so it may well be mis-matched as you suggest. I guess I could get out the infrared/flir device and validate it. Where is the best place to gauge the temp?

 

[Daybreak]

It's a physically different gauge even, yes, so it may well be mis-matched as you suggest. I guess I could get out the infrared/flir device and validate it. Where is the best place to gauge the temp?

Howdy,
You would just shoot the little laser locator wherever you want that temp. Probably next to the water coolant temp sender, and general block areas.

 

[Zed254]

....What I did notice was that it was running a bit warmer than I'd seen previously (if the gauge was to be believed). Mostly it'd been around 180F in the past. But maybe it's just a higher ambient temp (92F) today that's causing it. It was operating around 210-215F. Is this normal/safe?

These machines have a sender that match a 240 F high temperature. You want a 24 volt gauge that reads a max of 240F. You bought a 250F gauge. I suspect your gauge is calibrated to a different ohm setting than the installed sender.....just like the 280F gauge I first bought and mentioned in post #5.

Here is some info on Teleflex senders: gfretwell.com/electrical/teleflex%20senders.pdf It speaks of temperature ranges, but does not give a detailed ohms range for the sender. It give a few specific values and it does mention a 250F gauge needs a different sender than a 240F gauge.

I'm kind of surprised the 10 degrees makes that much of a difference, though. Mine was off by 30F on the high point and it was quite inaccurate on my 803.

Faria 250F ohm range: https://fariabeede.com/site_manuals/IS0085d.pdf

 

[pjwest03]

I've been buying VDO gauges that come with the matching sender. That way way i don't have to think too hard about it. Many of the VDO gauges are available in 24 volt versions or 12/24 volt version for the ones with LED lighting. The Viewline Onyx gauges are ~$60 with the matching sender and thread adapter set.

 

[Bmxenbrett]

You need a temp gun to really see whats going on here. 215* is a bit hot to me. 190-200 would be better.

A temp gun is roughly $20 at harbor freight.